bmi160

[espruino-discuss]

Posted at 2020-01-25 by QueensCrown

Hi, I bought bosh bmi160 Gyro & accelerometer but I couldnt find any module in espruino module page. I did some research found docs for sensor. I tried i2c connection I am able to write data and see data changing with different commands given in docs. The problem is when I read console by interval function I get uint8Array I dont know what to do with it I tried to convert to hex I got different data with different commands. According to Bosh Docs (I put link to bottom) if I send 0x00 I will read chipId I sended code with following code

I2C1.setup({ scl : NodeMCU.D6, sda: NodeMCU.D5});

function toHexString (byteArray) {
  const chars = new Uint8Array(byteArray.length * 2);
  const alpha = 'a'.charCodeAt(0) - 10;
  const digit = '0'.charCodeAt(0);

  let p = 0;
  for (let i = 0; i < byteArray.length; i++) {
      let nibble = byteArray[i] >>> 4;
      chars[p++] = nibble > 9 ? nibble + alpha : nibble + digit;
      nibble = byteArray[i] & 0xF;
      chars[p++] = nibble > 9 ? nibble + alpha : nibble + digit;    
  }
  return String.fromCharCode.apply(null, chars);
}

setInterval(function() {
    var uint = I2C1.readFrom(0x69,16);
    var hex = toHexString(uint);
    console.log(uint);
    console.log(hex);
})

Result:

d1210000000000000000000000000000

new Uint8Array([209, 33, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
...

https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmi160-ds000.pdf#page=19

Sorry about my english I tried my best

[espruino-discuss]

Posted at 2020-01-25 by @MaBecker

Hi,

check the BoschSenortec github account, there is a completely [BMI160 driver]
(https://github.com/BoschSensortec/BMI160_driver) written in c (rewriting c code to javascript is not that hard).

Hint: Start with Init the sensor and then try to Read some values.

---

Posted at 2020-01-25 by AkosLukacs

You are on the right way, the 209 decimal in the response is 0b11010001 as shown on the datasheet screenshot!

---

Posted at 2020-01-25 by QueensCrown

Thank you for all responses,

They read the sensor ready data like this

        rslt = bme280_set_regs(&reg_addr, &soft_rst_cmd, 1, dev);

       (rslt == BME280_OK)
       //BME280_OK = INT8_C(0)

I did:

var ERR_REG = 0x02;//According to docs at page 49
 var adr = 0x69;
 var len = 5;// 
I2C1.writeTo(adr,ERR_REG);
  var response = toHexString(I2C1.readFrom(adr,16)).slice(0,len);
   //Response = 00000

If the data is correct 5 zero bit is tells sensor is working correct

But when I tried to get chip id with same code with len = 7 I get 1414240 (Without converting to hex [ 20, 20, 36, 4, 10, 24, 72 ]). In the driver I must get UINT8_C(0x60) or 0x60 the thing is is 0x60 equal to 1414240 ? or am I converting wrong?