I have a few setups where I use multichannel relays to control 220V. It is always a pain to connect all the commons in serial. Does anyone know of a product that does this? Else I might just try my hand at a PCB to do this.
@eiten I haven't yet made any progress on finding a good VOC sensor, but along the way I did find out something interesting regarding CO2: namely, if you sleep with your bedroom door closed at night, then the odds are good that the CO2 levels rise to surprisingly high and unhealthy levels.
The better CO2 sensors are factory calibrated and never again need recalibration for the life of the sensor (usually around 10 years or so), because they are used in HVAC systems to control fresh air intake to guarantee indoor air quality. As a for instance, here is one such CO2 sensor: https://www.digikey.com/en/products/detail/senseair/006-0-0008/15790694 At around $50 for just the sensor element itself, it's not exactly cheap, but then again, I'd say it's worth it, because who wants to be burdened by remembering to calibrate their CO2 sensors?
Ideally, I'd like to find a sensitive VOC sensor that also will never require calibration.
Nearly all, and maybe all, of the off-the-shelf IAQ montoring stuff that you might buy for, say, $300 or less seems to require periodic calibration. For that reason, this might be one of those occasions where build is rather than buy.
I am new in this forum and I have a question regarding mysensors and iobroker. I did not work with mysensors up to now. Since some weeks I use iobroker installed on a raspberrypi.
Now I want to integrate my 433 Mhz doorbell in iobroker. I know, that there is an adapter for mysensors in iobroker. My question is: Is it possible to get a notification in iobroker if someone is pressing the button on my doorbell? As I understood, I have to connect the receiver to an arduino nano and connect the arduino to my rasberrypi on which iobroker is running.
I bought the Every because it implied it was backward compatible with the nano. No, it's not, as we found out.
Be that as it may, any word on a getting the Every working with mySensors?
https://github.com/sandeepmistry/arduino-nRF5
Install this and find libraries for whatever sensors you have on that board.
@basaksts said in nRF5 Multi Sensor Board (12-14€):
Also I need an bootloader
No, you really don't. You need ST-Link, or J-Link SWD programmer/debugger. Connect it to SWDIO, SWCLK, 3.3V and GND and program it using Arduino IDE.
It's an awfully convoluted way of doing things but suspect your error lies in misunderstanding calculations mixing ints and floats and something screwy with your resistor bridge - It is always worth checking the bridge with a multimeter and raw voltage to verify the expectation.
If you have 3v at the top of your voltage divider, you should be getting 0.9593v applied on the ADC pin which will be read as 892 against the 1.1v internal reference.
The easiest way I found was to define a multiplier needed to derive the raw voltage, in this case (((R1+R2)x1.1)/R2) - For your resistor arrangement the max you can read is 3.4404v before exceeding the 1.1v internal reference.
To reverse the ADC reading of 892 to raw voltage is (892x3.4404)/1023 = 2.9984 v.
Perhaps this is a simpler way to do it
float MULTIPLIER= (((1000+470)*1.1)/470);//Resistor bridge values in k and Vref
int sensorValue = analogRead(BATTERY_SENSE_PIN);
float batteryV = (sensorValue * MULTIPLIER)/1023.0; //Note the trailing decimal point on the 1023 for calculations involving floats
