STM32F207 - I2C error - No clock after start condition & ack failure AF after first call to SendData

tilman · ‎2011-06-09

Posted on June 09, 2011 at 12:59

Hi,

i am using the code below to try to communicate with a I2C sensor. I have a STM32F207VG with the corresponding peripheral lib v1.0, both lines have 4k7 pull-ups.

The problem has 2 aspects:

- there is no clock signal on the SCL after the start condition

- the acknowledge failure AF is set after the first call to I2C_SendData

I don't know which one is the cause and which one is the consequence, but that AF is certainly nothing which has to do with its �real� purpose, as no data has yet been transmitted, what acknowledge should have failed?

&sharpdefine I2C1_PORT GPIOB

&sharpdefine I2C1_SCL_PIN GPIO_Pin_8

&sharpdefine I2C1_SDA_PIN GPIO_Pin_9

GPIO_InitTypeDef GPIO_InitStructure;

I2C_InitTypeDef I2C_InitStructure;

/* ----Setup phase---- */

/* Enable I2C1 and I2C1_PORT & Alternate Function clocks */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

/* Reset I2C1 IP */

RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, ENABLE);

/* Release reset signal of I2C1 IP */

RCC_APB1PeriphResetCmd(RCC_APB1Periph_I2C1, DISABLE);

/* I2C1 SCL and SDA pins configuration */

GPIO_InitStructure.GPIO_Pin = I2C1_SCL_PIN;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(I2C1_PORT, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = I2C1_SDA_PIN;

GPIO_Init(I2C1_PORT, &GPIO_InitStructure);

/* Alternate function

remapping

*/

GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_I2C1);

GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1);

/* I2C

De

-initialize to clean */

I2C_DeInit(I2C1);

/* I2C configuration */

I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;

I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;

I2C_InitStructure.I2C_OwnAddress1 = 0x00;

I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;

I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

I2C_InitStructure.I2C_ClockSpeed = 400000;

/* I2C Initialize */

I2C_Init(I2C1, &I2C_InitStructure);

/* I2C ENABLE */

I2C_Cmd(I2C1, ENABLE);

/*----- Transmission Phase -----*/

/* Wait if the bus is busy */

while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

/* Send START condition */

I2C_GenerateSTART(I2C1, ENABLE);

/* Test on EV5 and clear it */

while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

/* Send sensor address */

I2C_SendData(I2C1,0xF1);

It is step by step register readout that makes me think that the problem is the first call to I2C_SendData. Up to there, all registers show what they should, but as soon as this call takes place, the register SR1 signals the AF. The data register is filled with the correct address but the AF disables the peripheral, the data will not be transmitted. I already tried to do some sw_rst, I2C_ClearITPendingFlags, re-enable peripheral or generate a second start condition � all useless.

On the scope one can see that after the initialization, both lines go high as they should. Then, after about 5(ms), SDA goes down for about a tenth of a ms before returning to high. At the same time, SCL also ''tries'' to go down, but it doesn't even arrive at 0V level before it's pulled high again. I suppose the MCU attempts to generate the start condition here, but should'nt there be a delay between the SDA and SCL transitions? Afterwards, both lines stay high forever and that's it...

Any ideas? Help would really be appreceated!

Don TseTse

#problem-with-i2c #stm32f-i2c #i2c #stm32f

zhangmei · ‎2011-12-11

Posted on December 12, 2011 at 07:34

Hi,

The problem you talked about already exsits in STM32F1xx series MCUs. There is a new method to solve the problem for STM32F2xx series MCUs. You can use DMA to transfer the I2C data. I have done it well on

http://www.armkits.com/product/devkit1asp

board. I enclose the software example for your reference.

________________

Attachments :

main_c.txt : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0qT&d=%2Fa%2F0X0000000beL%2Ffhk3Hj_fqY2b0AfIGWW8MWiYsHjRd_rYzPWa2CGrc.Q&asPdf=false

stm322xg_eval_c.txt : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0oJ&d=%2Fa%2F0X0000000beK%2Ff1to88W2mF0WFpxwaUsr5PpWQlRHvi1.giqxe.WqvfI&asPdf=false

stm322xg_eval_h.txt : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0QJ&d=%2Fa%2F0X0000000beM%2Fa_la2G278sMR_jBfszmZLFWGgyrH1WdPpxdT.NMRzL8&asPdf=false

stm322xg_eval_i2c_ee_c.txt : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0qO&d=%2Fa%2F0X0000000beH%2FthU3281N2U5g5yr5W2CGPkR9009h3OLzf_Nd_7sLLn0&asPdf=false

stm322xg_eval_i2c_ee_h.txt : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0qJ&d=%2Fa%2F0X0000000beI%2Fsoc3bkUh28hF8VnT3.2zFEnWr76dnhlZGz1Lr4dY_Dg&asPdf=false

lcyc51 · ‎2011-12-11

Posted on December 12, 2011 at 08:39

I dare not use hardware I2C on STM32 MCUs and offer fell accross the problem as you said. Now I have seen the reply Linda suggested. I tested using DMA to transfer I2C data and it is really valid. After one hour aging test, the function is no problem. Thank you, Linda.

simonlee0311 · ‎2012-03-13

Posted on March 14, 2012 at 03:49

Dear DonTse Tse

Good day. I also have same problem with you.

I have checked my setting, and it is same as yours.

I modify the code form DCMI example which is in STM32F2xx_StdPeriph_Lib_V1.0.0.

Do you found the problem of this issue? If you have, would please provide me some suggestions to fix it?

Thanks and best regards,

emalund · ‎2012-03-14

Posted on March 14, 2012 at 14:04

I have not even seen a STM32F2xx but have to ask:

is the horrible, awful, terrible, shitty, crappy I²C interface from the f1's also in the f2's?

Erik

simonlee0311 · ‎2012-03-15

Posted on March 15, 2012 at 08:48

Dear All

I have finished this problem, and it works very well. God!!! It wasted so much time.

The below is my setting code, just for you guys reference.

PB8 -> SCL(with pull-high resistor 10Kohm), PB9 -> SDA(with pull-high resistor 10Kohm)

void I2C1_Config(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

I2C_InitTypeDef I2C_InitStruct;

/* I2C1 clock enable */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);

/* GPIOB clock enable */

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

/* Connect I2C1 pins to AF4 ************************************************/

GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_I2C1); //PB8 -> I2C1_SCL

GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1); //PB9 -> I2C1_SDA

/* Configure I2C1 GPIOs (Change PB8 and PB9 to AF mode**********************/

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz; //

GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOB, &GPIO_InitStructure);

/* Configure I2C1 ***********************************************************/

I2C_DeInit(I2C1); /* I2C DeInit */

/* Enable the I2C peripheral */

I2C_Cmd(I2C1, ENABLE);

/* Set the I2C structure parameters */

I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;

I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;

I2C_InitStruct.I2C_OwnAddress1 = 0xFE; //Master address

I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;

I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; //7 bit address mode

I2C_InitStruct.I2C_ClockSpeed = 30000; // speed = 300K

/* Initialize the I2C peripheral w/ selected parameters */

I2C_Init(I2C1, &I2C_InitStruct);

}

przemoga · ‎2012-04-03

Posted on April 03, 2012 at 19:05

Hi ! I read your post about problem with I2C and I think I have the same. After sending adress by I2C, the ADDR flag in SR1 register is not set but at the same time AF Flag is setting up. I do not use std peripherial libs and program on stm32f407 chip. Could you please send me your code or state of your registers taken from debugger ? I would be very grateful.