MyThermostat | OpenHardware.io - Enables Open Source Hardware Innovation

Features

ATMega328P makes it Arduino compatible.

RFM69 for extended range.

ATSHA204 for hardware signing.

AT25DF512C FOTA programming enabled.

Onboard DS18B20 for temperature protection purposes.

0,96" Oled display.

Linear power supply, so no pitch noise around bedroom.

Power SSR with built-in heatsink. No noise switching.

Uses the original 2x2 keypad for user interaction.

The board is exactly the same form factor as the factory one so it can be mounted without modifying the original frame. Just unplug the old board and drop-in the new one. The goal is to keep heater modifications as low as possible.

Source:	/home/gerar/PCBs/MyHeater/radiador.sch
AE1	Connector Hirose U.FL
C1	100nF
C2	1500uF
C3	100nF
C4	100nF
C5	10uF
C6	100nF
C7	100nF
C8	100nF
C9	100nF
C10	100nF
C11	100nF
C12	4700uF
C13	100nF
D1	Diotec ABS8
F1	Schurter UMT250
HS1	Fischer SK104
J1	Pin header
J2	Pin header
J3	Faston 250
J4	Faston 250
J5	Faston 250
J6	Pin header
J7	Pin header
J8	Pin header
JP1	Normally closed jumper
JP2	Normally closed jumper
Q1	BC817
R1	150
R2	330
R3	56k
R4	10k
R5	0
R6	10k
R7	4k7
RV1	Varistor
TR1	Hahn BVEI3052878
U1	Crydom SPF240D25
U2	DS18B20Z
U3	RFM69HCW
U4	LF33
U5	AT25xxx
U6	ATSHA204A
U7	ATmega328P-AU
Y1	CSTCE

Name	Size	# Downloads
MyThermostat-B.Cu.gbl	79.07 kB	355
MyThermostat-B.Mask.gbs	64.41 kB	358
MyThermostat-B.Paste.gbp	7.77 kB	364
MyThermostat-B.SilkS.gbo	6.49 kB	367
MyThermostat-Edge.Cuts.gm1	1.59 kB	323
MyThermostat-F.Cu.gtl	123.17 kB	369
MyThermostat-F.Mask.gts	89.95 kB	325
MyThermostat-F.Paste.gtp	59.31 kB	357
MyThermostat-F.SilkS.gto	67.41 kB	343
MyThermostat-NPTH.drl	124 B	374
MyThermostat-PTH.drl	1.37 kB	350
MyThermostat-SCH.pdf	103.47 kB	322

Name	Size	# Downloads
MyThermostat.ino	8.13 kB	425
BoardSetup.ino	2.12 kB	399

Gerator commented 6 years ago
@kimot I am not handling that situation. I'm taking for granted ssr will do his job. Maybe there's some ssr safety topic I'm unaware? Suggestions for a v3.0 are welcome.

About the temperature measuring... I use two sensors. The one in the board protects electronics from temperatures beyond design (60°C). It's near the ssr because the ssr's derating curve is the most limiting condition.
The control sensor is placed in the bottom of the heater. It connects to the board through a 3 pin header connector.
kimot commented 6 years ago
How do you solve a situation where a SSR breakdown occurs and you are hunderts km away from home?
I think some classic relay is necessary in this application to handle error conditions.
Similarly, measuring the temperature in the blast near SSR is not very accurate.
Gerator commented 6 years ago
Thanks. It would be nice!
alowhum commented 6 years ago
Whoa, what an amazing job! You should send a pic to the original manufacturer, perhaps they'd enjoy seeing your conversion.

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