Problem with STM32F107 and I2C1

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jsavonet
Posts: 6
Joined: Fri Mar 01, 2019 10:00 am
Location: France, Lyon

Problem with STM32F107 and I2C1

Postby jsavonet » Fri Mar 15, 2019 2:30 pm

Hi all,

I'm currently facing an issue with I2C1 on an OLIMEX P107 board.

I first try the example provided and I2C1 on remapped pin PB8/PB9 is working just fine.
Configuration is like this in the board.h file:

Code: Select all

/*
 * Port B setup:
 * PB8  - Alternate O.D.    (I2C1 SCL, remapped).
 * PB9  - Alternate O.D.    (I2C1 SDA, remapped).
 */
#define VAL_GPIOBCRL            0x88844480      /*  PB7...PB0 */
#define VAL_GPIOBCRH            0x38BBB8FF      /* PB15...PB8 */
#define VAL_GPIOBODR            0xFFFFFFFF


Now moving the issue I'm facing. I would like to use I2C1 on pin PB6/PB7 (alternate default) since my own design is using those pins.
So I change the board.h file to this:

Code: Select all

/*
 * Port B setup:
 * PB6  - Alternate O.D.    (I2C1 SCL).
 * PB7  - Alternate O.D.    (I2C1 SDA).
 */
#define VAL_GPIOBCRL            0xEE844480      /*  PB7...PB0 */
#define VAL_GPIOBCRH            0x38BBB888      /* PB15...PB8 */
#define VAL_GPIOBODR            0xFFFFFFFF


Code is running on the board but can get any clock signal on the scope.
If someone as an hint It would be great,

Thank in advance,

Jeremy

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Giovanni
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Re: Problem with STM32F107 and I2C1

Postby Giovanni » Fri Mar 15, 2019 2:33 pm

Hi,

1) Make sure to remove the alternate from the previous pins.
2) Have you activated the remap?

Giovanni

jsavonet
Posts: 6
Joined: Fri Mar 01, 2019 10:00 am
Location: France, Lyon

Re: Problem with STM32F107 and I2C1

Postby jsavonet » Fri Mar 15, 2019 2:42 pm

Hi Giovanni,

Thank you for the quick reply.

1) How to remove the alternate from the previous pin.
Is setting PB8/PB9 as input in the board.h file is ok

Code: Select all

/*
 * Port B setup:
 * PB6  - Alternate O.D.    (I2C1 SCL).
 * PB7  - Alternate O.D.    (I2C1 SDA).
 */
#define VAL_GPIOBCRL            0xEE844480      /*  PB7...PB0 */
#define VAL_GPIOBCRH            0x38BBB8[b]88[/b]      /* PB15...PB8 */


2) How I can activate/deactivate the remap feature ?

Thank you,

jsavonet
Posts: 6
Joined: Fri Mar 01, 2019 10:00 am
Location: France, Lyon

Re: Problem with STM32F107 and I2C1

Postby jsavonet » Fri Mar 15, 2019 3:18 pm

I also removed in board.c the remap feature on I2C1 ( AFIO_MAPR_I2C1_REMAP ) but still no clock signal on the scope.

Code: Select all

AFIO->MAPR |= AFIO_MAPR_USART3_REMAP_FULLREMAP |
               AFIO_MAPR_SPI3_REMAP;

jsavonet
Posts: 6
Joined: Fri Mar 01, 2019 10:00 am
Location: France, Lyon

Re: Problem with STM32F107 and I2C1 [SOLVED]

Postby jsavonet » Fri Mar 15, 2019 3:30 pm

Problem solved.
The configuration need to be:

Code: Select all

#define VAL_GPIOBCRL            0xBB844480      /*  PB7...PB0 */


Alternate push-pull output for PB6/PB7 and deactivate remap in board.c

Thanks again for the support Giovanni


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