i have 3 analog pins from a pcb board of 10+ pressure sensors on each board. its connected to the A8,A10 and A11 of the arduino mega 2560. while taking the readings without xbee shield with cable, give data more closer to the correct data. At the same condition with xbee shield without cable (wireless) shows data higher than the correct data. Again i connected the cable keeping the xbee shield and get the data through the cable shows the data higher than correct data. please suggest a solution for this...urgent,,
Which analog reference mode are you using. If the default reference, it will vary with the load on Vcc. The xbee may be affecting Vcc and in turn the ADC measurements. Measure Vcc under all conditions.