AnsweredAssumed Answered

Stm32f407 DIsovery ADC Issue

Question asked by fasial.muhammad on Oct 16, 2013
Latest reply on Oct 16, 2013 by Clive One
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.
 

Attachments

Outcomes