Need help wiring a sensor to the Particle Boron

I want to connect an Apogee 111-SS to the Boron but am unsure of the best way to wire it up. The 111-SS is an Infrared Radiometer and outputs serial data. It should work with the power requirements, but the grounds are what I’m confused by. Any help is appreciated, thanks!

View the 111 product manual here.

@boron, this sensor does not output serial data! The sensor has a thermopile output and a built-in thermistor, both of which must be read to calculate the infrared level. Both are analog outputs and an accurate 2.5v excitation voltage must be applied for both the thermopile and the thermistor. In addition the thermopile can output both negative and positive voltages so it cannot be read by the Boron ADC directly (it must be offset).

Apogee’s SI 4xx series units do output SDI-12 serial data but that protocol uses half-duplex communications which is something the Boron does not support in hardware (it does not support 7bits, Even parity, 1 stop bit mode). I have seen interrupt-based Arduino libraries that implement SDI-12 using “bit-banging” (aka software) but none have been ported to Particle.

Thank you for catching that. I am not very experienced with this stuff. It sounds like it would not be feasible to use Apogee’s sensors with a particle board. I want to stick with this platform because of its cloud capabilities. Do you know of any alternative sensors? DFRobot makes some but they’re much less precise than Apogee.


How easily could I get the 4xx running on an Arduino? I could just use TX RX to transmit the data onto the Boron. I have extra Arduinos on hand and need the Boron for thermocouple data anyways.

May I suggest you search for an Arduino library that implements that?
Then you can assess the effort and decide upon the work in front of you.


Thanks, I found a good tutorial/library to make this work. The question still stands, can I use the TX/RX ports on the Boron to receive data from the Arduino for cellular transmission? At that point, I’m using it as a cellular modem because of the low cost. If it works it works though.

@boron, it may still be possible to do software SDI12 on the Boron but if you add an Arduino then, yes they will be able to communicate ONLY if the UART of the Arduino is not used for SDI12. Otherwise they could communicate using I2C.