Simple test for beginner with ESP32 and si5351 (with a M5StackStickCplus)

[robouden]

Sorry to bother, but it seems you are one of the few that got the ESP32 and the si5351 working nicely.
After downloading and looking at your code, I was trying to find out how to simply the code for my M5StackStickCplus to work. But I could not figure that out.to get the I2C working on pin G26 (SCL) and pin G0(SDA).

Please advise me how to make a simple .ino file with the modified libraries you made (Ii2c.h and si5351.h)

Regards,
Rob Oudendijk

[paulh002]

Hello Rob,

This repository is a bit older and the solution I used was to implement my own simple I2C functions. If you create the SI5351 class you can specify the SCL and SDA pins. Si5351::Si5351(uint8_t i2c_addr, uint8_t i2c_sda, uint8_t i2c_scl). In the file IO.CPP you can see the definition for the ports.

-------------------------------------------------------
Si5351
--------------------------------------------------------/

#define I2C_SDA2 16
#define I2C_SCL2 17
#define SI5351_XTAL_FREQ1 SI5351_XTAL_FREQ //25 mhz
//#define SI5351_XTAL_FREQ1 32000000

#define CLK_BFO_RX SI5351_CLK2
#define CLK_VFO_RX SI5351_CLK2
#define CLK_BFO_TX SI5351_CLK0
#define CLK_VFO_TX SI5351_CLK0
#define CLK_NA SI5351_CLK1

Si5351 si5351;
Si5351 si5351_bfo(SI5351_BUS_BASE_ADDR, I2C_SDA2, I2C_SCL2);

In the meantime there is a fix for the SI5351 library (https://github.com/etherkit/Si5351Arduino) but the maintainer did not implement it.
You have to change the SI5351::si5351_read method

Change Wire.requestFrom(i2c_bus_addr, (uint8_t)1, (uint8_t)false);

to Wire.requestFrom(i2c_bus_addr, (uint8_t)1); //, (uint8_t)false);

Than you can use the original library

[robouden]

Whooo, thank you so much for the fast reply.
I will check tomorrow and report back to you.

Warm regards,
Rob Oudendijk

[robouden]

Paul,

Just before going to bed. Tried the modifications you mentioned.
Worked great!! Now very simple code.

/*

---

• Copyright (c) 2022 YR-Design
• Visit for more information:
• https://docs.m5stack.com/en/core/m5stickc_plus
• I2C modified code from https://github.com/paulh002/VFO-ESP32-Si5351
• Describe: Display and Si5351 setup test
• Date: 2022/12/20

---

*/
#include "M5StickCPlus.h"
#include "si5351.h"
#include <Wire.h>

Si5351 si5351;

void setup() {
bool i2c_found;
// Start serial and initialize the Si5351
Serial.begin(9600);
i2c_found = si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);

M5.begin();
// Lcd display
M5.Lcd.fillScreen(BLACK);
M5.Lcd.setCursor(10, 10);
M5.Lcd.setTextColor(WHITE);
M5.Lcd.setTextSize(2);
M5.Lcd.setRotation(3);
delay(500);

//Check I2C
if(!i2c_found)
{
M5.Lcd.setTextColor(RED);
M5.Lcd.println("Error on I2C bus!");
}
else {
M5.Lcd.println("si5351 on I2C bus!");
}

delay(1000);
// text print
M5.Lcd.fillScreen(BLACK);
M5.Lcd.setCursor(10, 10);
M5.Lcd.setTextColor(WHITE);
M5.Lcd.setTextSize(2);
M5.Lcd.setRotation(3);
M5.Lcd.println("Si5351 test");
M5.Lcd.println();

// Set CLK0 to output 27.12 MHz
si5351.set_freq(2712000000ULL, SI5351_CLK0);
M5.Lcd.println(" CLK0 =27.12MHz");

}

void loop() {

}

[robouden]

Output from si5351 with new code at 27.12MHz

[paulh002]

Great that it works!

[robouden]

And here the M5StickCPlus and the Si5351.