This PR is preliminary ground work for FMUv5.
PX4 does not use the NuttX adc driver. But used the same format
for the data returned by the nuttx ADC driver.
There was a fixme:in src/platforms/px4_adc.h "this needs to be
a px4_adc_msg_s type" With this PR the need for
src/platforms/px4_adc.h goes away as the driver drv_adc.h now
describes the px4_adc_msg_t.
- Other channels are irrelevant since they aren't physically
connected. Avoid the I2C transaction to get invalid data
- Port the driver to use only one address, as it should be
- Minor changes here and there
- Add test() method to read the latest value - helpful during
debugging.
Measure the battery voltage of Aero RTF kit will be done by FPGA
and read by AeroFC using I2C bus.
The protocol is a little bit odd, it have different I2C slave
address for each "register", in future the FPGA RTL will
have a protocol more similar to other I2C sensors.
Also Aero RTF don't have a ADC line to measure current consumption.