DAC PROBLEM on 16f877

jruibarroso · Joined: 07 Jan 2006 Posts: 64 Location: Braga

Is possible to use analogs ports to output 0 ..5 v on a PIC 16F877 ?

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley

No. The analog ports on 16F877 (and I think on the rest of the PICs to) are either analog inputs or digital I/O. However, aside from buying a separate DAC chip, you can build a cruide DAC out of a PWM output, a low-pass filter and feedback to the PIC's A/D. This technique has been discussed in this forum:

http://www.ccsinfo.com/forum/viewtopic.php?t=19899
http://centauri.ezy.net.au/~fastvid/picsound.htm

Eugeneo · Joined: 30 Aug 2005 Posts: 155 Location: Calgary, AB

Take a look at the Mchip TC1321
I used this quite a while ago but it worked great.

It's a 8 pin soic with a 12 bit res.
No opamp/fet required.
SPI

And you can set it up in about 1 hour

http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=11028&mid=11&lang=en&pageId=79