schm1tz1 / arduino-ms5xxx Goto Github PK

In the file "shab/flight_software/MS5xxx.cpp", the Wire.requestFrom() is followed by some Wire.read() and then a Wire.endTransmission(). That Wire.endTransmission() may be removed.

Explanation: Common-mistakes#2

When testing the MS5607 with the MS5xxx library it compiles fine with an Arduino uno but when I compile it with a Seeduino Zero I
get errors:

error: expected primary-expression before 'unsigned' unsigned long D1=0;
error: expected primary-expression before 'unsigned' unsigned long D2=0;

error: lvalue required as left operand of assignment D2=read_adc(MS5xxx_CMD_ADC_D2+MS5xxx_CMD_ADC_4096);
error: lvalue required as left operand of assignment D1=read_adc(MS5xxx_CMD_ADC_D1+MS5xxx_CMD_ADC_4096);

I have newly installed Arduino IDE v1.8.13 and downloaded the MS5xxx lib, as I remember from arduinolibraries.info but the example program Simple Server does not run.
I always get "Error connecting..." means can not connect to the sensor.
Because I am not a specialist with this breakout board and not that code master, could you help me what I could do ?
Regards Gerald

Hello Roman,
I have a problem with Arduino-MS5xxx library (Using MS5607 Parallax) with Arduino 101, Arduino IDE 1.6.13 and 1.8.1.
I tested with Arduino 2009, Mega and Mega R3 and everything works very well.
I am a beginner and I can not find a solution.

I tried the example "29124-Altimeter-Module-KickStart" on https://www.parallax.com/product/29124 and it works but I need the very low pressure and temperature for a weather balloon.

I apologize for my English, and for how to report a problem that maybe is not the correct way.

Best regards

Flavio

I used a program based off the example sketch to print the calibration data and current temperature from my MS5607 barometer. On the nRF52832 Feather from Adafruit, it produces the following:

Starting on MS5xxx
C0: 20
C1: 4294967039
C2: 4294967039
C3: 4294967039
C4: 4294967039
C5: 4294967039
C6: 4294967039
C7: 4294967039
-11258997720986.12 deg c
-11258997720986.12 deg c
-11258997720986.12 deg c

However, if we upload it to an ESP32 Feather on the same board with the same hardware, we get the following:

Starting on MS5xxx
C0: 20
C1: 37555
C2: 34296
C3: 24510
C4: 23248
C5: 34466
C6: 28969
C7: 53513
11.23 deg c
11.25 deg c
11.25 deg c

I further verified that my sensor was working correctly by writing my own code to print out PROM values:

  Wire.beginTransmission(ADDRESS);
  Wire.write(0xA2);
  Wire.endTransmission();
  Wire.requestFrom(ADDRESS, 2);
  uint8_t higher_8 = Wire.read();
  uint8_t lower_8 = Wire.read();
  uint16_t value = (higher_8 << 8) | lower_8; // Read the first 8 bits; shift them left 8; OR with the next 8 bits
  Serial.print("Higher 8: "); Serial.print(higher_8, BIN); Serial.print("Lower 8: "); Serial.print(lower_8, BIN); Serial.print("Full: "); Serial.println(value, DEC); 

Which printed the correct value for A2

After digging into the library, I noticed calls to _Wire->endTransmission(true); after reading bytes from serial; removing these calls caused the calibration readings and read temperature to be equivalent to with the ESP32. Why is this function call present after reading bytes from i2c?

The setup: I'm working with an arduino pro mini(using the arduino bootloader) and a MS5607 barometer.

The Problem: ReadCalc was returning the wrong result (which I only knew because I fixed Calc_CRC4)
The Solution: replace "char c" with " unsigned int c"

The working code*:

void MS5xxx::ReadProm() {
send_cmd(MS5xxx_CMD_RESET);
delay(3);

for(uint8_t i=0;i<8;i++) 
{
    C[i]=0x0000;
    send_cmd(MS5xxx_CMD_PROM_RD+2*i);
    _Wire->requestFrom(i2caddr, 2);

    unsigned int c = _Wire->read();
    C[i] = (c << 8);
    c = _Wire->read();
    C[i] += c;
    _Wire->endTransmission(true);
}

}

The Second Problem: Calc_CRC4 was returning zero.
The Second Solution: I adapted the "crc4" function from document AN520 by measurement specialties

The working code*:

unsigned char MS5xxx::Calc_CRC4()
{
int cnt; // simple counter
unsigned int n_rem; // crc reminder
unsigned int crc_read; // original value of the crc
unsigned char n_bit;
n_rem = 0x00;
crc_read=C[7]; //save read CRC
C[7]=(0xFF00 & (C[7])); //CRC byte is replaced by 0
for (cnt = 0; cnt < 16; cnt++) // operation is performed on bytes
{// choose LSB or MSB
if (cnt%2==1) n_rem ^= (unsigned short) ((C[cnt>>1]) & 0x00FF);
else n_rem ^= (unsigned short) (C[cnt>>1]>>8);
for (n_bit = 8; n_bit > 0; n_bit--)
{
if (n_rem & (0x8000))
{
n_rem = (n_rem << 1) ^ 0x3000;
}
else
{
n_rem = (n_rem << 1);
}
}
}
n_rem= (0x000F & (n_rem >> 12)); // final 4-bit reminder is CRC code
C[7]=crc_read; // restore the crc_read to its original place
return (n_rem ^ 0x0);

}

To test the code, per AN520, I added this function*:

unsigned char MS5xxx::CRCcodeTest(){
unsigned int nprom[] = {0x3132,0x3334,0x3536,0x3738,0x3940,0x4142,0x4344,0x4500}; //expected output is 0xB
for(uint8_t i=0;i<8;i++)
{
C[i] = nprom[i];
}
unsigned char crc = Calc_CRC4(); //expected output is 0xB
ReadProm();
return crc;

}

*note: after substituting in these new functions you will need to update the header appropriatly