Touch GFX and I2C sensors on the same bus

[LKade.1]

Hi All ,

I am doing a projet using STM32f469I disco board with Touch GFX i able to run the Touch GFX GUI properly but when i try to conncet the I2C sensors to the same bus the I2C is always busy with the Touch GFX. hence i am not able to initialize the I2C sensors. Could anyone provide something to wok with it Such that the Touch GFX and other I2c sensors are on the same Bus and works efficentlz.

With Regards

Lakshminarayana KS

[mƎALLEm]

Hello,

Be careful, if you are using I2C1 (PB8/PB9) for your sensors, LCD touch panel is using the same bus.. Refer to the schematics from this link.

So you need to manage I2C bus addresses .. LCD touch panel I2C address is 0x54 and pull-up resistors are already available on the board.

Arduino connector:

LCD touch panel:

MCU:

 SofLit

[LKade.1]

Hi SofLit,

Thanks i am Aware that I2C1 is located on the PB8 and PB9 but my problem is when Touch GFX hold the line busy always without allowing the bus for other sensors hence not able to initialize the sensors or able to work with it.( i.e My STM32f469I discovery has only one I2C bus avaiable for both touch and other sensors)

Hope you understand what i mean.

Thanks in adavance

[austinproto]

Did you figure this out?  I am trying to read an LM92 I2C temp sensor and all I see is the LCD touch traffic (address 0x70).

I am not sure why ST32F469 bring out only one I2C and it is the one used by the LCD :(

I am using the HAL_I2C_Mem_Read command and I have extern I2C_HandleTypeDef hi2c1 in Model.cpp.

 

[austinproto]

I got the I2C1 to work reading the sensor.  The answer is that it has to be initialized even though the LCD touch is already using it!  I added HAL_I2C_Init(&hi2c1) .  I then use HAL_I2C_Master_Receive to read the data inside Model.cpp.

I added it to the main.c file:

 /* Initialize all configured peripherals */
 MX_GPIO_Init();
 MX_CRC_Init();
 MX_DMA2D_Init();
 MX_DSIHOST_DSI_Init();
 MX_FMC_Init();
 MX_LTDC_Init();
 MX_QUADSPI_Init();
 MX_I2C1_Init();
 MX_TouchGFX_Init();
 /* Call PreOsInit function */
 MX_TouchGFX_PreOSInit();
 /* USER CODE BEGIN 2 */
 HAL_I2C_Init(&hi2c1);
 /* USER CODE END 2 */

 /* Init scheduler */
 osKernelInitialize();

If anyone knows if this is the best place to do the init, please let me know.  Thanks!