Help: Analog Read 1023 for 3.56 Volt

Hi

I need help. (Rookie turning Pro ..... :))

I am busy building a project where I use the Analog Pin (Mega2560) to read a voltage from a sort like voltage divider to use as information to convert it to a weight (strain gauges).

The datasheets show 1023 represent 5 Volt. If I use the Mega on my computer this is true. However when I connect my Mega to my project, 1023 represent 3.56 Volt.

How can I solve this?

I have tried: 1. Stabilizing my power sources with caps, this did not help. I am using a standard Arduino 5v Power supply that provide 5,3 Volt. 2. Measuring total current delivered, but it is still below the limits.

Any advice?

Thank you

It looks like your not getting 5V to power your Mega. By default the analogue inputs use the chips power supply as the analogue reference so if it's really 5v then that would equal 1023. As your getting 1023 at 3.5V your probably powering the chip at this voltage. Where is this 5,3 (should this be 5.3) supply connected on the arduino?