https://www.marcelpost.com/wiki/index.php?action=history&feed=atom&title=Mcu_0139-remote-433MHz-transmitter 2026-05-17T04:22:53Z Revision history for this page on the wiki MediaWiki 1.39.17 https://www.marcelpost.com/wiki/index.php?title=Mcu_0139-remote-433MHz-transmitter&diff=3616&oldid=prev 2023-03-23T23:12:12Z

<p></p> <p><b>New page</b></p><div>Home automation project sending telemetry using a low-cost ISM-band (433MHz) transmitter.<br /> <br /> <br /> This is a change of plan from what I originally intended to use (the RFM69HW modules), but with several home automation solutions easily available I decided to make use of these modules instead.<br /> <br /> <br /> This is the bare transmitter module.<br /> <br /> [[File:H34A-module.jpg]]<br /> <br /> <br /> <br /> <br /> Here is the transmitter module wrapped in heatshrink and stuck on top of an Arduino Nano<br /> <br /> [[File:0139 Prototype-1 Arduino-nano.jpg]]<br /> <br /> <br /> <br /> Making the overall form factor even smaller by contemplating putting it on a Digispark board.<br /> <br /> [[File:0139 Prototype-2 Digispark ATtiny85.jpg]]<br /> <br /> The benefit is that the ATtiny85 modules are fairly cheap and can hold up to 8kB of program memory. A quarter the size of the ATMega328 Arduino but probably still more than enough to send some telemetry.<br /> <br /> <br /> <br /> This is the module fitted onto a custom PCB that has the ATtiny85 on the underside.<br /> <br /> [[File:0139 Prototype-3 Attiny V1.0.jpg]]<br /> <br /> <br /> <br /> Final result on top of a 3D printer battery holder<br /> <br /> [[File:18650-T85-telemetry.jpg]]<br /> <br /> <br /> <br /> Schematic: <br /> <br /> [[File:0139 PCB v1.5 schematic.png]]<br /> <br /> <br /> Gerbers: [[File:0139-remote-sensors-433Mhz v1.4 gerbers.zip]]<br /> <br /> Source code: [[File:0139 remote 433MHz transmitter v0.6.ino.zip]]<br /> <br /> <br /> <br /> &lt;pre&gt;<br /> 0139 remote sensors 433mhz transmitter bill of materials -- PCB v1.5<br /> <br /> R1 1206 22k<br /> R2 1206 4k7<br /> R3 1206 1k<br /> R4 1206 100k<br /> R5 1206 100k<br /> R6 1206 4k7<br /> <br /> C1 1206 1uF<br /> C2 1206 1uF<br /> C3 1206 100nF<br /> C4 1206 10nuF<br /> <br /> U1 SOIC ATTiny85-20SH<br /> U2 TO-92 DS18B20 <br /> U3 TSOT23-5 NCP718ASN330T1G<br /> <br /> T1 SOT23 (N-Ch FET) BSS138 or Si2302DS<br /> T2 SOT23 (P-Ch FET) NDS352AP or BSH203<br /> T3 SOT23 (P-Ch FET) NDS352AP or BSH203<br /> <br /> D1 1206 LED<br /> <br /> H34A-433 ASK transmitter 433MHz 2.6-12V<br /> &lt;/pre&gt;</div>

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