Problem with the I2C demo from the testhal directory

[pklink]

Hello Everybody,

I recently set up chibiOS on my STM32F4-Discovery and now tried some demos that came along with chibiOS v2.6.0RC1. After running the first demo, which is located in the "demos" directory, I tried to run the I2C demo from "testhal", since I'm going to need I2C on this board for an upcoming project. And so I loaded the project into workspace (I'm using chibiStudio) und flashed it to the STM32. As I opened a terminal in order to see the data coming from the accelerometer, I recognized that there was no output. After a short check I could exclude that the failure comes from the RS232, because of an initial text I sent and also I exchangend the board to ensure that the accelerometer is not broken. Finally I started debugging and found out, that this line of code causes the error:

status = i2cMasterTransmitTimeout(&I2CD2, mma8451_addr, txbuf, 2, rxbuf, 0, tmo);

The function terminates with a timeout flag, so that the next call to the I2C bus ends in a Kernel halt. I also set the timeout from 4 milliseconds to 100 milliseconds but had the same result.

Is there anyone, who has a running example for the I2C using the onboard accelerometer on a STM32F4-Discovery or has a clue how the problem can be solved?

Thank you in advance,
Pascal Klink

[Giovanni]

Hi,

The accelerometer on the F4-Discovery is connected through an SPI not an I2C. The correct demo you should use is ./demos/ARMCM4-STM32F407-DISCOVERY-MEMS.

Giovanni

[pklink]

Hi Giovanni,

thank you for the quick help. Now I know I don't have to be curious about this issue and can move on to connecting external devices to the I2C bus.

Pascal Klink

[Giovanni]

Hi,

I2C can be problematic on the STM32 up to the F4 because HW quircks (F0, F3 and following use a new peripheral).

We went into a lot of trouble in order to get a stable driver, please make sure to read the guide here: http://www.chibios.org/dokuwiki/doku.ph ... e_shooting

Giovanni

[barthess]

pklink,
That test was written for special board not Discovery. Because Discovery has no I2C peripherals.