Question

The following code has been given to you in Ex² and Ex³ when you read the ADS1015 data and convert that to a measured voltage. Explain the function of this code.

a. LOW = (data 0xFF00) >> 8;
b. high = (data 0x00FF) << 8;
c. Value = (High | low)>>4;
d. if (value > 0x07FF)
e.
f. value

Answer 1

The provided code handles data from an ADS1015 ADC, converting raw binary data to a measured voltage by separating high and low bytes, recombining them to form the correct value, and performing sign extension if the value is negative.

Step-by-step explanation:

The code provided is used for reading data from an ADS1015 analog-to-digital converter (ADC) and converting that data to a measured voltage. The ADS1015 is a precision ADC that uses I2C to communicate with microcontrollers like Arduino or Raspberry Pi. Each line of the code has a specific function:

• LOW = (data & 0xFF00) >> 8; isolates the high byte of the ADC data and then shifts it right by 8 bits to form the lower part of the 12-bit ADC value.
• high = (data & 0x00FF) << 8; isolates the low byte and shifts it left by 8 bits to make it the higher part of the 12-bit value.
• Value = (High | low) >> 4; combines the high and low parts using the bitwise OR operation to form a 16-bit number, then shifts it right by 4 bits to adjust for the 12-bit resolution of the ADS1015.
• If (value > 0x07FF) checks whether the value is negative in a 2's complement representation. The 0x07FF is the largest positive value for a signed 12-bit number.
• value |= 0xF000; is used to perform a sign extension. If the value is determined to be negative, the statement sets the upper four bits to 1's to maintain the correct negative value in 16-bits.

This process is essential for accurately interpreting the voltage readings from the sensor.