Analysing the User manual of EMX, on page 11 we can read:
For example, analog channel 3 (ADC3) and the analog output (AOUT) are on
the same pin IO22. Either function can be used but not both of them simultaneously. Visit
Advanced Users section.
However IO22 is mapped on RD CAN Channel 1 Data Receive pin (In).
Should we read IO7 (ADC3 (10Bit Analog to Digital Input) or DAC (Digital to Analog Output)
or Serial port (UART) RXD receive signal (In) for COM4.) instead of IO22?
I just think that’s a typo in the “free text” side of the manual.
should read IO7 in my view. Here’s why; on the next page it shows the table, and:
IO22 is CAN1 input as it’s pin function. It maps to P0.0 on the LPC2478. It can be used as a general Digital IO pin as well.
IO7 on the other hand is shown as ADC3/ DAC/COM4, and maps to P0.26. That means it is ADC3 (10Bit Analog to Digital Input) or DAC (Digital to Analog Output) or Serial port RX (In) for COM4.
So if you’re using CAN, then you should use IO22; if you want ADC/DAC then IO7 seems right.