I2C implementation for STM32

[mabl]

I'll enhance the resolution of the scope and get back to you

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[matis]

Fixed it

I misinterpeted the documentation of the MAX7311.

Code: Select all

void init_max7311(void)
{
#define RXBYTES 0
#define TXBYTES 3
   max7311_tx_data[0] = 0x06; /* Port 1 configuration */
   max7311_tx_data[1] = 0xFF; /* Set IO00-IO07 as input */
   max7311_tx_data[2] = 0x00; /* Set IO08-IO15 as output */
   /* transmit out 3 bytes */
   i2cAcquireBus(&I2CD1);
   i2cMasterTransmit(&I2CD1, &max7311, max7311_addr, max7311_tx_data, TXBYTES, max7311_rx_data, RXBYTES);
   while (I2CD1.id_state != I2C_READY)
   {
      chThdSleepMilliseconds(1);
   }
   i2cReleaseBus(&I2CD1);
   max7311_tx_data[0] = 0x02; /* Output port 1  */
   max7311_tx_data[1] = 0x00; /* Set IO00-IO07 low / dont care */
   max7311_tx_data[2] = 0x00; /* Set IO08-IO15 high */
   /* transmit out 3 bytes */
   i2cAcquireBus(&I2CD1);
   i2cMasterTransmit(&I2CD1, &max7311, max7311_addr, max7311_tx_data, TXBYTES, max7311_rx_data, RXBYTES);
   while (I2CD1.id_state != I2C_READY)
   {
      chThdSleepMilliseconds(1);
   }
   i2cReleaseBus(&I2CD1);
#undef RXBYTES
#undef TXBYTES
}

Did the trick. The registers needed to be written one by one, each with the address header byte. The status outputs are also inverted, therefore a 0x00 is needed on the IO08-IO15 to turn them high.

[Badger]

I've been using the i2c drivers in a c++ application and I have a request: can we either have a void pointer in I2CSlaveConfig to use as a generic param passing pointer or a hook to allow adding other values into the struct?

[barthess]

Hi, Badger.
Technically, adding a void pointer in struct is not a problem. Question to Giovanni, whether it correspond the ideology of the OS? Or may be OS has other mechanism for this purpose?

[Giovanni]

Hi,

Some driver already have hook macros to extend structures so that would not be a problem from my point of view.

Giovanni

[barthess]

What driver(s) looking for examples?

[Giovanni]

For example in the STM32 GPT driver you can see:

Code: Select all

#if defined(GPT_DRIVER_EXT_FIELDS)
  GPT_DRIVER_EXT_FIELDS
#endif

inside the GPTDriver structure, the same approach could be used for configuration structures, something like GPT_CONFIG_EXT_FIELDS.

Giovanni

[barthess]

Hook added at revision 3189.

[barthess]

Hi all.
I have try to realize synchronous driver. It turned out not to much simpler or smaller. Also I have not oscilloscope nor logical analyzer to perform comprehensive tests.

I think that the current callback based driver is stable enough to merge to trunk. Is there any suggestions and comments?

Where to move from os\hal\dox\i2c.dox STM32 specific documentation?

[Giovanni]

I am still evaluating the synchronous option but in the meanwhile lets merge this one.

Any feedback on the current implementation before merging?

Giovanni