Quick Capacitive Sensor question
- Thread starter artswan
- Start date
I would expect that would depend on how you were powering the PICAXE. No problem I know of from battery power, but there are all sorts of right and wrong ways of powering a PICAXE from the mains. Can you show us a schematic or data on the power supply you expect to use?
Also, what is the nature of the environment the humidity sensor would be in? Meaning, what's the proposed application?
Also, what is the nature of the environment the humidity sensor would be in? Meaning, what's the proposed application?
fernando_g
Senior Member
artswan:
your idea sound intriguing...yeah, make a little experiment and see what happens.
However, you may need a calibrated temeprature/humidity sensor alongside when you are doing that to compare and correlate the ADC values with actual %RH readings.
I know for instance, that most humidity sensors have a substantial temperature coefficient, which must be used to correct the raw reading. Additionally, the results most likely would be non-linear, and you will require a lookup table to convert them to meaningful %RH values.
Lastly, I suspect that the capacitive readings could also have some supply voltage dependency, just like a normal ADC readings. As such, I would ensure when you perform the experiments that the supply voltage is accurate and recorded...of course the best would be to use a variable supply to adjust it to exactly +5.00 volts and eliminate that variable.
All in all, this can be a very nice experiment to perform. Even though the conclusion could be that the idea is not useable, you will have practiced and learned a lot of new concepts.
Have it a go!
your idea sound intriguing...yeah, make a little experiment and see what happens.
However, you may need a calibrated temeprature/humidity sensor alongside when you are doing that to compare and correlate the ADC values with actual %RH readings.
I know for instance, that most humidity sensors have a substantial temperature coefficient, which must be used to correct the raw reading. Additionally, the results most likely would be non-linear, and you will require a lookup table to convert them to meaningful %RH values.
Lastly, I suspect that the capacitive readings could also have some supply voltage dependency, just like a normal ADC readings. As such, I would ensure when you perform the experiments that the supply voltage is accurate and recorded...of course the best would be to use a variable supply to adjust it to exactly +5.00 volts and eliminate that variable.
All in all, this can be a very nice experiment to perform. Even though the conclusion could be that the idea is not useable, you will have practiced and learned a lot of new concepts.
Have it a go!
FWIW- in 2009 Wayne Geary & I explored the HopeRF HH10D sensor, & persuaded even a 08M to read it.