ADC0804 or ADC0809

grindel

My dad was considering a web based volt meter for a remote solar powered camera project that he is involved with. I thought this was a great opportunity because I just got my propNIC working. unfortunately while researching ADCs I've gotten a little lost on the 2 pin version suggested in AN001 and didn't get the ADC0831 ordered in time to show it off while I was in town. Still hoping to get something thrown together this weekend that would function for this we headed down to the electronics shop and blindly bought ADC0804 and ADC0809. Only after getting them home and looking at the datasheets have a realized how out of my element I am. Are they just a multi-channel version of ADC0831 or is this a completely different animal?

Thanks for any help or advice, I might have to wait until the ADC0831 is delivered and I can use canned code.

JonnyMac

There's ADC0834 code in the Object Exchange: obex.parallax.com/objects/29/. I don't know if it works, but it's probably a good place to start.

TreeLab

As you've probably seen the ADC0909 is 8-way multiplexed. But the biggest difference (I think) is that the chips you have bougth are parallel interfaced, whereas the ADC0834 is serial interfaced. Different beast altogether, but since it is an 8-bit ADC, it should not be too tough to make work, but it will take a lot of pins from the prop.

I would stick with the serial i/o devices unless you are in a pinch. Plus, extending the ssytem to higher resolution (10 or 12 bits) is trivial with a serial interface, but a major headache with a parallel load chip.

Cheers!
Paul Rowntree

Scott Lewis

i took a look at the datasheet for your part and noticed there is no timing diagram, bummer. usually those are what i look at to make synchronous I/O such as this a/d work. To write your own program you will have to read the "functional description" section to understand how the thing works. The adc0831 code does work so when that comes you will be golden