ADS1115 only 15bit at differential measurement
Moderators: adafruit_support_bill, adafruit

Forum rules
Talk about Adafruit Raspberry Pi® accessories! Please do not ask for Linux support, this is for Adafruit products only! For Raspberry Pi help please visit: http://www.raspberrypi.org/phpBB3/

ADS1115 only 15bit at differential measurement

by tim123 on Tue Jan 01, 2013 2:38 pm

The Adafruits_ADS1x15.py works in Single-ended mode fine for me (after some modifications), but in differential mode I should get 16bit instead of 15 to get results also for negative values.

The script contains to interesting lines:
Code: Select all | TOGGLE FULL SIZE
    result = self.i2c.readList(self.__ADS1015_REG_POINTER_CONVERT, 2)
...
    return ( (result[0] << 8) | (result[1] & 0xFF) )

result[0] delivers only values from 128 to 255.

Thanks

P.S.: I'm very happy with my ADC on the raspi.
tim123
 
Posts: 2
Joined: Tue Jan 01, 2013 1:50 pm

Re: ADS1115 only 15bit at differential measurement

by tim123 on Sat Jan 19, 2013 6:12 pm

Sorry error was on my side. Now it works fine. Makes fun to play with small signals from strain gauges.
tim123
 
Posts: 2
Joined: Tue Jan 01, 2013 1:50 pm