Mraa_aio_* on radxa-zero?


I saw that there are two pins (15 and 26) on radxa-zero v1.51 which are supposed to be adc’s. I tried to read from pin 15 with something like this (ubuntu on radxa-zero v1.51):

printf("%u adc inputs available\n", mraa_get_aio_count());
mraa_aio_context voltage = mraa_aio_init(0);
int value = mraa_aio_read(voltage);

But the reading for value is returning -1 (error). Also, the inputs available is printing 0.

My question is: should the analog inputs be supported by libmraa on radxa-zero v1.51? Please note that digital gpio is working properly with libmraa, I am now only having problems with analog input.

Any tips, please?

Thank you.