Environment Controller

I am looking for a coder to write a program for my Rasp Pi. SUMMARY: Write a program that calculates VPD ([login to view URL]) and when the resulting calculation is not within range of the user specified number, the software will send signals to relays to turn on a heater/AC or humidifier/dehumidifier. DETAILS: Your software will essentially be using data from 3 sensors: - Sensor that collects Relative Humidity (RH percentage) of a room - Sensor that collects Ambient temperature of a room - Sensor that collects temperature located near plant leaf With data from the above sensors, a calculation shall be made that results in a VPD number. These calculations are very well known and can easily be found online (1 example see wiki link above). Once this VPD number is calculated, the software will send a signal to turn on/off the proper device to change the VPD number to a user desired input. For the more visual coders, here is a VPD Chart [login to view URL] We want the software to turn on or off devices to keep things in the green zone. To be completely honest, I bet a good Googler could already find complete or partially complete code for this. I have some code that I can share if needed but would prefer it to be coded from scratch. I am open to negotiate price. From what I understand this should be fairly easy and only a few hours worth of work. But if my impressions are wrong things can be negotiated. I see a few similar jobs on frelancer websites asking for $40 which seems very low-ball to me. If any of this sounds interesting to you, please PM me. If you need any further clarification or sources on how the calculation is done, PM me. If you feel like your skills are best suited to ONLY calculate the VPD from given data then I can hire you and find another coder to finish off the rest.