Powering the Arduino and other devices

Using Arduino Motors, Mechanics, Power and CNC
1

Hello,

I am currently working with an Arduino and to keep it simple I am controlling a servo motor with a sensor as my analogRead to keep an object at a fixed distance. I want to keep it half the total distance so I've been comparing the analogRead to the integer 512. This all works when I have separate power sources however if I use the same source for everything (Arduino, sensor, H-bridge, Motor) the analogRead is always off by about 100 bits or 1 mm. I've connected the sensors ground to the arduino and tried to make all the grounds common in the circuit. I've connected a power generator to the Arduino's Vin and realized that as soon as I change the Voltage going in (sweeping it from 5.5 to 8V) the arduino reads the analog value differently and the motor starts moving. I found the optimal voltage from the power generator to be 6.07V. This does not make any sense, I thought the Arduino can accept a range of Voltage supplies. I think it could be broken. Ive done a power analysis and there is sufficient current for the whole circuit. Any help would be greatly appreciated.

Thanks,

Nick

2

The voltage on Vin should be at least 7V to allow the onboard regulator to work correctly.

Please provide details of the components (servo/motor, H-bridge etc) and a schematic showing how everything is connected or powered. A servo does not need an H-bridge so it's not clear what you are really using.

And please post your code.

Steve