STM32f051C6 PF6/7 AF for I2C

[jgnoss]

Posted on February 26, 2013 at 07:38

Hello, I try to make I2C on PF6/7 on the STM32F051C6  (48 Pin device) working.

To get what AF to use, Ref man points to the datasheet. But the datasheet is not clear to me, it has a AF Table for PortA and PortB and  Table 13 Pin definitions  says PIN 35 - - PF6 I/O FT I2C2_SCL PIN 36 - - PF7 I/O FT I2C2_SDA I tried AF0 and AF1 but the chip let me in the dark. The code I have is working on the STM32F0-discovery with I2C1 on PB6/7. Any ideas? Ju #i2c-stm32f051c6

[Tesla DeLorean]

Posted on February 26, 2013 at 16:10

I tried AF0 and AF1 but the chip let me in the dark.

The chip only supports GPIOx_AFRL/H on ports A and B so doing anything of port F would be impossible/inadvisable. Just set the pins in AF mode, and don't change the PinSource muxing. Set the pins as OD, and use external pull-ups.

[jgnoss]

Posted on February 26, 2013 at 16:57

clive1 you are my hero.

I got it working on the discovery. Now I have to make it work on my PCB. No big deal I guess. But can you tell me where you got this info from, that GPIOx_AFRL/H only works on Port A and B. Or is this just interpretation because of missing AF table to other ports? Ju

[Tesla DeLorean]

Posted on February 26, 2013 at 17:24

But can you tell me where you got this info from, that GPIOx_AFRL/H only works on Port A and B.

It's marked in a couple of places in the reference manual in terms of scoping when the registers are valid.

[jgnoss]

Posted on February 26, 2013 at 18:00 OK, got it. We never stop learning. thanks a lot to you clive1

[Nickname925_O]

Posted on November 22, 2013 at 16:41

Ho gnoss,

please, can you share your I2C code for STM32F0? Thanks a lot in advance, Peppe.