Ted Toal
Published

Build a Beutler SmartVent Custom Thermostat

New controller broke your Beutler SmartVent? Make a SmartVent thermostat! Or use this as a starting point for building any old thermostat!

IntermediateFull instructions provided5 days413
Build a Beutler SmartVent Custom Thermostat

Things used in this project

Hardware components

Cable containing five 20-gauge solid copper wires with colored insulation, long enough to run from your EcoJay controller through the walls to the SmartVent thermostat.
You can get this at a local hardware store.
×1
AZ-Touch MKR 2 Wall Mount Touchscreen Set
I had to order it from Europe and it took a couple weeks to arrive.
×1
Arduino Nano 33 IoT with headers
ABX00032, also available on Amazon.
×1
Grayhill 78H01
One small DPST slide switch that will fit within the case.
×1
Fuseholder Pc Fuse Clip 5Mm Front Leads Gm Series 10
Just need two little clips to hold a small glass fuse. Another option: Magic&shell Fuse Clip 30PCS Brass Plated Tin Fuse Holder Clip for 5x20 mm Glass Ceramic Tube Quick Fuse on Amazon.
×2
Fuse GMA Fast Acting 0.25A (250mA) 250V 5mm x 20mm
0.2A fuse is even better. Another option: 300 Pcs 15 Values 5 x 20mm Fast-Blow Glass Fuse Assortment, 250V 0.1A/ 0.25A/ 0.2A/ 0.5A/ 1A/ 1.5A/ 2A/ 3A/ 4A/ 5A/ 8A/ 10A/ 12A/ 15A/ 20A Tube Fuses, on Amazon. Get more than one, you may blow some of these out.
×1
Omron Electronic Components LLC G5V-1-DC5 Relay
×1
Transistor PN2222 General Purpose NPN 30 Volt 0.6 Amp
PN2222 NPN transistor often comes in Arduino starter kits. Many different NPN transistors will work fine, used as a switch to drive the Omron G5V-1 relay coil.
×1
Diode 1N4001 50 Volt 1 Amp
Most any diode will work, used across relay coil to suppress transients when relay turns off.
×1
TDK Corporation EPCOS B57862S103F thermistor
Any decent NTC thermistor with about 10K resistance at 25C is good. Often a thermistor comes with an Arduino starter kit, and this is probably fine. I provide Python code to find coefficients for different thermistors. Best if you have the data sheet for the thermistor you choose.
×1
Panasonic ERZ-V07D560 varistor
Act as protector on 24VAC power input and 24VAC output to EcoJay vent control
×2
Zener Diode 1N4734A 5.6V 5% 1W
Act as protectors on the outside sensor inputs and 5V supply.
×3
LTL-307E 5mm red LED
Just need two small LEDS of two different colors
×1
LTL-307Y 5mm yellow LED
Just need two small LEDS of two different colors
×1
10K ohm Resistor 1/2w (0.5Watt) ±1% Tolerance Metal Film Fixed Resistor
Such as EDGELEC 100pcs 10K ohm Resistor 1/2w (0.5Watt) ±1% Tolerance Metal Film Fixed Resistor, on Amazon. Only 3 resistors needed. Require 1% tolerance for accurate temperature measurement.
×3
Various 1/4W resistors, 2.2K, 5K, 10K
Schematic calls for 2.2K, 5K, 10K, but required value may vary in order to get LED brightness to desired level. It is good to have a variety of resistors on hand, such as come in Arduino starter kits. Example: ALLECIN 25 Values 1/4W Resistor Kit from 1 Ohm to 1M Ohm 1/4 Watt 1% Metal Film Resistors Assortment, on Amazon.
×3
0.1 uF 100 Volt Mylar Capacitor
Bypass capacitors are good to have on hand. Another option: mxuteuk 120 Pcs 0.1uF 104 100nF Multilayer Monolithic Ceramic Capacitor 5.08mm 0.1uf-104, on Amazon.
×4
Jonard Tools R-30B-0050 Blue Insulated Kynar Copper Wire Roll, 30 AWG, 50 ft Length
Any wire-wrap gauge of wire will work, as long as it has high resistance to melting of insulation, as Kynar does.
×1
40PCS (20Pairs) 8PIN Female and Male Connecting Plug with Terminal Connector Wire Cable for Light Strip 150mm Compatible with JST SM
Only one pair of this connector is needed, but it comes in packs of 20 pairs. Or, find a similar type of connector with at least 5 wires.
×1
Heat shrink tubing of different sizes such as Ginsco 580 pieces 6 colors
I bought a heat shrink tubing kit described as Ginsco 580 pcs 2:1 Heat Shrink Tubing Kit 6 Colors 11 Sizes Assorted Sleeving Tube Wrap Cable Wire Kit for DIY.
×1

Software apps and online services

Arduino IDE
Arduino IDE
KiCad
KiCad
This is an excellent open-source PCB design program that lets you draw schematics and design PCBs. You don't need this for this project, but I provide KiCad files for the custom thermostat circuitry in case you want to open them in KiCad and perhaps make some changes to them.

Hand tools and fabrication machines

Computer that can run the Arduino IDE, with a spare USB port
Soldering iron (generic)
Soldering iron (generic)
You want to be able to solder small items spaced 1/10 inch apart easily. I used both a small and medium soldering iron.
Solder Wire, 0.028" Diameter
Solder Wire, 0.028" Diameter
Desoldering Pump, Metal
Desoldering Pump, Metal
Mastech MS8217 Autorange Digital Multimeter
Digilent Mastech MS8217 Autorange Digital Multimeter
Any digital multimeter that will measure A/C and DC voltage, resistance, and has a continuity-testing mode will work.
Wire Stripper & Cutter, 26-14 AWG Solid & Stranded Wires
Wire Stripper & Cutter, 26-14 AWG Solid & Stranded Wires
Wire Stripper / Cutter, Full Flush
Wire Stripper / Cutter, Full Flush
You should have a wire cutter that will cut flush to the PCB. A tool like this might serve as a 30-gauge wire stripper, general wire cutter, and flush cutter.
Eclipse Tools CP-301G Pro
Here is another wire stripper that will work. You would like it to work extremely well. This one was ok, though not fantastic.
Plier, Needle Nose
Plier, Needle Nose
Multitool, Screwdriver
Multitool, Screwdriver
Micro USB cable with data lines
Everybody has micro USB cables lying around, but many of those lack data lines and are for charging only. These will fail to allow the Arduino IDE to connect to the microcomputer. I found only one of my 8 cables had data lines in it.

Story

Read more

Custom parts and enclosures

Custom SmartVent Thermostat User Manual

This is the user manual for the thermostat.

AZ-Touch MKR Rev B features document

Shows what the AZ-Touch MKR is and what comes with it

AZ-Touch MKR Rev B Assembly Instructions

Assembly instructions if you buy an unassembled AZ-Touch MKR 2

Arduino Nano 33 IoT datasheet

Datasheet for the Nano 33 IoT

Excel spreadsheet of pin correspondences on Nano/MKR/SAMD21G

Pin names change going from microcontroller to microcomputer to AZ-Touch MKR, this spreadsheet shows the name correspondences

OMRON G5V-1 Relay datasheet

Datasheet for OMRON G5V-1 relay

PN2222 NPN Transistor Datasheet

Datasheet for PN2222 NPN Transistor

Varistor datasheet

Datasheet for recommended varistor

1N4001-D diode datasheet

1N4734A datasheet for zener diode

Small DPST switch

Schematics

SmartVent Thermostat Schematic V4

PDF file of schematic for SmartVent thermostat.

AZ-Touch MKR schematic V02-02

PDF of AZ-Touch MKR 2 schematic

Arduino Nano 33 IoT schematic

PDF of Arduino Nano 33 IoT schematic

Excel spreadsheet of SmartVent thermostat wiring and component layout

The component positioning and the wiring of the thermostat components in the AZ-Touch MKR prototype area is shown in these spreadsheet sheets

Code

SmartVent Thermostat GitHub Repository

Go to this repository and use the red CODE button to download the zip file containing all files for the SmartVent thermostat. Unzip them and put the folder in a convenient place. Copy the folder named "SmartVentThermostat" inside the "programs" folder to your Arduino programs folder (the folder where all the .ino program file folders are located; mine is at Documents/Arduino/programs). Look through the documents folder and check out the files there to see what they are so you are aware of their existence. My SmartVent Custom Thermostat project on hackster.io describes how to build this custom specialized thermostat. The code in this repository is needed. Other libraries must be installed, see hackster.io instructions. The files in the documents folder are also referred to by those instructions. Note: this repository contains all the schematic and CAD files that are ALSO located in the SmartVent Thermostat project on hackster.io.

Credits

Ted Toal
2 projects • 4 followers
1975 BS Elect Eng/Comp Sci 1976-2009 embedded systems software eng 2015 PhD Genetics/Genomics 2016-22 cancer research scientist Retire 2022
Contact

Comments

Please log in or sign up to comment.