Posted on April 02, 2018 at 19:34Solved!
Seems like the code generated by CubeMX needs an interrupt when DMA is in the middle, then I needed to tell to CubeMX to generate the code for that interrupt and wait until the data transmission is completed, the relevant part of the code seems like this:
This is part of the file u8x8_cad.c:
static void u8x8_i2c_data_transfer(uint8_t arg_int, void *arg_ptr)
{
uint8_t buffer[arg_int];
uint8_t *ptr = arg_ptr;
buffer[0] = 0x40;
datatransmitted = 0;
for (int i = 1; i <= arg_int; i++) buffer[i] = *(ptr++);
// HAL_I2C_Master_Transmit(&hi2c1, 0x78, (uint8_t *)buffer, arg_int, HAL_MAX_DELAY);
HAL_I2C_Master_Transmit_DMA(&hi2c1, 0x78, buffer, arg_int +1);
while (!datatransmitted);
}
uint8_t u8x8_cad_ssd13xx_i2c(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
{
switch(msg)
{
case U8X8_MSG_CAD_SEND_CMD:
case U8X8_MSG_CAD_SEND_ARG:
; // esto es una declaracion vacia, para que el compilador permita la declaracion de la variable despues
uint8_t buffer[2];
buffer[0] = 0x00;
buffer[1] = arg_int;
datatransmitted = 0;
// HAL_I2C_Master_Transmit(&hi2c1, 0x78, (uint8_t*) buffer, 2, HAL_MAX_DELAY);
HAL_I2C_Master_Transmit_DMA(&hi2c1, 0x78, buffer , 2);
while (!datatransmitted);
break;
case U8X8_MSG_CAD_SEND_DATA:
u8x8_i2c_data_transfer(arg_int, arg_ptr);
break;
default:
return 0;
}
return 1;
}
datatransmitted is _Bool declared in main.c, then when the transmission is successful datatransmitted is set:
void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *hi2c)
{
datatransmitted = 1;
}
maybe is more 'elegant' (or maybe is even better) if I can check for the ACK of the I2C transmission... but this way it works!
