Next logic step is flipping polarity like here: http://gardenbot.org/howTo/soilMoisture/

My communication problems vanished by exchanging the amplified version by a normal NRF24.

Hi,

I built a 1m x 1,5m accoustic absorber with Basotect for the ceiling in my living room. To generate ambient lighting, I installed a non-smart analog 5m LED strip on the top side. My first attempt was to use PWM from arduino which resultet in visual steps when do slow fading. Next approcach was a 12bit PWM motor shield, resulting in 4096 steps which were smooth but I couldn't use the real good FastLED library. So I ended up with a P9813 RGB MosFET Board from ebay which represents a single pixel. (But can easily chained for several strips in the room.) FastLED is dithering between the 256 steps of the arduino and produces very smooth transitions.

Hardware:

• Arduino Nano (~5€)
• NRF24L01 (~2€)
• P9813 RGB MosFet Board from ebay (Full Color RGB LED Strip Driver Sensor v1.1 for Arduino STM32 AVR P9813) (4,29€)
• LM2596S DC-DC Step-Down Converter for 12V->5V (~1€)
• 5m RGB LED Strip ( < 10€)
• old 12V laptop power supply

Software:

My setup is a mqttClientGateway and a raspi with node-red.
To change color, you can send a RRGGBB string to mysensors-in/node-id/0/1/0/40
To change the fade time you can send a integer from 0 to 255 to mysensors-in/node-id/1/1/0/24
To persist the current settings to eeprom you can send a "1" (meaning bool "true") to mysensors-in/node-id/2/1/0/2
To set the brightness you can send 0 to 100 (V_PERCENTAGE) to mysensors-in/node-id/3/1/0/3

https://github.com/rollercontainer/nanoP9813FastLEDMySensors/blob/master/main.cpp

This code is working. Nevertheless it could be a lot better. It is posted, to help people take code lines or inspirations out of it. I think, I change the setup to esp8266 because of the OTA flash ability.

Greetings

New Full Color RGB LED Strip Driver Module Shield for Arduino STM32 AVR V1.0

$2.09

299 available

5Stks LM2596S DC-DC Step-Down Schaltregler Schalt Netzteil Wandler Konverter

$3.87

131 available

searched a bit and found that @ceech already made a harvester with a coin cell.

http://www.ebay.de/itm/BQ25570-thermal-solar-energy-harvester-/332071662285

still too big and too expensive in comparison with dozens of alkaline batteries which will run for years, but that is the way to go sometime.

BQ25570 thermal / solar energy harvester

$18.20

110 available

Did you considered a tiny solar cell like enocean does?
https://www.enocean.com/en/enocean_modules/stm-320/
That would be perfect...

Maybe its better to measure the voltage every 10 or 100 loops and only send one custom message/alert when its dropped below a threshold. I am using the MQTTClientGateway and Node-Red. In case of a battery-low message, node-red could send me an email with the node name. I will give it a try...

From https://www.mysensors.org/download/serial_api_20:

V_TEXT          47 	Text message to display on LCD or controller device 	S_INFO
V_CUSTOM 	48 	Custom messages used for controller/inter node specific commands, preferably using S_CUSTOM device type. 	S_CUSTOM```

Just noticed, that I use another login at home. So, the Tim-Abels is the rollercontainer... Sorry for that.

@AWI one step forward, two steps back... Thanks for the hint.

I guess, I should send battery percentage every 10 interrupts or so. Even if the contact doesn't trigger for a while, I can force it by showing my neighbours my ocd on doors ^^ (knock, knock, knock - Penny!)

What do you think?

Maybe there is something like a counter (variable++) which causes a overflow after two month?

@AWI said in My Slim 2AA Battery Node:

@rollercontainer Your sleep looks good. Did you remove this piece of code?

// Activate internal pull-ups
	digitalWrite(PRIMARY_BUTTON_PIN, HIGH);
	digitalWrite(SECONDARY_BUTTON_PIN, HIGH);

Take a look at this thread for a < 1 uA consumption...

Hmm, I noticed, that I have to disable the internal pullups. But instead of removing the lines, I set them to LOW. I will test it without the lines and come back. Thank you @AWI.