Hi
I'm using the STM32F4 discovery board and the Embest expansion board for the use of SD card/serial port etc.
The problem I have is my ADC values float by up to 100 bits when the discovery board is plugged into the expansion board, they are fine when the discovery board is stand alone.
I've tried using two ADC's, one with the discovery board 3V connected to one ADC to get a correction factor, but the pins float by different amounts.
I then decided to bend the two ADC pins back so they don't physically connect to the expansion board, this causes the permanent 3V ADC reading to be steady at 0xFFF but anything below 3V still floats?
Just wondered if anyone had come across this?
cheers
Discovery board
http://uk.farnell.com/stmicroelectronics/stm32f4discovery/stm32f407-usb-otg-discovery-kit/dp/2009276
Expansion board