t. Is 10-bit A/D conversion on a Velleman K8055 or K8055N experiment board truly achievable?

QUESTION:

I found that the K8055 and K8055N have so much noise on the supply rail, which is also used as ADC reference voltage, that 10 bits precision are not really achievable.

ANSWER:

You should check your PC's (or the workstation's that you use) power supply, or the USB cables that you use. I use quality USB 2.0 cables and a quality 650 W power supply in my PC and I have never experienced such problems. 10-bits A/D conversion is easily achievable, if you setup the microcontroller's ADC according to Microchip's specifications. It is important to know that all sound cards and inbuilt sound chips on PC’s motherboards work from 16-bits up to 32-bits precision and they also do not experience such problems.