I2c frequency

[fary99]

Board

esp32

Device Description

esp32

Hardware Configuration

not have

Version

v2.0.1

IDE Name

Arduino IDE

Operating System

windows10

Flash frequency

80

PSRAM enabled

no

Upload speed

921600

Description

I want to change the I2C clock, but I find that if the frequency exceeds 100K, the IIC frequency will not change to the size I set. For example, if I set 400K, it can only reach about 350K. Is there any way to optimize it?

Sketch

#include "Wire.h"

void setup() {
  Serial.begin(115200);
  Wire.begin(SDA,SCL,(uint32_t)409600);
}

void loop() {
  byte error, address;
  int nDevices = 0;

  Serial.println("Scanning for I2C devices ...");
  for(address = 0x01; address < 0x7f; address++){
    Wire.beginTransmission(address);
    error = Wire.endTransmission();
  }
}

Debug Message

not have

Other Steps to Reproduce

not have

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[Jason2866]

Please try latest Arduino git version. Many changes since version 2.0.1
No support anymore for v2.0.1. Release of new version 2.0.3 will be in a few days

[VojtechBartoska]

Hi @fary99, did you try it with v2.0.2?

[fary99]

Tried it. Same thing

[VojtechBartoska]

Hello @fary99, thanks for your test.

@PilnyTomas Can you please test this issue on the latest master? In the meantime.

[PilnyTomas]

Hi, what exactly does it means that the frequency does not change - are you checking it on an oscilloscope, or how?
Right now I can check it only via software and it seems ok. The maximum frequency is 1 million - anything above that will set that 1 million.
Please try to call Wire.getClock() to see what the software has to say about the requested clock frequency.
It is also good practice to check the result of functions. Wire.begin returns true if started successfully.