Stm32f407 DIsovery ADC Issue

[ffaisaldj]

Posted on October 16, 2013 at 15:00

Hi,

I have a relay circuit which has fourteen relay output (i.e 14 devices can be switched on or off from this) , I have attached the circuit for a single output. I am sending command to switch on the related output through the GPIO of a STM32 f4 discovery  board . I am reading 14 channels of ADC1 in scan mode with multi channel configuration to get the power consumption through each output I am Using following ADC pins for getting the data. PA0 PA1 PA2 PA3 PA4 PA5 PA7 PB0 PB1 PC0 PC1 PC2 PC4 PC5 My first problem is that I am constantly getting value on PC0 (even though there is no load) because it is internally connected to the temerature sensor..How Can I disable this connection of internal temperature sensor so that I can use this pin as a channel of ADC. Second problem is that at PA5 and PA7 I am also getting the voltage level without applying any load... I have detached my board with discovery and check the pins individually and I saw that PA5 and PA7 are producing constantly around 2.5 Volt ...why.. with regards, Muhammad Faisal.   #stm32f4-disovery

[Tesla DeLorean]

Posted on October 16, 2013 at 15:36

The manual for the STM32F4-Discovery would illustrate why pins wouldn't be useable. PA5,6,7 are attached to the LIS302DL

You'd have to remove parts or cuts traces to free up the pins. That or buy a break-out board that is free of all this other circuitry.