Skip to content

HeaterMeter 4.3 Hardware

Bryan Mayland edited this page Oct 29, 2021 · 31 revisions

As a reminder, HeaterMeter refers to the ATmega (Arduino) based microcontroller board that runs the LCD, reads button and temperature probe inputs, and controls the servo and blower motor. This document describes the configurations and design of the HeaterMeter board, which may optionally be attached to a Raspberry Pi. This list is split into three sections

  • Main HeaterMeter Board which contains the input power and probe connections, as well as the blower and servo output.
  • LCD and Button Board which contains the drive circuitry for the 16x2 character LCD and buttons, as well as the 3 indicator LEDs. Optional if a local display and buttons are not desired.
  • Thermocouple Addon, which are components added onto the Main Board to utilize a thermocouple control probe instead of the thermistor. The FOODx probes remain as thermistors. Optional

Quick and Easy: Mouser base parts and LCD/button parts (does not include thermocouple parts below). Alternatively, HeaterMeter kits are available from the HeaterMeter store which include all relevant parts as well as PCBs.

Main Board

Qty Value Device Parts Link
3 1k R-US_0204/7 R1, R3, R21 Mouser DigiKey
1 2k2 R-US_0204/7 R14 Mouser DigiKey
5 10k 1% R-US_0207/7 R5, R16, R17, R18, R20 Mouser DigiKey
1 22k R-US_0204/7 R4 Mouser DigiKey
1 68k R-US_0204/7 R13 Mouser DigiKey
5 100k R-US_0204/7 R19, R22, R23, R28, R29 Mouser DigiKey
8 0.1u C-US025-025X050 C1, C2, C3, C7, C15, C16, C17, C18 Mouser DigiKey
1 100u/25 CPOL-USE2.5-6 C4 Mouser MouserAlt DigiKey
2 100u/10 CPOL-USE2.5-5 C5, C6 Mouser DigiKey
1 47u/25 CPOL-USE2.5-5 C12 Mouser DigiKey
1 16MHz RESONATOR-PTH Y1 Mouser DigiKey
2 1N5819 1N5819 D2, D3 Mouser Mouser Alt DigiKey
1 220u INDUCTOR9MM L1 Mouser MouserAlt
1 ALARM SPEAKER/AL11P SP1 Mouser DigiKey
3 BS170 BS170 Q1, Q2, Q5 Mouser DigiKey
1 FQU11P06TU MOSFET-P Q3 Mouser DigiKey
1 OKI-78SR-5 OKI-78SR-05H IC1 Mouser DigiKey
1 ATmega328P AVR-MEGA8-PPTH IC2 Mouser DigiKey MouserNon-P
1 MCP1700-33 MCP1700-33 IC4 Mouser DigiKey
3-4 PROBES AUDIO-MONO JP3, JP4, JP5, JP6 v4.3.5 Mouser v4.3.5 DigiKey v4.3.6 Mouser
1 POW POWERJACKPTH J9 Mouser MouserAlt
1 RJ45-8 RJ45-8 JP2 Mouser DigiKey
1 DIP28 DIP28 IC2-SOCK Mouser DigiKey (Optional)
1 RPi PINHD-2X13 J1 Mouser DigiKey Mouser2 DigiKey2 DigiKey3 (MouserWorseAlt DigiKeyWorseAlt)

LCD and Button Board

Qty Value Device Parts Link
2 220 R-US_0204/7 R12, R15 Mouser DigiKey
1 1k R-US_0204/7 R10 See above
1 1k2 R-US_0204/7 R8 Mouser
1 1k8 R-US_0204/7 R11 Mouser
1 3k9 R-US_0204/7 R2 Mouser
1 8k2 R-US_0204/7 R9 Mouser MouserAlt
1 10k POTENTIOMETER R6 Mouser DigiKey
1 0.1u C-US025-025X050 C10 See above
1 74HC595N 74HC595N IC3 Mouser DigiKey
1 BS170 BS170 Q4 See above
1 LCD, LCD1M, LCD2M PINHD-1X16, 1X5 M J1, JP1, JP8 Mouser
2 LCD1F, LCD2F PINHD-1X5 F JP1, JP8 Mouser
4 BUTTONS TACTILE-12MM S1, S2, S3, S4 Mouser
1 RED,YEL,GRN LED3MM LED1, LED2, LED3 (any ~3mm LED, any colors you want) MouserR MouserY MouserG MouserGAlt

Thermocouple Addon to Main PCB

Thermocouple support relies on surface mount soldering an 8 pin 3mm x 3mm chip and some 0805 passive components. Any 'ole capacitors (20%/16V) and resistors (10%/0.125W) will do fine. Mouser Project (does not include jack J4). If this is your first surface mount soldering experience, I recommend getting a couple extra of the cheap parts because they are easy to lose or destroy during soldering and you don't want to have to place another order for a 6 cent part.

Qty Value Device Parts Link
1 AD849X AD849X IC5 Mouser
1 1k R-US_R0805 R24 Mouser
2 10k R-US_R0805 R25, R26 Mouser
1 10n (0.01 uF) C-USC0805 C9 Mouser
2 1n (1000 pF) C-USC0805 C8, C11 Mouser
1 0.1u C-USC0805 C13 Mouser

Power, Probes and Blower

Qty Description Link
1 12VDC/1A power brick 5.5x2.1mm barrel jack MouserUSPlugDigiKeyUSPlug EUPlug
1 Blower-style fan 12VDC 5-10CFM Mouser DigiKey50mm DifferentBlower
1-4 Thermistor Probes -- ThermoWorks Pro-Series (Std or Needle) / Maverick ET-72/ET-73 (3ft or High Heat) Amazon-T-Std Amazon-T-Needle Amazon-M-3ft Amazon-M-High

A word about 12V power adapters - It is highly recommended to get a name brand power supply. A good quality 1A supply can drive a Raspberry Pi 3, Wifi, Servo Damper, and up to a 500mA blower without breaking a sweat. Generic no-name power supplies that can be found on Amazon or eBay might cost half as much but some 1A supplies aren't even capable of providing enough power to power up the Pi and HeaterMeter and will reboot endlessly, on servo movements, or when enabling the blower. In addition, these cheap supplies can lack the noise suppression circuitry which can affect HeaterMeter readings or protection components which can make them unsafe in fault conditions. If purchasing an generic supply it is recommended to use a 2A supply at a minimum to be confident that HeaterMeter will work at all.

4.3 PCB Revisions

  • 4.3.3 - Initial release
  • 4.3.4 - Larger annular rings, chamfered corners, better labels
  • 4.3.5 - Conversion to KiCad, replace power and probe jack holes with slots
  • 4.3.6 - Replace probe jacks with CUI MJ1-2503A (were MJ-2508N), thermocouple holes with slots
Clone this wiki locally