Hello,can someone tell me why RN-42 have analog inputs when they are not usable I mean is it possible to pass analog data threw those pins and how can I activate them ?
I will guess that by RN-42 you mean a Bluetooth module.
Maybe this one: http://www.parallax.com/product/30086
Perhaps you could tell us the one you are using? Perhaps you could show one that actually has analog inputs?
Well in that datasheet you can clearlly see the analog: https://www.sparkfun.com/datasheets/Wireless/Bluetooth/rn-42-ds.pdf Pin - 30 and 35 it says analog input default: not used :)
I think you should solder yourself up a board and use them if you would like.
They by default are not used my question is how to enable them I already soldered the chip on a PCB :)
Well in that datasheet you can clearly see the scematic that has them hooked up to VCHRG and VBATT.
My guess is the analog inputs are used for something like voice communication, which a module like this isn't really built to do. But I dunno.
Yes, in that data sheet both analog inputs are connected using voltage dividers, so I'm pretty sure they are used to measure battery (VBATT) and charging (VCHRG) voltage level. I think they can be accessed somehow If you wanna do some research here is the most up to date data sheet http://ww1.microchip.com/downloads/en/DeviceDoc/rn-42-ds-v2.32r.pdf Curiously that typical application circuit has been changed an now theese analog inputs are not used
I found this thread while I was trying to figure out how to use those inputs as well. Eventually I gave up, but then I figured this out by accident. So I figured I'd come back and share the knowledge.
You can read the ADC values by going into CMD mode, and running the commands "A1" or "A2" These commands are not listed in the documentation, and they don't appear in the help on the device, and I could not find it anywhere on the internet at all. I discovered it by luck, it turns out you can enter the letter "A" followed by ANYTHING, and it will return the value of ADC1, it didn't take long to test A1 and A2 and found the value for ADC2 also. Anyway, run those and you'll get a response back that looks something like this:
ADC1=15, 21 mv ADC2=22, 34 mv
Those are the values returned while the pins are floating, I don't actually have anything connected to them at the moment.