STM32f4x9i EVAL ( 429 /439 ) board camera module problem

[Mariano Abad]

Posted on June 07, 2014 at 00:58

Hi guys , I'm facing some problem(s) while trying to get some video from the camera module included with both 4x9 EVAL boards. The demo program  shows ''Error while Initializing Camera Interface''

While debugging the camera initialization ,ov2640_ReadID() returns 0x00.I've attached a logic analizer to the scl/sda pins on the module and I can clearly see the camera is not responding to anything , I've double checked the camera module address in the code and in the datasheet and they match.  I've tested this behavior on two different evaluation boards so i'm not sure if it's hardware related or not.Hope someone  shed some lights on this problem. #stm32f4 #eval-board

[Tesla DeLorean]

Posted on June 07, 2014 at 01:31

I don't have a camera on mine, but I think you'd have to pay specific attention to jumper, solder bridge, and component modifications/settings required.

[Mariano Abad]

Posted on June 07, 2014 at 02:38Thanks clive for the quick response.Just checked the schematics of the boards and didn't see anything relevant to be modified. Sneaked the ov2640 datasheet and found the i2c lines are rated max 2.3v ( 1.8v) , however I'm measuring 2.8x volts at both ends of R3 and R4 (sda/scl) on the MB1066 ( the camera module ) . Could this problem be related to a bad design on these boards? 

[Mariano Abad]

Posted on June 07, 2014 at 03:27Alrighty , finally found the problem. PWDWN / STDBY / whatever they decided to name it was tied UP everytime , It will take me a little while to figure out wetehr it can be fixed on the software or if it will need a new resistor to be added on the board

[stm322399]

Posted on June 07, 2014 at 08:49

The eval board has a GPIOexpander that controls two signals of the camera module: Reset and powerdown.

I can make it work the following way: * reset=0, pwrdn=1 * perform ov2640 init * reset=0, pwrdn=0 * DCMI init etc ...

[Mariano Abad]

Posted on June 07, 2014 at 20:14

Thanks guys , it did the trick.

STM32Cube_FW_F4_V1.1.0\Drivers\BSP\STM324x9I_EVAL\stm324x9i_eval_io.c

uint8_t BSP_IO_Init(
void
)
{
uint8_t ret = IO_ERROR;
/* Read ID and verify the IO expander is ready */
if
(stmpe1600_io_drv.ReadID(IO_I2C_ADDRESS) == STMPE1600_ID)
{
/* Initialize the IO driver structure */
io_driver = &stmpe1600_io_drv;
ret = IO_OK;
}
if
(ret == IO_OK)
{
io_driver->Init(IO_I2C_ADDRESS);
io_driver->Start(IO_I2C_ADDRESS, IO_PIN_ALL);
io_driver->Config(IO_I2C_ADDRESS,IO_PIN_0,IO_MODE_OUTPUT);
io_driver->Config(IO_I2C_ADDRESS,IO_PIN_2,IO_MODE_OUTPUT);
io_driver->WritePin(IO_I2C_ADDRESS,IO_PIN_0,1);
io_driver->WritePin(IO_I2C_ADDRESS,IO_PIN_2,0);
}
return
ret;
}