PORTS Forum

Ports and Interfaces => Parallel Port => Topic started by: montego on November 14, 2012, 01:21:01 am

Title: adc0809 connected to parallel port
Post by: montego on November 14, 2012, 01:21:01 am

Dear Sir

I am trying to build the ADC0809 circuit in you book Parallel port complete. I only read a value of Fff for each channel. Do yo have any suggestions of what the problem may be ?

The input is 0-5V to pin 1.
My PC system is a Pentium Dual core, using VB2005

I have used your original program and imported it into VB2005.

Could the speed of the PC system play any influence ?

If I change the program just to read one channelnumber, for instance channel 1, only channel 1 give a value of Fff. The other 7 channels show 0.

Thanks for you feedback.

Title: Re: adc0809 connected to parallel port
Post by: Jan Axelson on November 14, 2012, 11:43:04 am

To isolate the problem, use a voltmeter or 'scope to monitor the voltages on the pins. Use single-stepping to step through the program.