Which PICs to buy ?

[AndrewC]

It is embarrassingly difficult to get small numbers of PICs over here. I've got a tube full of 16f628A but I've got a couple of projects that need something different - something from the 16F7x7 family because I want three hardware PWMs and then a 16C782 because I want the switch mode driver.

I can buy these from microchip direct but shipping is ludicrous for just a couple of chips even if I buy some spares in case of "accidents". Any suggestions on some stalwarts I could buy to build my order up ? I know it's difficult because I've no idea what I might use them for but if anyone has got any recommendations I'd be interested to hear - or even alternatives to the 16F7x7 and 16C782.

Thanks, Andrew

[skimask]

In addition to what you 'NEED', what you might want (IMO):
For playing around with maximum options:
PIC18F4685 (96K, CAN, 40Mhz, etc.)
PIC18F4550 (32K, USB, 48Mhz, etc.)
Replace the 4 (40 pin type) with a 2 for a 28pin version.
PIC18F1320 (18 pin, still an 18F type, 40Mhz)
PIC16F887 (40 pin 'old school')

For playing around with the small ones:
12F683 (8 pin), 10F222 (6 pin), 16F88 (18 pin), 16F777

But that's just my toolbox. Others obviously have different preferences. I don't think I've got anything else in there. I've given away all of my older stock (16F84A, '877A, 18F452, 18F4620). Nothing wrong with any of those, except the newer ones have more options.

[Archangel]

In addition to what you 'NEED', what you might want (IMO):
For playing around with maximum options:
PIC18F4685 (96K, CAN, 40Mhz, etc.)
PIC18F4550 (32K, USB, 48Mhz, etc.)
Replace the 4 (40 pin type) with a 2 for a 28pin version.
PIC18F1320 (18 pin, still an 18F type, 40Mhz)
PIC16F887 (40 pin 'old school')

For playing around with the small ones:
12F683 (8 pin), 10F222 (6 pin), 16F88 (18 pin), 16F777

But that's just my toolbox. Others obviously have different preferences. I don't think I've got anything else in there. I've given away all of my older stock (16F84A, '877A, 18F452, 18F4620). Nothing wrong with any of those, except the newer ones have more options.

And opinions being like ex wives, you may have more than 1 Hi Andrew, Ski, I like 16F648A as a replacement for 16F628A, same chip with 2X the memory and cheaper now too, get some of the cheapies like 12F675 for little projects not involving driving LCDs , as for OLD SCHOOL, well old school is usually (not always) easier for beginners to get working. Let me Re Define, Beginner as someone still LOST in a data sheet, someone who is still convinced it would be easier to do word style math problems in Japanese than make sense of register settings

[skimask]

And opinions being like ex wives, you may have more than 1

And if I spend any more time messing around in my lab, I just might increase that particular number by one myself!

Hi Andrew, Ski, I like 16F648A as a replacement for 16F628A, same chip with 2X the memory and cheaper now too,

That's why I mentioned the 16F88 types. Newer than the '628A, a few more options, basically the same chip. And you only get the 'new' stuff if you try (oscillator options, stuff that's buried in the datasheet)...other than that, operates the same way

as for OLD SCHOOL, well old school is usually (not always) easier for beginners to get working. Let me Re Define, Beginner as someone still LOST in a data sheet, someone who is still convinced it would be easier to do word style math problems in Japanese than make sense of register settings

Yes, true, but like the 'F88, the 'new' options are buried and not necessarily used by a 'beginner', but they are always handy to have when a person doesn't know they need them!
Then again, I just might be talking about future-proofing ones self

[AndrewC]

Thanks guys - just the inputs I needed

Andrew

[mackrackit]

You may want to consider a serial eeprom too when you are ordering.

I will not make a part number recommendation though, I have not used enough to know all of the differences.

[tenaja]

if you are just hobbying, then I would choose the most feature-laden PICs in each pin size, within reason. The 16F88 is a pretty decent chip (I've used it), but the 18F1320 is very similar and the code compiles more compactly. The 16F688 is pretty cheap considering its specs, with a few pins less. For 40 pins, although you could use a 16F887, but the 18F45k20 has more memory for a couple pennies more.

What I've found works for me is to prototype with a 40-pin, then convert it to a smaller device. Some of the new 18F k-parts are cheaper than the 16F parts, and since the code compiles smaller it's almost like getting a second discount. Here are some devices that I'd recommend in pin various sizes. Most folks are intimidated by the 18F parts because the datasheets are longer, but once you can understand the basics behind reading a datasheet--and especially if you can learn one series--it gets a lot easier. It is the "series" thing that I like to stick to, when possible, to reduce learning curve. Here's my list, with two basic series for the larger devices. Note, too, that the newer chips tend to be more powerful and less expensive than the older ones. The m'chip site has a good search tool, but the one on melabs.com has a few things that mchips doesn't--such as a/d resolution.

8 pins; 12F683 (the most for its size)
13 pins; 16F688 (cheap)
18 pins; 16F883 (cheap)
18 pins; 18F1320 (powerful and cheap)
28 pins; 16F886 (cheap)
28 pins; 18F25K20 (powerful and cheap)
40 pins; 16F887 (cheap)
40 pins; 18F45k20 (powerful and cheap)

[AndrewC]

more food for thought - thanks

From a hobby point of view it does make sense to stick with a one series and use a power packed chip even if you just take it for a walk around the block.

[skimask]

13 pins; 16F688 (cheap)

A little bit rough on the PICs aren't ya?

[nomad]

Don't forget microchips sample program!

[tenaja]

A little bit rough on the PICs aren't ya?

I guess so! I gave that one the 3 with my middle finger instead of a proper 4 with my index. Hmmm....maybe a Freudian slip.

Well, maybe not... I have not had any bad experiences with the 14 pin 16F688.