ESP12-E with ADXL345 I2C: Incorrect Axis Values on Lolin NodeMCU V3

Welcome,

Maybe you can find some spuds .

The following program uploaded to anything with an ATMEL works fine and shows correct +/-2 measurements from the accelerometer. When I upload the same to the Lolin wifi esp8266 nodemcu v3 (ESP12-E) the result is completely different. There are no negative values and some axes jump up to a value of 255. where is the difference?

#include <Wire.h> // Wire library - used for I2C communication
int ADXL345 = 0x53; // The ADXL345 sensor I2C address
float X_out, Y_out, Z_out; // Outputs
void setup() {
Serial.begin(115200); // Initiate serial communication for printing the results on the Serial monitor
Wire.begin(); // Initiate the Wire library
// Set ADXL345 in measuring mode
Wire.beginTransmission(ADXL345); // Start communicating with the device
Wire.write(0x2D); // Access/ talk to POWER_CTL Register - 0x2D
// Enable measurement
Wire.write(8); // (8dec -> 0000 1000 binary) Bit D3 High for measuring enable
Wire.endTransmission();
delay(10);
}
void loop() {
// === Read acceleromter data === //.
Wire.beginTransmission(ADXL345);
Wire.write(0x32); // Start with register 0x32 (ACCEL_XOUT_H)
Wire.endTransmission(false);
Wire.requestFrom(ADXL345, 6, true); // Read 6 registers total, each axis value is stored in 2 registers
X_out = ( Wire.read()| Wire.read() << 8); // X-axis value
X_out = X_out/256; //For a range of +-2g, we need to divide the raw values by 256, according to the datasheet
Y_out = ( Wire.read()| Wire.read() << 8); // Y-axis value
Y_out = Y_out/256;
Z_out = ( Wire.read()| Wire.read() << 8); // Z-axis value
Z_out = Z_out/256;
Serial.print("Xa= ");
Serial.print(X_out);
Serial.print(" Ya= ");
Serial.print(Y_out);
Serial.print(" Za= ");
Serial.println(Z_out);
delay(10);
}

What voltage do you supply to the ADXL345 module when you connect it to the NodeMCU?

3V but 5V can also be supplied to this circuit.
Problem solved, had to convert 8bit data to 16to using the following.
X_out = (int16_t( Wire.read() | Wire.read() << 8)) / 256.0;