ESP8266 Community Forum

- Wed Oct 02, 2019 8:19 pm #84011 Hi, I'm Using a ESP 12-e module in arduino IDE. I want to generate a clock and a data on my pins to communicate with a custom device. Something like this:

This is my related piece of code:

Code: Select allpinMode(CLK , OUTPUT);
  pinMode(DOUT , OUTPUT);
//
void Write_Bit_0(void){
    digitalWrite( DOUT , LOW );
    digitalWrite( CLK , HIGH );
    digitalWrite( CLK , LOW );
  }
void Write_Bit_1(void){
    digitalWrite( DOUT , HIGH);
    digitalWrite( CLK , HIGH );
    digitalWrite( CLK , LOW );
  }
//
....

My problem is to increase CLK frequency. it seems that digitalWrite command take about 800 ESP clock to run!(I measured it with ESP.getCycleCount()).
Can anyone suggest a solution to increase CLK frequency up to 8 Mhz?
Thanks

- Thu Oct 03, 2019 11:42 pm #84027 You probably don't get 8MHz, but you have to direct access GPIO registers - for example see this https://forum.arduino.cc/index.php?topic=423340.0

- Fri Oct 04, 2019 2:39 am #84028 That looks like SPI with the right clock phase and polarity set up and data length set to 8.

By using the hardware SPI you can get very high clock frequencies; 8MHz no problem. Plus much lower software overhead as you are writing bytes rather than bit banging.

- Sun Oct 13, 2019 3:08 am #84143 Also if your timing such tight, it may not be possible to use arduino.

I suggest you move your question to the arduino section. This has nothing to do with hardware.