@bko, Provided a fix for the extra zero in the converted data by:
1)Changing the DMA mode from “circular” to "normal"
2)Enabling ADC2 external trigger conversion for each analogRead
3)Reset the buffer and DMA counter before starting the ADC-DMA command
Commt : https://github.com/spark/core-firmware/commit/b7ce24a4fb2dfe4f90e597e3a0f568f9ae098cfe