DCMI and SDIO problem

zeros_and_ones1991 · ‎2014-10-24

Posted on October 25, 2014 at 00:16

Hullo guys , I 'm working with STM32F429I (on Open board from wave share) , and I m interfacing the OV2640 Camera , at the same time I have SD card attached , now the problem is that i can receive frames properly from the cam , but I can not seem to even initialize the card while using the cam , the DCMI and SDIO have shared pins , i disable the IOs from the DCMI after i get the frame , then i enable them for the SDIO .

When ever i remove the Camera , the card works perfectly . The clock supply to the DCMI is stopped after i receive the frame (so that it wont disturb the IOs of the SD)

but still , i can not seem to make them work on the same hardware Pins .

Any solutions ??????

Tesla DeLorean · ‎2014-10-24

Posted on October 25, 2014 at 01:11

Which pin(s) conflict? It is possible that the camera could continue to drive a pin high/low even if it's clock is stopped/disabled. Consider using a buffer chip so you can tri-state the pin(s)

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Montassar BEN ROMDHANE_O · ‎2014-10-28

Posted on October 28, 2014 at 14:42

Hi Muhammad,

We've already faced this limitation of shared pins between the SDCard and the Camera module, when using the STM324x9I_EVAL board.

When the camera module is plugged the SDCard is niether detected nor intiliazed otherwise it is detected and intiliazed.

To resolve this issue, you have just to set the camera STANDBY pin (IO_PIN_0) within the Camera init function, and reset this STANDBY pin within the Camera stop function.

Are you using an STM32Cube_FW_F4 package ?

Let me know if this helps or if you have further questions.

Regards,

Heisenberg.