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View Full Version : What's the next chip up from F627/8 for basic digilal I/O? Need a few more pins.



tekart
- 1st June 2015, 17:08
Most of the designs I have done recently have used the F627/8 chips using mostly digital I/O and one or two analog inputs, but now I need two or three more digital I/O pins and I'm trying to figure out which is the least expensive, simplest chip that just has a little more I/O. I am looking at the 16F631/677/685/689/690 series and these look like good cost/performance choices. Just wondering if anyone else has gone here before and has a preferred chip. It is so baffling drilling down through Digi-Key's search table. I don't want to go through the process of learning a whole new chip only to find it has limitations or issues.

My current project involves a custom-designed static LCD where I'm going to direct drive the segments from the port pins. So I am up 15 I/O pins (plus backplane drive) for the LCD and need the extra pins for user interface.

Archangel
- 1st June 2015, 22:00
16F648 - same as 628 but more memory & program space. 16F690 is my go to 20 pin pkg I bought microchip demo boards which hook up to pickit2 or 3 directly. Very easy to program and test on the fly.

tekart
- 1st June 2015, 23:22
Thanks, that is an interesting chip. Unusual power pin locations an general pin placement. I see why you like it and will keep it in mind.

I'm also considering the PIC16F882 as it's a bit cheaper and has plenty of extra I/O, it's overkill but works for this app.

Heckler
- 2nd June 2015, 02:54
I have used the following for a while...
8 pin 12F683
14 pin 16F688
20 pin 16F690
These were pretty much interchangable in terms of configs (8 pin used gpio instead of port)

Then instead of the 16F690 (4K memory, no Cap Sense inputs)
I switched to the 16F1828 (4K and Cap Sense)
and now I am using the 16F1829 (8k and Cap Sense)

Same 20 pin footprint and only a few config changes.

Ioannis
- 2nd June 2015, 07:52
You did not specified what memory requirements you have, so:

PIC16F527 at $0,46, 1,5K Flash
PIC16F1507 at $0,68, 3 Flash
PIC16F1578 at $0,70, 7K Flash

Ioannis

tekart
- 2nd June 2015, 18:20
Great feedback guys - thanks. I will look into the suggested chips.

Sometimes I wish Microchip would go retro and make some *really* basic chips with no fancy features, just s few A/Ds and all digital I/O with minimal configs. I'd use a bunch of them!

Ruben Pena
- 2nd June 2015, 21:43
Another chip you should like to try is the 16F723A.
Is pin compatible with the 16f882,28 pins,internal oscillator
and very cheap..
Greetings...
Ruben de la Pena.