I have been working on using some humidity sensor boards that I have as part of the node. The sensor boards contain a HS1101 relative humidity sensor (variable capacitance) connected in a circuit with a 555 timer which outputs a frequency based on the value. It is the same 555 timer circuit found in the HS1101LF datasheet on page 3. Originally I planned on doing the calculations by converting the equations for use with fixed-point math for speed, but instead decided to use a lookup table of values because I was lazy, and I think that may be actually faster than doing the calculations in software. Here is a picture of the prototype connected to the humidity sensor board.
Here is the output of values I am receiving from the wireless node. The serial output is from a Launchpad running my little testing RX energia sketch which parses the incoming data from the node.
code can be found in my other github repo here:
https://github.com/emdarcher/msp430-nrf24l01-testing/tree/master/sensor_comm/send_temp_RH
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