Converting unsigned 16-bit sample codes to volts Sample Clauses

Converting unsigned 16-bit sample codes to volts. An unsigned code of 32768 (0x8000) represents ~0V input voltage, 65535 (0xFFFF) represents a positive full-scale input voltage, and 0 represents a negative full-scale input voltage. The following table illustrates how unsigned 16-bit sample codes map to values in volts according to the full-scale input range of an input channel. Sample code in decimal Sample code in hex Sample value as a percentage of full- scale input range Sample value in volts if full-scale input range is ±100 mV Sample value in volts if full- scale input range is ±1 V 0 0x0000 -100% -100 mV -1 V 16384 0x4000 -50% -50 mV -.5 V 32768 0x8000 0% 0 V 0V 49152 0xC000 +50% 50 mV +.5 V 65535 0xFFFF +100% +100 mV +1 V The following code fragment demonstrates how to convert a 2-byte sample value containing an unsigned 16-bit sample code to in volts. double SampleToVoltsU16(U16 sampleValue, double inputRange_volts) { // AlazarTech digitizers are calibrated as follows int bitsPerSample = 16; double codeZero = (1 << (bitsPerSample - 1)) - 0.5; double codeRange = (1 << (bitsPerSample - 1)) - 0.5; // Convert sample code to volts double sampleVolts = inputRange_volts * ((double) (sampleValue - codeZero) / codeRange); return sampleVolts; }