ADC

Wiren Board has 8-channel ADC which are multiplexed using analog multiplexer into i.mx233 LRADC1 channel.

Main channels

7 channels are exposed to terminal blocks. See Hardware_Overview_rev._2.8#Terminal_blocks for details.

The main channel have 12K/33K dividers. Thus the input voltage for each channel is 1.364 * <measured voltage>

Some of the ADC channels share terminal blocks with FET. Please make sure you have explicitely closed the corresponding FET using GPIO before using ADC.

Input voltage measuring

Channel 5 of the multiplexer is dedicated to measuring input voltage. The channel has 200K/33K divider. Thus the input voltage is 7.061 * <measured voltage>.