lpcware

ADC output

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
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? 

Attachments

Outcomes