Problem reading analogue inputs on K8055 board

Kits PC Related Projects
1

Hi,

I’m using the demo software (and something I’ve programmed on which the code syntax is fine) and I’m having real, real trouble reading from the analogue inputs. Digital inputs are fine. Digital outputs are fine. I haven’t tested analogue outputs.

I get a varying reading on the analogue inputs when I change the values of ATT1 and ATT2, but whatever voltage (between 0 and 5V) I put onto the analogue inputs, it doesn’t affect the value I get on screen.

I am connecting a positive wire to the A1 terminal and a ground wire to the GND terminal. Have tried omitting the GND, and this has no effect.

I bought the kit ready assembled, so no problems on wiring. There are no resistors in R8 and R9, but I think these are just for varying gain?

What am I doing wrong? Why can I not read an analogue input?

Many thanks,

Frokoy.

2

Your K8055 board is now in test mode. Now it uses the internal +5V as the analogue input signal.
In the manual on p. 10 there is written:

[quote]The analogue inputs A1 and A2 have a standard range of 0 +5Vdc.
To use them externally, remove the jumper caps on SK2 and SK3.
The internal 5V voltage source can only be used for testing purposes.[/quote]
The solution is simple: Just remove the jumper caps on SK2 and SK3.

3

Amazing - thanks very much.