HeaterMeter 4.2 Hardware

Bryan Mayland edited this page Apr 29, 2017 · 48 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.

Standard HeaterMeter hardware is built on a HeaterMeter v4.2 PCB


HeaterMeter can be built either as a standalone or for integration with a Raspberry Pi. The only difference between the two is the population of the Pi socket JP1. Both configurations provide automatic grill control, and LCD display. Set Point, manual fan mode, probe offsets, open lid detect and max fan speed configurable via buttons. The standalone requires initial configuration via serial commands. There is integrated no web access or graphs in standalone mode, but there is a serial status output to allow you to roll your own solution.

Quick and Easy: Mouser parts. Does not include thermocouple or DigiKey-only parts 1xBlower 1xSocket 4xJacks. Alternatively, HeaterMeter kits are available from the HeaterMeter store which include all the Mouser and Digikey parts as well as a PCB.

Main Board

Qty Value Device Parts Link
1 0 R-US_0204 R7 (wire)
4 390 R-US_0204 R2, R10, R12, R15 Mouser DigiKey
1 680 R-US_0204 R8 Mouser DigiKey
3 1k R-US_0204 R1, R3, R21 Mouser DigiKey
2 2k2 R-US_0204 R9, R14 Mouser DigiKey
1 4k7 R-US_0204 R11 Mouser DigiKey
1 10k R-US_0204 R20 (use 10k 1% below)
5 100k R-US_0204 R19, R22, R23, R28, R29 Mouser DigiKey
1 68k R-US_0204 R13 Mouser DigiKey
1 22k R-US_0204 R4 Mouser DigiKey
9 0.1u C-US025-025X050 C1, C2, C3, C7, C10, C15, C16, C17, C18 Mouser DigiKey
1 1N4001 DIODE-DO41-7 D3 Mouser DigiKey
1 1N5819 DIODE-DO41-7 D2 Mouser Mouser Alt DigiKey
4 BS170 BS170 Q1, Q2, Q4, Q5 Mouser DigiKey
1 MCP1700-33 MCP1700-33 IC4 Mouser DigiKey
1 FQU11P06TU MOSFET-P Q3 Mouser DigiKey
1 74HC595N 74LS595N IC3 Mouser DigiKey
1 DIP28 DIP28 IC2-SOCK Mouser DigiKey
1 Pi PINHD-2X13 JP1 DigiKey (alt DigiKey) (alt Mouser)
1 ALARM SPEAKER/AL11P SP1 Mouser DigiKey
1 OKI-78SR-5 OKI-78SR-05H IC1 Mouser DigiKey
1 16MHz RESONATOR-PTH Y1 Mouser DigiKey
4 10k 1% R-US_0204 R5, R16, R17, R18 Mouser DigiKey
1 220u INDUCTOR L1 Mouser MouserAlt
2 100u/10 CPOL-USE2.5-5 C5, C6 Mouser DigiKey
1 47u/25 CPOL-USE2.5-5 C12 Mouser DigiKey
1 100u/25 CPOL-USE2.5-6 C4 Mouser DigiKey
1 PINHD PINHD J1 (LCD), J2 (PROBE), J7 (ISCP), J8 (FTDI) Mouser
1 10k TRIM_US-CT6 R6 Mouser DigiKey
1 LCD PINHD-1X16 J1 Mouser Gray/Amber LCD Color Gallery
1 TACTILE-4 TACTILE-4 S1 OnlineComponents (UK Alt RSComponents)
1 ATmega328P AVR-MEGA8-PPTH IC2 Mouser DigiKey Mouser Non-P
3 GRN LED3MM LED1, LED2, LED3 (any ~3mm LED, any colors you want) MouserR MouserY MouserG MouserGAlt

Power Probe, Blower, and Servo Connectors

These are the "built in" connectors, there is space on the PCB for them. External connectors can be used for probes by attaching to the J2 pin header.

Qty Value Device Parts Link
1 POW POWER_JACKPTH J9 Mouser MouserAlt
1 RJ45-8 RJ45-8 JP2 Mouser DigiKey
1-4 Probes AUDIO-MONO JP3, JP4, JP5, JP6 MouserDigiKey

Power, Probes and Blower

Qty Description Link
1 12VDC/1A power brick 5.5x2.1mm barrel jack USPlug EUPlug
1 Blower-style fan 12VDC 5-10CFM DigiKey60mm DigiKey50mm DifferentBlower
1-4 Thermistor Probes -- ThermoWorks Pro-Series (Std or Needle) / Maverick ET-72/ET-73 (3ft or High Heat) HeaterMeter Probes

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.

Optional Parts

Qty Value Device Parts Link Reason
1 Ambient THERMISTOR_R-2,5 TR1 Mouser Only if you want an onboard 'ambient' temperature sensor

Thermocouple Support

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
2 1n (1000 pF) C-USC0805 C8, C11 Mouser
1 10n (0.01 uF) C-USC0805 C9 Mouser
1 0.1u C-USC0805 C13 Mouser
2 10k R-US_R0805 R25, R26 Mouser
1 1k R-US_R0805 R24 Mouser
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