Improve framerate by changing image data transmission

[supercrab]

I know this branch is maintenance mode but I've discovered something interesting.

I've found during some tests of my cheapo I2C OLED that you can send it all the image data in one go! Am pretty sure most screens support this to make updates faster by reducing the amount of data transferred.

In ArduiPi_OLED.cpp:914 a buffer array is created with 17 elements char buff[17] and the image data is sent in 16 data bytes. I reckon sending the whole array in one go will improve frame rate.

ArduiPi_OLED.cpp line 914 - 943

    char buff[1025];

    // Setup D/C to switch to data mode
    buff[0] = SSD_Data_Mode;

    if (oled_type == OLED_SH1106_I2C_128x64) {
      for (uint8_t k = 0; k < 8; k++) {
        sendCommand(0xB0 + k); // set page addressSSD_Data_Mode;
        sendCommand(0x02);     // set lower column address
        sendCommand(0x10);     // set higher column address
      }
    }

    // loop trough all OLED buffer
    for (i = 0; i < oled_buff_size; i++) {
      buff[i + 1] = buff[i];
    }

    fastI2Cwrite(buff, 1025);

I will report back when I test this on a pi and see how much of a difference it makes.

Cheers
Mase

[antiprism]

Hi Mase

I don't know how efficient the code is, as it is Arduino code that was converted to work on the Raspberry Pi. It will be interesting to see what results you get.

Adrian.

[supercrab]

The code looks fine, it's just this particular part doesn't seem to be that efficient for some reason.
There are 124*64 = 8192 pixels to send, which is 1024 bytes.
The current code would send 16 data bytes + 1 control byte 64 times by calling fastI2Cwrite().
The new code would send 1 control byte + 1024 data bytes with a single call to fastI2Cwrite().
Will let ya know!