Content originally posted in LPCWare by Shoaib on Sun Sep 14 15:10:46 MST 2014
Hi everyone,
I am using LPC1769 to measure current in a DC motor circuit and had some queries regarding the ADC of the microcontroller. I am using LTSR 15-np as the current sensor in +/- 5A range.
The sensor gives an output of 2.5V for 0 A current and increases upto 4.5V for 5A current.
When the motor circuit is disconnected (ie no current in the circuit)the adc is a giving a value of 3298/3299. I was expecting a value close to 2048.
I did not change the reference voltage given to the VREFP pin. Do I need to give 5V reference for this range?