United soldering and rework station

Introduction

This is a two-channels combined soldering iron rework station for Hakko T12, JBC C245 and 858D Hot Air Gun based on STM32 micro controller. The soldering controller uses ili9341 TFT display with SPI interface without touch-screen. There are several display variants (2.2", 2.4", 2.8" or 3.2") in the market, so you can chose any of them that satisfies your requirements. Yet, you can use the IPS display based on ili9341v IC. The controller in main photo equipped with the 2.8" TFT display.

The soldering controller can manage any type of soldering iron (JBC or T12) and Hot Air Gun at the same time. In the main mode, you can activate the iron or Hot Air Gun or activate them simultaneously. The information about two devices is displayed on the main screen and each device is managed by a dedicated rotary encoder. There are two GX16-6 connectors in the controller that can be used to connect the soldering iron: in the front pannel and in the rear pannel. The read connector can be used to manage the JBC C245 tips and the front connector can be used to manage both types of iron, Hakko T12 or JBC. It is convenient to connect the JBC base stand to the rear connector and when you use the JBC iron without a base stand it can be connected to the front socket. You cannot connect the Hakko T12 and JBC irons to the front and rear connectors simultaneously, because the controller can manage only simgle soldering iron at a time.

To simplify managing devices two rotary encoders are used in the controller. The upper encoder manages the JBC or T12 soldering iron and the lower encoder deditated to the Hot Air Gun excusivelly. Also, the main menu is available through long-press the lower encoder.

The automatic mode switch that turn the Hot Air Gun off is still optional and can be placed on the rear panel, like mine. To simplify using JBC iron, you can buy the dedicated JBC base stand or implement optional push button to simulate JBC tip change and optional switch to simulate JBC on-hook feature when the JBC iron is not connected to the controller. Both optional switches and be placed near the JBC socket on the rear side of the controller.

UPDATE

Mar 14, 2025, v.1.01

• Added erasing flash procedure allowing completely format the data store and check it. See 'Erase flash' chapter for details.
• Fixed bug in adjusting the display brightness

Let's get started

This project has several features:

• The controller manages both soldering iron types (Hakko T12 and JBC C245) by means a single ADC channel that measures the temperature. You can use either type of iron consequently.
• The controller has mini USB port and simulates USB flash drive allowing PC connection to load and save configuration data, for instance, native language support files.
• The controller allows managing Hot Air Gun and soldering iron independently and simultaneously. To simplify device management, the controller has dedicated rotary encoder for each device: soldering iron and Hot Air Gun. The reed switch of the Hakko 858D Hot Air Gun handle is used to activate rework capability.
• The JBC iron can be switched off or turning to the low-power mode when it is placed on the optional base stand depending on configuration parameters in the main menu.
• Hot Air Gun is powered by a whole sine half-period voltage peaks from AC outlet and do not disturb the AC power source of your room.
• The controller checks the hakko T12 soldering tip is connected by short peaks of a current through the tip. When the tip is removed from the handle, the controller automatically initiates the tip change procedure. This simplifies managing of Hakko T12 soldering tips.
• The controller checks the Hot Air Gun is connected and its fan is working properly before applying power to the Hot Air Gun heater. This increase the safety of the controller.
• The controller would keep the Hot Air Gun fan working until the Air Gun become cold. Optional main power switch can be used to automaticslly turn-off the entire controller after the Hot Air Gun become cold. This allows you to lieave your workplace immediately and guarantee the Hot Air Gun will be cooled safely.
• The fan speed of the Hot Air gun can be managed automatically as soon as the Gun is powered off. This decrease the time requred to cool down the Hot Air Gun and ensure that the hot air not harm your workplace environment.
• The controller uses ambient temperature sensor inside the FX9501 handle of the hakko T12 iron or inside the STM32 MCU to correct the tip temperature measured by the soldering tip thermo-couple.
• The controller supports individual calibration of the T12 and JBC tips by four reference points, 200, 260, 330 and 400 degrees Celsius.
• The controller supports calibration of Hot Air Gun by four reference points, 200, 300 400 and 500 degrees Celsius.
• The dedicated calibration procedure is implemented in the controller to simplify the tip or Hot Air Gun calibration process.
• The maximum soldering iron or Hot Air Gun temperature can be limited in case if you do not heat-up your equipment to the highest temperatures. In this case, you can skip the hot calibration point during tip calibration procedure and prevent the soldering tip from getting dark.
• PID algorithm used to manage the supplied power to soldering iron or Hot Air Gun. This allows to keep the preset temperature very accurate.
• The temperature can be displayed in two degrees: Celsius or Fahrenheit.
• The standby (low power) mode implemented using optional hardware tilt switch in the hakko T12 handle.

You can install optional switches and buttons if you are going to use single device and do not connect other devices to the controller.

• Optional JBC switch can be used when you do not use the additional base stand for the JBC iron. This switch connected in parallel with the 'standby' connector of the JBC base stand. This switch can be placed near the rear JBC connector.
• Optional JBC tip change push button can be used if you are not implementing the additional JBC base stand at all. This button can initiate the JBC tip change procedure. This button can be placed near the rear JBC connector.
• Optional automatic mode switch can be used when you do not connect the Hot Air Gun to the controller to switch the Hot Air Gun off for sure. The optional switch is connected in parallel with the reed switch of Hot Air Gun.

The controller PCBs

To increase its reusability, the complete schematics was split in 3 separate PCBs: the main PCB, high-voltage PCB and display PCB. The component list of each PCB is available on EasyEDA site.

• The main PCB conntains the main low-voltage components: STM32F103RET6 MCU, op-amps, voltage dc-dc converter and regulator, mosfets that manage the soldering iron and Hot Air Gun fan. You can use the STM32F103RET6 development board to simplify soldering the controller. But in this case you should develop the main PCB by yourself.
• The high-voltage PCB that manages the Hot Air Gun contains the high-voltage part of the project: the triac, optional relay and opto-couplers that creates galvanic isolation from the main board.
• The display PCB contains the TFT display and two rotary encoders.

The main board

The main board schematics available in EasyEda site, where you can vew it and order the board if you wish. The schametics of the main board was separated to 4 pages.

The main board picture is shown below. As far as you can see, there are several connectors on the board that should be explained.

• J1 is a SWD programming interface to upload the firmware to the MCU.
• J2 is a optional serial port using to debug the controller. You can skip it soldering.
• J3 is a screw-type 24v input power connector, please ensure the polarity, "+24" means the +24 volts AC-DC power supplier terminal, the "-24" means the groung terminal of the same power supplier.
• J4 is an optional auto-switch connector to duplicate the Hot Air Gun Reed switch.
• J5 is a supplimentary hakko T12 connector.
• J6 is a IDC-type connector for the display PCB.
• J7 is an interface to the high-voltage PCB to manage the Hot Air Gun.
• J8 is a low-voltage part of Hot Air Gun, reed switch, thermo sensor, fan.
• J9 is a screw-type power connector for Hakko T12 and JBC, please ensure the.
• J10 is a supplimentary JBC iron connector.
• J11 is a optional 5v connector that can be used instead of DC-DC 24v->5v internal converter if you have an alternative power source.

The high-voltage pcb is also available in EasyEda site. The schematics contains the TRIAC and opto-coipler modules allowing to isolate the board from low-voltage part of the project.

The High-voltage PCB

The high-voltage board has wide lines and should be ordered with 2oz depth to allow high current to the Hot Air Gun heater. It would be very expensive to order the complete board with 2 oz depth, so the high-voltage part was split to a separate PCB. Yet, the interface connector is completely isolated from AC power via two opto-couplers OK1 and OK2. The EasyEda page contains several versions of the pcb you can select the one you like depending on where your connectors are on the case.

There are 4 screw-type connectors on the left side of the board and one interface connector on the right side.

• JP3 is a AC power connector, connect here the AC 220 volts from AC outlet. Do not forget to install 5A fuse before. The fuse can be placed on the rear pannel of the case for instance.
• JP6 is a optional main power switch connector. Connect the main switch here or just short the pins with a piece of wire.
• JP4 is a Hot Air Gun heater connector.
• JP7 is a connector to supply AC power to the AC-DC 24v power supply.
• JP8 is an interface connector to the main board. It supplies the isolated interface to the Hot Air Gun.

The interface connector has 5 wires that manages the AC power board:

• "+24" is +24 volt from AC-DC power supply to activate K1 relay. You can remove this wire if you do not install the relay
• "gnd" is obliously ground wire
• "E" is a power enable signal (3.3 v), used to activate the relay. Can be skipped if you do not install the relay.
• "P" is a Hot Air Gun heater signal (3.3v), used to power the Hot Air Gun.
• "Z" is a AC zero cross signal from the High voltage PCB.

You can skip optional 24v RTE24024 relay from TE Connnectivity If it is unavailable in your country or if you do not want to implement the safety feature in this controller. This relay completely disconnects AC power from Hot Air Gun GX16-8 aviation plug on the front panel when the Hot Air Gun is not used. If you install optional auto switch you can completely disconnect the Hot Air Gun from the controller and it would be safe to touch the GX16-8 connector.

To remove the RTE24024 relay completely, you should solder the relay pins as shown on the picture bellow by violet lines. Also, you can remove R24, VT6 and D3 from the PCB together with the relay.

If you do not want to implement the main power switch of the controller, you should solder the pins of the main power switch JP6.

The display PCB

The display PCB allows to install the controller into the small case. The board files and description available on EasyEda site.

The schematics of the board is very simple. It contains two rotary encoders and TFT display only. Also, you can see the mosfet that manages the TFT display brightness.

The controller requires big size PCB to fit all the components so it is convenient to create the display separate board. Also, It is convenient to solder rotary encoders to the display board and use encoder neck to fix this board on the acrylic front panel.

This controller is working with ili9341 and ili9341v based TFT displays only. You can select the display size (2.2", 2.4", 2.8" or 3.2"). The display has sufficient resolution 320x240 to show required information. I used the 2.8" one to fit the case.

AC-DC power supply

The JBC tips requires much more powerfull power supply than Hakko T12 tips do. The JBC C245 tips resistance is about 2.6 Ohms, so the power supply should be capable to give you about 10A of current, more than 230 Watts. To power up the project, I would like to recommend Mean Well 300 W LOP-300 24v low-profile power supply. Despite of small form factor, it supply suffitient power to the soldering controller.

I would like to also recommend Mean Well EPP-300-24 power supply like shown on the picture below. This power supply has extra 5v power source that can be used to power the low-voltage part of the controller, You can use J11 connector on the main PCB to connect the 5v power source to the main board. In this case, you can skip soldering the DC-DC converter on the main PCB.

These are a high-quality power suppliers that can drive both JBC and T12 tips without any issue. The only disadvantage is that these power suppliers are not isolated ones. The JBC tips have feature that the termo-couple is connected to the tip body, so using switching power supply the 'Line' terminal from AC outlet goes to the body of the tip. Perhaps, it is not good idea to use switching power supply for this kind of tips, but I do not like the transformer power supply as soon as they have a very huge weight and big dimensions. I decided to use extra transformer power supply 220v->127v while working with the sensitive components. We can discuss in futher details the AC-DC power supply in the comments of this project.

JBC C245 soldering Tips

The JBC C245 soldering tips are up-to-date replacement of Hakko T12 ones: they are heating much more faster because have a much more powerful heater element. The JBC C245 tip has heater resistance about 2.6 ohms while the Hakko T12 tip resistance is about 9 ohms. As soon as both tips requires equal voltage to be supplied, the power of the JBC tip bigger than the Hakko T12.

The JBC tip also have a sensor inside that allows to keep the temperature very accurate. The heating element inside the tip is not connected consequently with the thermo couple this time.

The JBC tip connected to the controller by the following way: the Vout1 terminal is connected to the pin#2 of the J9 connector on the main PCB and then through the PR1 & PR2 resisters to the ground, the Vout1+ is connected to the pin #1 of the J10, the SENSEB terminal is connected to the pin#3 of the J11 connector. The thermo-couple generates the negative voltage with respect to the Vout1 terminal (controller ground) so it is not possible to use the Hakko T12 channel to control the JBC iron, The dedicated channel implemented in the controller to manage the JBC iron.

Caution: As soon as the heater resistance is low, the +24 volt terminal is about connected to the JBC tip body. The switching power suppliers are not isolated one and the AC power 'Line' can be detected on both output terminal of the power supply, so on the tip body. That is why the JBC soldering controller usually uses the transformer power supply. To partially resolve this problem, someone advices to connect the minus termianl of the power supply to the Earth Ground through high-voltage capacitor 470 nF.

Better to use AC/AC isolated transformer, for instance 220-> 127 volts or 220 -> 220 volts before the switching power supply to ensure the soldering tip safety. Unfortunately, to properly power the JBC tip, 10A capable power supply required. The transformer power supply capable to supply such big current, has big weight and is not convenient.

As soon as the JBC handle does not contain the tilt switch it is not convenient to use this handle without any additional equipment like optional JBC stand because you cannot put the iron to the standby mode easily. On the other hand, the JBC tip can reach the preset temperature very fastly and it is possible to completely turn-off the tip when you do not use it.

The JBC stand allows to put the JBC tip to the standby or completely off mode, yet it allows to initiate the tip change procedure. The controller supports the JBC stand: the JBC iron will be turn-on automatically when you pick-up the handle from the stand. The JBC iron will be turned-off or put to the standby mode when you put the handle to the stand. Yet, when you touch the upper changing plate, the controller initiates the JBC tip change procedure.

The JBC stand and JBC handle usually uses dedicated connector type that is not convenient in my point of view. Yet my version of JBC stand had inproper connection. Perhaps, the stand was designed for other JBC tips C210 or C115. So I have replaced the connectors on the JBC handle and JBC stand with GX12-6 aviation plug.

Use the schematics below to correctly replace the JBC stand connectors.

When the JBC is on-hook (put on the JBC stand) the JBC stand signal connected to the JBC temperature sensor terminal and the controller detects that the JBC iron is not used. As soon as you take the JBC handle off-hook, the controller starts supplying power to the JBC iron.

It is convenient to install optional standby switch and push button. This allows to completely disconnect the JBC iron handle from the controller if you are not going to use in in your soldering session. Or you can use the JBC iron without of JBC stand. Turn the optional switch on to start JBC iron.

The optional push button can be used to start JBC tip change procedure in case you have no JBC stand. Press the tip change button to replace the JBC tip.

The optional switch and button can be placed near the JBC connector and connect to the socket as shon on the pictre above.

Hakko T12 Soldering Tips

The Hakko T12 soldering tips are very convenient tools: they are heating fast and have a sensor inside that allows to keep the temperature very accurate.The tips require three wires only: plus, minus (ground) and earth ground. The heating element inside the tip is connected consequently with the thermo couple allowing to decrease the required wires. It makes the cable very flexible and light weight.

A dedicated handle is required to use the T12 tips. I would like to recommend some handles from KSGER supplier. You can order the variant you like. In any case, you can put the termistor and tilt switch inside the handle.

The thermo-couple installed to the JBC tip generates negative voltage according to the controller ground. And the T12 tip termo-couple generates a positive voltage. To use a single temperature channel inside the controller, we should change the polarity inside the Hakko T12 handle. Usually the handle uses the following color wires:

• Black wire connected to the '-' terminal of the soldering tip.
• Green wire connected to the '+' terminal of the soldering tip.
• Red wire connected to the Earth Ground (body) of the soldering tip.
• White wire connected to the thermistor.
• Blue wire connected to the tilt switch.
• The other side of the tilt switch and thermistor are connected to the Earth Ground (red wire).

First of all the handle should be disassembled and all wires should be desoldered from the handle. Then:

• The tilt switch and the thermistor should be soldered to the '+' terminal of the soldering tip, yet the Black wire should be soldered to the '+' terminal.
• The Green wire should be soldered to the '-' terminal of the tip.
• Red wire should be restored to the Earth Ground (body) of the soldering tip.
• White wire connected to the thermistor.
• Blue wire connected to the tilt switch.

Now the controller will supply the power to the tip in reverse polarity and the thermo-couple will generate the negative voltagea and it would be possible to use the same temperature channel in the controller to manage the Hakko T12 tips.

The picture bellow shows how to connect the Hakko T12 handle to the soldering controller. This type of connection allows to use front connector to use both soldering tip types: JBC or Hakko T12.

Use the following schematics to connnect the hakko T12 handle to the soldering controller. The numbers indicate the pin of the connector.

1. Temperature sensor. Connect pin#1 and pin#5 together inside the 6-wires aviation plug. This allows to read the temperature value from the themo-couple of T12 tip.

2. Ground. Black wire, Connect J9 pin#1 to the '+'terminal of the soldering tip.

3. Earh ground. Red wire. Connect to the Earth ground terminal of the tip.

4. Tilt switch. Blue wire. Connect the J5 pin#2 to the tilt switch in the handle.

5. T12 power. Green wire. Connect J9 pin#2 to the '-' terminal of the soldering tip.

6. Thermistor. White wire (yellow on the picture). Connect the J5 pin#3 to the thermistor in the handle.

Automatic power off feature

This feature increases the safety of the soldering iron. The controller requires TILT or REED switch installed inside the T12 Iron handle. The automatic power off feature enabled as soon as you setup the auto off timeout in the setup menu. You can setup the minutes before the soldering iron will be switched off in case of inactivity.

The TILT switch is working as follows: when it turned downstairs, it is "open" (not conduct the electricity) when it turned upstairs, it is "closed" (start conduct electricity). The tilt switch is the part of the Chinese soldering kit. You can connect the TILT switch in any way, upside down or not, the controller is checking the TILT status change. When the TILT switch status would change, the controller would reset the low power mode timeout.

To use the hardware TILT switch, you must setup automatic power off timeout and standby temperature. If the standby temperature is "OFF" the hardware tilt switch will not be used. Also, you can setup standby time (timeout to switch to low power mode). When the tilt switch enabled, the main working mode changes the following way. The iron is starting heating. When it reaches the preset temperature the "Ready" icon will be displayed and the controller will keep the preset temperature. If the soldering iron is not used (laying on the table, the tilt switch become "inactive") the controller will switch to low power mode. If the iron keep laying for automatic off timeout, the controller will switch off the power completely. As soon as you start using the iron, the controller restores the preset temperature.

Also, you can use REED switch in the soldering handle. The controller would activate the low power mode when the REED switch would "closed". For example, you can place the magnet into soldering station base to activate this switch when you put the soldering handle on the base. Perhaps, you should use mode shorter timeout values when using REED switch.

Hot Air Gun 858D handle

To turn the controller into rework station, you can order hakko 858D hot air gun handle as shown on the picture bellow. This handle is non-expensive and contains all required components: heating element, fan, temperature sensor and reed switch.

When connecting the Hot Air Gun handle to the controller via GX16-8 plug you can use the following reference of the plug pin-out. Unfortunately, I do not know the color of the wires because my handle is completely assembled. I have been told that there is a different kind of hakko 858D handles in the market and your handle can have different pinout. To check your handle pinout you can keep in mind the following criteria:

• The plug should have two wires for the heating element, two wires for the temperature sensor and two wires for the fan. The reed switch shares gnd with a temperature sensor.
• Earth Ground is connected to the metal body of the handle.
• The heating element has resistance about 60 Ohm.
• The thermo-couple (temperature sensor) resistance is about 1-3 ohms.
• The reed switch should be shorten to the groun pin when the handle is near magnet
• The fan should start working when you apply 24 volts to its terminals.

Hot Tweezers

The rework process can be accomplished with hot tweezers. For instance, the some two-leg devices can be desoldered more convenient with the hot tweezers. You can order a Hakko T12 compatible hot tweezers like shown on the picture below.

To use the twezers witch the controller you have to replace the connector together with the cable. The supplied cable has 4 cores only, for our purpose we need 5-core cable like the KSGER Soft 5 Core Silicone Wire For T12 STM32. The tweezers can be dissasembled very easily just remove 3 screws like shown on the picture below.

The tweezers are built on couple of a hakko t12 like tips, connected together in parallel. See picture below.

Each tweezers leg has a 3 connectors: Earth ground (green wire on the picture), "+" (red) and "-" blue. The tilt switch soldered to the blue connector (to "-") by design.

You should change the way the tweesrers connected to the controller. First of all, solder the tilt switch and thermistor (10k NTC) to the "+" termonal of tweezers (red wire on the picture above). Now get another 6-pins aviation plug to connect the hot tweezers to the controller and solder the wires in the following way. Here are the ping numbers of the aviatio plug (see Hakko T12 connector description above).

1. Temperature sensor. Connect pin#1 and pin#5 together inside the 6-wires aviation plug.

2. Ground. Black wire, connect it to the '+'terminal of the tweezers (red wire inside the tweezers on the picture above).

3. Earh ground. Red wire. Connect it to the Earth ground terminal of the tweezers (middle connector, green wire).

4. Tilt switch. Blue wire. Connect it to the tilt switch in the tweezers handle.

5. Tweezoers power. Green wire. Connect it to the '-' terminal of the tweezers (blue wire).

6. Thermistor. White wire. Connect it to the thermistor in the tweezers handle.

Now your tweezers are ready to work. The resistanse between pin 2 and pin 5 (or pin1) should be about 4 Ohms. This is the heater element of the tweezers. The resistance between pin 2 and pin 6 should be 10k - the thermistor resistance.

Note about low-voltage power source

In the previous projects the low-voltage power for MCU and op-amps was supplied by DC-DC converter board based on MP1584 and isolated DC-DC converter b0505. In this project, the MP1584 converter and b0505 are soldered on the main PCB. Nevertheless, in case your power supply have separated 5v power source, you can use the J11 connector on the main PCB to supply the low-voltage power to the MCU and op-amps. The MP1184 IC and complementary components can be skipped in this case. It is recommended to keep the b0505 isolated converter only.

Build/Start checklist

To clarify the sequence for starting the controller here is the list of operations should be performed consequently:

• Build the controller hardware, solder all the components as shown in the complete schematics below.
• Flash the firmware into the controller
• Connect the T12 or JBC soldering iron handle with tip installed to the controller
• Connect the Hot Air Gun
• Power on the controller
• Initialize (format) the SPI FLASH using main memu, then power-cycle the controller. Or you can completely erase the flash using procedure, accessible from about screen. See 'Erase flash' below.
• Connect the controller to your PC using USB cable to the mini-USB port and copy tip_list.txt file to the flash. Also you can copy language files (see the chapter 'Native Language Support' below) if you want. Disconnect the USB cable.
• Activate some tips you are going to use in near future using main menu
• Setup some common parameters through menu (temperature units, automatic power-off timeouts, standby temperature)
• Calibrate Hot Air Gun and several soldering iron tips

Flash firmware to the controller

This project is based on the STM32F103RET6 micro controller. To flash prebuilt firmware to the controller the st-link v2 programmer and ST link utility are required.

Download the STM32 ST-LINK utility from st site. Install the utility in your system. Launch the ST-LINK utility, connect the programmer to the 4pins SWD interface (J1) of the micro controller, press "connect" button. The main window should display the memory content of the micro controller. Press flash button to write the firmaware.

Note: Do not connect AC power the controller while it is connected to the usb programmer. The micro controller oryour computercan be damaged in this case.

Caution:Disconnect AC power from the controller while you connect or disconect soldering Iron handle or Hot Air Gun. Connecting this equipment while the controller is working can damage the controller ports.

Build all the blocks together

On the picture below you can see the block diagram that help you to connect all the parts together.

As you can see, the main AC power after the 5A fuse goes into JP3 socket on the high voltage board. You can connect main power switch to the JP6 socket or short its connectors and completely remove main switch if do not like to use it. JP4 socket on the high-voltage board and J8 socket on the main board are used to connect to the GX16-8 connector of the Hot Air Gun to the controller. The power to the heater goes from JP4 socket and all other wires connected to the J8. Earth ground should be connected to the Earth ground of AC power (not shown here). JP8 on the high-voltage board and J7 on the main board connectors should be connected together. Front soldering Iron GX12-6 connector should be connected to J5 and J9 sockets, rear GX12-6 connector should be connected to J10 and J9. J4 used to connect optional automatic mode switch for Hot Air Gun. Using this switch you can manage the Hot Air Gun without the reed switch. Yet you can turn this switch off and then disconnect the Hot Air Gun completely from the controller when it is not needed. J6 socket on the main PCB should be connected to the J1 connector on the TFT board. This is 14-wires connector to attach the display and rotary encoders. The project code is available on github.

Erase FLASH

The SPI FLASH of the controller should be initialized (formatted) first time controller starts. If the FLASH is not formatted, the controller shows up a dialog menu asking to format the FLASH. After the SPI flash would be formatted, power-cycle the controller. The controller cannot save any file on unfurmatted flash. You can also completely erase the FLASH any time you wish to ensure the FLASH is working properly. It you already calibrate any tip or configured some parameters, you can backup all files from the flash first.

To completely erase flash, go th the main menu, then select 'about' item. Inside about screen long-press the upper encoder to start erasing procedure and configm your choise.

The Debug mode

Debug mode implemented to investigate and fix the problems in the controller hardware. In this mode the controller shows its internal parameters. To reach this mode, select 'About' item in the main menu, then long press the lower encoder.

As you can see from the picture above, the debug screen shows the following information:

• iron power. You can manage the power supplied to the soldering iron by rotating the upper encoder. As the encoder rotated, you adjust the power supplied to the iron. The supplied power will be shown here (in internal units). The more power supplied to the iron the faster it heats. The controller uses the thermistor inside the Hakko T12 handle to determine the type of the soldering iron.
• The currunt through the iron tip. Checking the current through the iron tip the controller detects that the tip is connected. When you remove the iron tip from the handle, the current value should decrease. The value equal to 250 when the tip is not connected and equal to 1500 when the current through the tip detected.
• Iron tip temperature (internal units, 'iTmp')
• The current through the Hot Air Gun fan ('gCur'). The controller checks the current through the fan to ensure the Hot Air Gun is connected. If the current would not detected, the controller never supply the power to the Hot Air Gun heater.
• Irons and Hot Air Gun detection flags ('i-g') in the right bottom corner. If the iron tip is connected, the 'i' flag would be shown. If the current through the fan detected, the 'g' flag would be shown.
• Tilt switch status (open or closed). The value should change when you rotate the T12 iron handle. This status used to check the iron is in use.
• Fan power value (internal units, 'gFan'). Rotate the lower encoder to change this value. If the hot Air Gun activated, the fan should change its rotation speed.
• Hot Air Gun temperature (internal units, 'gTmp'). As soon as the power suppplied to he Hot Air Gun it should heat and the value should increase.
• Timer TIM1 period value in miliseconds.The timer clocked by the AC zero signal. Here the value should be 1000 (or 833 if AC power frequency is 60 Hz in your country). If no AC zero signal detected or the period value is not correct, this line would be shown red.
• The ambient temperature value (internal units, 'amb.'). This is a temperature of the sensor installed into the T12 iron handle. In normal conditions, the value should be near 2000.
• The iron temperature math. dispersion ('iDsp'). This value shows how accurate are readings of the iron temperature. If the dispersion is high, you should check the op-amp U6 installled on the main board.
• The Hot Air Gun temperature math. dispersion ('gDsp'). This value shows how accurate are readings of the Hot Air Gun temperature.

In the debufg mode you can manage the hardware by rotary encoders: upper encoder can manage the soldering iron power, lower encoder can manage the Hot Air Gun fan speed. When you finish hardware checking, long press the lower encoder.

User manual

The Working Modes

The controller supports several modes:

• The main working mode: the controller is ready to work. This mode is activated at controller startup.
• Tip activation mode
• Tip selecting mode
• Tip or Hot Air Gun calibration mode
• Setup menu
• PID tune mode

When the controller is just powered on, the main working mode is activated. In this mode the T12 soldering iron can keep switched off or start running debending on settings in the main menu. You can use soldering iron and Hot Air Gun at the same time

The main display shows the following information:

• The tip name.
• The iron and Hot Air Gun status
• The current temperatures of the iron and Hot Air Gun
• The preset temperature of the iron and Hot Air Gun
• The temperature of the handle (ambient temperature) if the Hakko T12 handle is connected or internal STM32 MCU temperature if JBC tip is connected.
• Iron icon indicating the tilt switch activity
• Fan icon indicating the fan is blowing

As you can see the display shows information of two devices at a time. The rotary encoders manage corresponfing device. The iron is managed by the upper encoder and Hot Air Gun is managed by the lower encoder.

To turn the soldering Hakko T12 Iron on, press the upper encoder. The controller start to heat the Iron to the preset temperature. To turn the Iron off, press he encoder lightly again. When you are rotating the encoder, you are changing the Iron preset temperature.

Long press the upper encoder activates the boost mode. Boost mode can be configured via the main menu. You have to setup the temperature shift and the boost mode duration.

The lower encoder manages the Hot Air Gun. Rotating the encoder you changing the preset temperature or fan speed of the Hot Air Gun. Light-press the encoder to toggle the changing mode between temperature and fan speed. By default, you changing the temperature rotating the encoder. Changing fan speed mode is a temporary mode.

Long-press the lower encoder to activate the main menu. The menu list is looped for convenience. To navigate through the menu, use lower encoder.

Tip activation mode

To start using the tip, you have to activate it first. There are about 150 T12 and JBC tips available in the market at this time. The controller contains about complete list of these tips, but it is too long to select from when you like to change your tip. To short the tip selection list. To add the tip to the selection list, you have to activate it. The tip activation mode started via 'activate tip' menu.

Here you can navigate through the complete tip list using rotary encoder. Selected tips are marked by square checkbox (see T12-KU for instance).To select new tip, navigate to it and lightly press the encoder. If you wish to remove the tip from the selection list, press the encoder button again.

The exclamation mark right to the tip name is indicating that the tip is not calibrated yet. The tip list starts from T12 tips and then shows the JBC tips.

Note: You have to select some tips to start using the controller.

Tip selection mode

The tip selection mode allows you to change the tip you are going to use. You can change the tip to another one from selection list.

To activate the tip selection mode of the Hakko T12, you have to switch the T12 soldering Iron off and disconnect the tip from the tip handle. The controller detects that the tip is not installed in the handle and activates the tip selection procedure. Also the tip selection mode can be activated from the main menu if you are going to use Soldering Tweezors or Hakko 907 iron.

Use the rotary encoder to navigate through the tip selection list and highlight the required tip. Then insert the required tip into the handle. The controller detects the tip is connected and turns to the main working mode. If you are going to activate the Soldering Tweezors or Hakko 907 iron, you should press the lower encoder to select new device.

To activate the tip selection mode of the JBC iron, you have to touch the 'changing plate' of the JBC stand or press optional push button near JBC GX12-6 connector. The controller activates the tip selection procedure. As soon as new tip will be installed into the handle, the controller turns the main working mode.

TheTip Calibration

Note:The external thermocouple required to calibrate the iron tip.

The current tip can be calibrated using 'calibrate tip' menu item. If the tip is not calibrated yet, the "[!]" sign would be displayed near the tip name on the main screen. There are two calibration modes in the current version of the controller firmware: automatic and manual.

In the automatic calibration mode, controller split the temperature interval into 8 reference points. Then it goes through each reference point and tries to keep the temperature as near to calibration point as possible. As soon as the temperature stabilze, the controller requests you to enter real tip temperature. In the calibration mode, the controller uses very conservative PID parameters to prevent overheating of uncalibrated iron tip. It tooks some valuable amount of time to reach and stabilize the reference temperature. The progress bar of green color was added to the calibration screen. This gadget is to brighten up your annoyng minutes of waiting for reaching reference temperature.

To perform calibration procedure more precisely, apply a solder drop to the contact between the thermocouple and the soldering tip rod. To heat-up the soldering tip, rotate the upper encoder and increase the supplied power to the iron. The 'pwr:' label would be displayed on the screen. The value indicating the power supplied to the iron.

Heat-up the tip and apply a solder drop to the contact between the thermocouple and the soldering tip rod then short-press the upper encoder to turn-off the supplied power to the iron. Wait some time before the iron tip cooled then press the lower encoder to start calibration procedure.

The iron starts heating. When the reference temperature reached, the controller beeps and get ready to read the real temperature value. Check the iron temperature by the external thermo-couple and enter this temperature to the controller: rotate the encoder handle to select the real temperature then press the encoder lightly.

Then the controller continues with the next reference point. This procedure finishes when you enter temperature of all 8 reference points or when the real temperature will be greater than maximum temperature. During this procedure controller updates tip calibration data.

After all reference points would be calibrated, the controller saves new tip calibration data to the FLASH. The controller would short beep if the calibration saved successfully.

Caution: In case of emergency you can turn-off the iron power during calibration procedure by pushing the encoder button.Take care of JBC tips and Hot Air Gun, careflly control its temperature during calibration procedure. This equipment can be damaged by overheating.

The red temperature gauge at the bottom of the screen shows the tip temperature in the internal units. The right point of the gauge is the maximum tip temperature (about 450 degrees Celsius). The gause indicating as hot the tip is. If the tip temperature overheats the boundary, the calibration procedure would fail and the controller switches to the main mode. You can cancel the calibration procedure by long-press the upper encoder.

Automatic calibration procedure build the tip calibration by least squares method and the calibration approximation parameters can be inaccurate. To improve the tip calibration data the manual calibration procedure can be used.

In manual tip calibration you must 'guess' the internal temperature readings that matches the calibration temperature.

First, apply a solder drop to the contact between the thermocouple and the soldering tip rod. To heat-up the soldering tip, rotate the upper encoder and increase the supplied power to the iron. The 'pwr:' label would be displayed on the screen. The value indicating the power supplied to the iron.

Short-press the upper encoder to turn-off the supplied power to the iron. Wait some time before the iron tip cooled then press the lower encoder to start calibration procedure.

Here you should select one of the 4 calibration temperature point and press the encoder lightly to start calibration process. This procedure is iterative: you start with the some preset temperature value in internal units (for example, calibrated by automatic procedure) the controller heats the tip to this preset temperature and gets ready. Then you measure the real temperature by the external thermo-couple. If the real temperature is not equal to the preset one, you should increase or decrease the internal preset temperature by rotating the encoder handle.

The progress bar in the lower part of the display shows the difference between preset and current temperature (in internal units) of the tip. The controller keeps the tip temperature near the preset value (vertical line on the progress bar) all the time. To increment the preset temperature, turn the encoder right, to decrease - turn it left.

As soon as the iron reaches required temperature (check the external termo-couple sensor), press the encoder lightly. The controller reads the internal temperature at the moment and saves the calibration point data. Then you return to the preset point selection mode. Here you can select next or previous reference point. When you finish calibration, long press the encoder.

Low power mode

The controller supports low power (standby) mode for Hakko T12 and JBC C245 tips. When the T12 soldering iron is not used for predefined period of time the controller will switch it into low power mode. To enable low power mode, go to the T12 menu, then select 'standby temp' menu item. Press the encoder handle and setup the standby temperature value (or OFF if you do not want to use low power mode). Then select next item, 'standby time' and setup the period to enter low power mode.

Also, you can setup 'auto off' parameter that defines the time the unsused T12 iron should be completely powered off.

When the low power (standby) mode activated, the controller shows the 'standby' icon in the upper-right corner of the display lie shown on the picture below.

As you can see, in this mode, the preset iron temperature will be changed to the snadby temperature. The controller would keep that temperature while the standby mode will be disturbed by using iron or automatic power off timeout.

If you use the iron, the controleer would return to the main working mode, the tilt sensor icon shows that the controller detects the iron was used.

The JBC base stand is used to manage the power supplied to the JBC iron. The Iron would be turned on when you take JBC iron off-hook and turned-off or put into standby mode when you put the JBC on-hook. The JBC menu allow you to configure the standby temperature and standby time duration. In the standby mode, to turn-off the JBC iron completely you can press the upper encoder button.

Tune PID parameters

Note: Perhaps, it is not necessary to tune the PID parameters of soldering iron or Hot Air Gun.

These parameters are determines how fast the iron heats and how accurate the temperature is kept by the controller. You can restore the default values by completely resetting the configuration. Or you can write down old parameter values on some piece of paper and restore them manually via PID tune menu.

The 'tune PID' menu item in the main menu allows tuning PID parameters of soldering iron and Hot Air Gun. When tune PID mode activated, you can see three values of PID parameters on the display, Kp - proportional, Ki - integral, Kd - differential. First, choose the parameter you are going to change and press the encoder button. You turn into tuning test mode. Long press the encoder to start procedure. There are two graphs: the temperature difference and power math dispersion. Both graphs are auto magnifying ones and its maximum value is shown on the Y-axis by the corresponding color.

To power on/off the iron, long press the encoder button. To change the selected parameter, rotate the encoder. On the graph you will see how the temperature changes in time. To select another parameter to change, press encoder lightly. You will return to parameter selection screen. To finish procedure and save new values of PID parameters long press encoder in parameter selection screen.

The firmware

Prebuilt version of the controller software can be downloaded from the github repository. To upload this hex file into controller, you can use stm32 st-link utility.

Native Language Support

The controller supports messages in national languages. The language configuration files are located in the NLS directory in the repository. The main configuration file is cfg.json, where the localization configuration defined. For each language you can find three parameters: language name, message file name and binary font file name. For instance, to configure russian language the following line was added to the cfg.json file:

{ "name": "russian", "messages": "ru_lang.json", "font": "ubuntu_cyr.font"}

The russian messages are described in ru_lang.json configuration file. You can investigate this file if you want. As you can see, standalone messages and menu item messages are defined in this file. The ubuntu_cyr.font is a binary unifont file in u8g2 library format. This font contains ASCII and cyryllic characters.

To simplify adding new language support, the template_lang.json file can be used. Edit this file, adding translation from English to your favorite language then save the template fo a new message file.

My firiend Armindo translated all messages to Portugeese, so the project has Russian and Portugeese languages at least. The binary font ubuntu_we.font contains ASCII and Western Europe characters including Greek symbols. You can use this font for your language if you are speaking on one of the european language. To do this, you have to add new line to cfg.json file and create new message file from template.

When the controller initializes, it searches for cfg.json file on the FLASH. If the file exists, the controller reads this file and checks that it is consistent (for each language entry, the font and message file are exist on the FLASH also). Then the controller loads the configuration where the desired language defined. If the language correctly defined in cfg.json file, it will be activated: binary font and messages will be read from the corresponding files.

Caution: 'language' menu item in the prefference menu can be also translated to the national language. To change the language back, you should be able to understatand the language you select.

To activate the selected language, save the parameters menu.

Upload NLS file to the FLASH

In order to use your native language, the NLS data should be uploaded into SPI FLASH. To do so, you have to conect the main board to your computer via usb cable and copy necessary files to the FLASH.