@kimot in theory you might be right, but in practice... it just works. The propability of collisions is extremely low and this is, as far as I know, the only problem you can worry about. After all, it was not my idea to use MySensors with RS485: https://www.mysensors.org/build/rs485

Hello, I'm thinking about upgrading this board to include pinout for LIS3DH breakout board, like this one : https://www.aliexpress.com/item/LIS3DH-Three-Converters-Motion-Accelerometer-Triaxial-Acceleration-Temperature-Sensor-Module-Development-Board-Replace-ADXL345/32840326778.html and ditch the ADXL shield as it's not a good solution, it has either the ADXL345 which uses too much power, or the ADXL362 which is ultra low power but lacks advanced functionality like tap/double tap detection. I would like to have feedback of users on this (do it sound useful ?), and also know if anyone uses the SMD footprints on the board, for leds and for reserve capacitors, as it could be a cleaner board without those footprints. I would make the following changes : put footprint for LIS3DH accelerometer along the "NModule connector" as it has too many pins to put elsewhere keep only one I2C footprint on the side, for "GY-49" MAX44009 light sensor breakout board: https://www.aliexpress.com/item/GY-49-MAX44009-Ambient-Light-Sensor-Module-for-Arduino-with-4P-Pin-Header-Module/32828654450.html temperature/humidity would be via the existing "SMD" footprint, it's not through hole but very easy to solder as it's 2.54mm pad spacing remove SMD footprints for LED, add footprint for through hole reserve capacitor, keep SMD footprints for reserve capacitors only if I have space for them shield would be a bit extended to go over the 2 M2 holes in the "power" part of the NModule, so it could be fitted with spacers and nylon screws and have stable/reliable mechanical connection between NModule and Shield. Basically this would be the footprint of the shield : [image: 1527422033742-c8e52cd0-47fe-4a5e-b6a3-554e216603cc-image.png] So in the end it would make one shield to have Temperature/Humidity/Light/Acceleration or Temperature/Humidity/Light/Door.

Thanks gohan.. This forum is a great source of inspiration. Lots of examples of people and their own projects, and/or problems they encounter(ed). I'm fairly new to MySensors & Arduino, but i have a lot of experience with Atmel AVR. At this time, i'm more reading than writing: absorbing info first. Hopefully i can help out others too sometimes.. it's cool to share knowledge. I already have 10 Arduino Yúns & 2 Raspberries at my disposal (they belong to friends i'm helping out). It would be fun to find a sensible application to combine a MySensors radio network (or perhaps multiple networks), and the IOT-capabilities of the Yún(s) & Raspberries. But that's another project..

Yes. Correct. call BME.begin() every time and the subroutine only at the beginning. And you are also correct about the library. I use the "blue" lib, from Sparkfun. As i can recall correct (it's been over a year since I built the damn thing) I have tried both, and found the Sparkfun more stable. And you CAN switch off power for this module, but after conversion it goes to sleep and uses less than 1uA. Hardly worth the effort, because the current can find a way over the data lines, and that's a pain in the behind to solve (I tried!).

I see a lot of "!TSF" and "NACK" which seems to be radio communication problems. That's MySensors related and can be related to many things, from soldering problem to power / capacitor issues. In MY_DEBUG mode you should see your temp/hum printed on serial every ~15s so there is something wrong there, either wiring or a code issue. Ty with the example included with the library "i2c_SI7021.h", without any MySensors related stuff, to see if your sensor is detected. You should see temp/hum on the serial.

@kristof-delaere The terms that you refer to are footprint/package specifications (size, shape). Here are links to the above components on digikey: CMOS SMD (oscillator) http://www.digikey.com/product-detail/en/epson/SG7050CAN-27.000000M-TJGA3/SER3999CT-ND/5175091 0207W (120 ohm resistor) http://www.digikey.com/product-detail/en/tt-electronics-welwyn/WRM0207C-120RFI/985-1466-1-ND/3648019 0207W (2.7k ohm resistor) http://www.digikey.com/product-detail/en/yageo/MCP100JR-2K7/MCP100JR-2K7-ND/2169183

The choice of MOSFET can be tricky. Seems that irlz44n was discontinued so you may need to find one adapted to the voltage and current you want to handle. In all the cases you need to get a logic MOSFET too, meaning that they are fully open usually around 1 to 3V. Also I'm sort of confused as it seems to me that L7812CV is a Voltage regulator, not a MOSFET. So if you are actually using that in the MOSFET spot it will definitively not work. Especially if you are handling high current or voltage I would recommend using one from a reputable source for your MOSFET, I recently switched from mouser / digikey / aliexpress to mostly use http://www.arrow.com as you get free regular shipping, event if you order a couple of components (no affiliation to them whatsoever).

@tlustoch The node is a very simple one. So I never considered boot loaders, as the node would not need changing sketches during it's lifetime. I have boot loading functionality on my other designs, this one is a minimal board. Any extra chip would beat the purpose of the word "minimal". It's a dumb node for a reason :-)