Problems with i2c in esp8266 (MPU9250 [GY-91])

[espruino-discuss]

Posted at 2022-01-18 by user136941

Hello,

I'm trying to read a gyroscope (GY-91), that have an MPU-9250 inside with an BMP-280. I'm using this library But I have some problems.

When I'm run the code throw the next error:

Uncaught InternalError: I2CWrite: No ACK 0

I'm trying with a LCD i2c, in case that if is the module that is wrong, but got the same error. Also, doesn't work with D pins (D0, D1, D2...) only with numbers

//This doesn't work
I2C1.setup({ scl: D4, sda: D5 });
//This works
I2C1.setup({ scl: 2, sda: 14 });

After change the numbers the LCD works, but the MPU still don't.

Edit: A full log of the error:

Init MPU...
Uncaught InternalError: I2CWrite: No ACK 0
 at line 1 col 15
a.writeTo(12,c);return a.readFrom(12,d)
              ^
in function "rmag" called from line 1 col 49
...ew Uint8Array(this.rmag(3,7))).buffer),b=49120/32760;return{...
                              ^
in function "readMag" called from line 1 col 63
...eadGyro(),mag:this.readMag(),new:this.dataReady()}
                              ^
in function "read" called from line 3 col 23
      data = mpu.read();
                      ^
in function called from system
Uncaught Error: Unhandled promise rejection: InternalError: I2CWrite: No ACK 0

[espruino-discuss]

Posted at 2022-01-20 by @MaBecker

Please check the nodemcu class to get the correct pin names.

http://www.espruino.com/Reference#t_NodeMCU

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Posted at 2022-01-20 by @MaBecker

Check the wires and check the id of the i2c device.

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Posted at 2022-01-20 by user136941

Espruino have some function for scan all i2c devices connected?

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Posted at 2022-01-20 by @MaBecker

Try this one

http://forum.espruino.com/conversations/278556/#12663043

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Posted at 2022-01-21 by user136941

I tested it, detects two devices in 0x68 (that is MPU) and 0x76 (Is the BMP).

Here a full log of the error:

Init MPU...
Uncaught InternalError: I2CWrite: No ACK 0
 at line 1 col 15
a.writeTo(12,c);return a.readFrom(12,d)
              ^
in function "rmag" called from line 1 col 49
...ew Uint8Array(this.rmag(3,7))).buffer),b=49120/32760;return{...
                              ^
in function "readMag" called from line 1 col 63
...eadGyro(),mag:this.readMag(),new:this.dataReady()}
                              ^
in function "read" called from line 3 col 23
      data = mpu.read();
                      ^
in function called from system
Uncaught Error: Unhandled promise rejection: InternalError: I2CWrite: No ACK 0

---

Posted at 2022-01-21 by @MaBecker

Check the module and try some simple calls.

---

Posted at 2022-01-21 by user136941

I'm trying to call WHO_AM_I, don't know if this is the correct way to read data, but this is how it works the module, the example in page doesn't explain well, I mean, how to read 8 bits from device 0x68 to the address 0x75 :

I2C1.setup( {scl: NodeMCU.D4, sda: NodeMCU.D5} );

I2C1.writeTo(0x68,0x75);
var data = I2C1.readFrom(0x75,8);
console.log(data);

But still got the same error:

Uncaught InternalError: I2CRead: No ACK 0
 at line 5 col 33
  var data = I2C1.readFrom(0x3B,8);
                                ^
in function called from system