Materials Required
Digital Oscilloscope: FNIRISI 138 Pro
PCBWAY GIFTSHOP
DESIGN
POWER MODULE ASSEMBLY
FINAL ASSEMBLY
RESULT
TESTING
CONCLUSION

Published August 27, 2024 © MIT

BOXcilloscope

An open source easy to make portable oscilloscope with an in-built battery.

BeginnerProtip1 hour484

Things used in this project

Hardware components

PCBWay Custom PCB

Software apps and online services

Autodesk Fusion

Hand tools and fabrication machines

3D Printer (generic)

Story

Greetings to everyone, and welcome back.

This is BOXcilloscope, a homemade portable oscilloscope that runs completely on battery power, making it portable and simple to carry around.

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Here, we are utilizing the FNIRISI 138 PRO, a compact, portable digital oscilloscope made for both professionals and enthusiasts.

The idea was to create a scope that resembles a box, is incredibly portable, and has a built-in battery pack to operate the device.

The name BOXcilloscope is a play on words, as we have designed the scope to look like a small box.

We used Fusion360 to create and build the model, and we 3D printed the parts using gray and transparent PLA.

Inside the device, there is a power module that uses four parallel lithium-ion cells to boost the voltage of the cells from 3.7V to 5V and generate a steady 3A current. Furthermore, PCBWAY provided the oscilloscope and power module for this project.

This article is about the complete build process of this project so let's get started with the build.

Materials Required

These were the materials used in this project.

Digital Oscilloscope FNIRISI 138 PRO
POWER MODULE
3D-printed components
Li-ion Cells
Push-button-rocker switch Style
M2 Screws

Digital Oscilloscope: FNIRISI 138 Pro

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The oscilloscope is an electronic test instrument that graphically displays varying voltages of one or more signals as a function of time. It’s a crucial tool for debugging, analyzing, and characterizing electrical signals.

Purchasing a high-quality oscilloscope is an expensive endeavor.

For basic testing, I got the FNIRISI-138 Pro, a portable, handheld digital oscilloscope meant for both enthusiasts and pros, rather than shelling out a fortune for an oscilloscope that I would use maybe once or twice every six months. It has a 200 kHz bandwidth and a real-time sampling rate of 2.5 MSa/s.

Waveforms can be easily viewed on this device's 2.4-inch high-definition LCD screen. It is capable of measuring voltages up to ±400V and supports many trigger settings (single, normal, and automatic).

Additionally, it includes an efficient one-key AUTO function for quick waveform display without complex adjustments.

Technical Specifications-

Operating Voltage: 5-6V
Sampling Rate: 2.5MS/s
Bandwidth: 200kHz
Vertical Sensitivity: 10mV/Div-20V/Div (in 1-2-5 increments)
Horizontal Time Base Range: 10µs/Div-20V/Div (in 1-2-5 increments)
Voltage Range: X1 Probe ±40V, X10 Probe ±400V
Trigger Modes: Auto/Normal/Single
Coupling Mode: AC/DC
PWM Output: 3.3V, F.R:0~80kHz, Duty Cycle: 0~100%
Show: 2.4 in/PPI:320*240
Size: 66*71.6*22.8mm
Weight: 53g

PCBWAY GIFTSHOP

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As for sourcing this Handheld oscilloscope, we got it from PCBWAY's Giftshop.

https://www.pcbway.com/project/gifts_detail/FNIR138PRO_Handheld_Small_Portable_Digital_Oscilloscope_4533d963.html

PCBWAY gift shop is an online marketplace where you can get a variety of electronics modules and boards for their genuine price, or you could use the PCBWAY currency, which is called beans.

You get beans after ordering something from PCBWAY as reward points, or you can also get them by posting any project in the PCBWAY community.

They are presently celebrating their tenth anniversary in business by hosting a tour that includes a few activities in which you can take part and win some goodies, such as special coupons and the chance to open blind boxes filled with merchandise from their gift shop.

Over the past ten years, PCBWay has distinguished itself by providing outstanding PCB manufacturing and assembly services, becoming a trusted partner for countless engineers and designers worldwide.

Their commitment to quality and customer satisfaction has been unwavering, leading to significant growth and expansion.

You guys can check out PCBWAY If you want great PCB service at an affordable rate.

DESIGN

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In order to design this project, the oscilloscope needs to first be modeled. All necessary components, such as the power module and rocker switch, have to be imported into the model.

The prepared model was made up of two primary parts: the main body that holds the scope in place, along with the side rocker switch, and the power module. The second part covers the model's back side and is called the lid.

We created the model so that the topmost PCB layer of the oscilloscope would be added on the front side, and the body would be sandwiched between the first and second layers of the oscilloscope. This way, we can easily mount the scope in place using the four M3 bolts with the PCB standoffs. The oscilloscope is made up of three PCB layers joined together using PCB standoffs.

Four M2 screws are used to mount the power module inside the main body.

On the left side of the main body, we have positioned the rocker switch and given an opening for it to be fixed.

Furthermore, we have a nametag that reads "BOXCILLOSCOPE" on the front; we plan to 3D print it using two colors of filament. We accomplish this by changing the filament color and stopping the print in the middle, but a multi-filament printer can make this process simple.

Once the model is finished, we export all the files and 3D print every component using a 0.6mm nozzle and 0.2mm layer height. The main body was made of transparent PLA, whereas the lid was made of grey PLA. The nametag was also printed on white PLA in addition to grey.

POWER MODULE ASSEMBLY

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Prior to starting the assembly of the power module, we unscrewed the M3 bolts to access the scope's backside PCB.
The battery connectors are located here, and we can supply 5V to 9V to power this device. We soldered connecting wires to the battery's CON2 connector, which is subsequently linked to the 5V and GND terminals of the power module.
Next, we added the scope's backside PCB in its place.
When the power module's push button is pressed, the scope turns on, indicating that the setup is working.

FINAL ASSEMBLY

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The final phase in the assembling process is to remove the scope's top layer, which is fastened in place by four M3 bolts.
After that, we align the mounting holes on the scope with the mounting holes on the main body by positioning the assembly scope inside the body.
After aligning the top layer of the scope with the body's mounting holes, we place the top layer on the front side of the main body and fasten it securely to the M3 bolts.
The push button, which resemble a rocker switch, is then pushed into the designated slot on the left side of the main body.
Next, we linked the push button terminals on the power module to the push button terminals on the buttons; these two buttons will be wired in parallel.
After positioning the power module within the main body, we fasten it inside with four M2 screws.
After that, the lid part is positioned on the back and fastened using M2 screws.
Next, we attached the nametag to the front side of the screen by first gluing the nametag to the surface and then moving it into position.

the Assembly is complete.

RESULT

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The result is a compact, portable, BOX-shaped oscilloscope with an inbuilt battery that we can use to examine any electronic component or device.

The device turns ON when the rocker switch is pressed for one second, and OFF when it is pressed for three seconds.

TESTING

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For testing the BOXcilloscope, we started out by connecting the 10X Probe to the Oscilloscope's BNC Port.

Next, we utilize a simple Raspberry Pi PICO setup with an LED connecting to GPIO0 and GND. In this setup, we connected the probe's negative lead to PICO's GND and its tip to GPIO0.

Here, we have added a FADE sketch into the PICO, In the Fade sketch LED brightness is gradually increase and decreased using Pulse Width Modulation.

The analogWrite() function sets the duty cycle of the PWM signal. A value of 0 corresponds to a 0% duty cycle (LED off), and a value of 255 corresponds to a 100% duty cycle (LED fully on).

We can see the duty cycle change in the BOXcilloscope, which ranges from 0% to 100%. This occurs at a linear pace and quite quickly.

The signal's wave shape is also being observed.

CONCLUSION

Although there are some lower frequency stability and accuracy errors, overall, this is a useful device that is best suited for beginners or hobbyists who want to start with electronics. The quality of the included 10X probe is not up to par with good 10X probes offered by brands like Tektronix or HANTEK. In addition, we notice increased phase noise, which can cause issues in delicate applications like communication systems.

Aside from the nitpicks, this is a helpful tool for beginners.

Overall, this project was a success and needs no further revisions.

In addition, we appreciate PCBWAY's support of this project. Visit them for a variety of PCB-related services,, such as stencil and PCB assembly services, as well as 3D printing services.

Thanks for reaching this far and I will be back with a new project pretty soon.

Peace.

Code

Fade

int led = 0;         // the PWM pin the LED is attached to
int brightness = 0;  // how bright the LED is
int fadeAmount = 5;  // how many points to fade the LED by

// the setup routine runs once when you press reset:
void setup() {
  // declare pin 9 to be an output:
  pinMode(led, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  // set the brightness of pin 9:
  analogWrite(led, brightness);

  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;

  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  // wait for 30 milliseconds to see the dimming effect
  delay(30);
}