Suitable replacement for a PIC16C57-XT/P

[rogerw]

I had some great help in another thread yesterday, so thought I'd ask a burning question that I've often wondered about but never got around to researching.

Some of the gear I repair use PIC16C57-XT/P chips. I am finding them harder to buy off the shelf ... and have not been all that thrilled with some of the cheapies I've bought from Hong Kong ... counterfeits???

Anyway, can anyone tell me confidently whether there are any other Microchip PIC's that can be used in their place without having to modify the code etc?

Thank you.

 

[Ian Rogers]

Non standard pin layout!!! I haven't seen a chip like it!!!

I would have a dip to dip adapter made and use a pic16f886... But!! The code will have to be modified!!! "C " derivatives will be harder and harder to get hold of... The newer "F" chip layouts are more readily available..

But!! Just try a PIC16F57 and see if the hex file will work straight off the bat!! They are only 70 pence each!!

 

[Nigel Goodwin]

I would imagine you're going to have to modify the code, but probably only very slightly - don't you have the source code?.

It's rare for later chips to be HEX compatible with earlier ones, simply reassembling with the correct header 'might' be all that's required, but slight source changes might be as well - MicroChip often publish 'upgrade data sheets' which list the minor changes required.

But why do you need processors for 'repairs'?, it's extremely rare to see a processor fail.

 

[rogerw]

But!! Just try a PIC16F57 and see if the hex file will work straight off the bat!! They are only 70 pence each!!

I have bought a tube of them and am going to do some experimenting, I just hadn't got around to it yet.

I hadn't given it a lot of thought as the adaptor is likely to cost more than a genuine pic ... but the later version of the board does use a tiny little smd PIC16F57-I/SS ... and definitely uses the same code ... though I may have to reconsider if stocks do run out.

 

[rogerw]

I would imagine you're going to have to modify the code, but probably only very slightly - don't you have the source code?.

Yes I do ... but I'm not sure I'm confident enough to know that I've made the right changes.

It's rare for later chips to be HEX compatible with earlier ones, simply reassembling with the correct header 'might' be all that's required, but slight source changes might be as well - MicroChip often publish 'upgrade data sheets' which list the minor changes required.

From my experience with the later boards using the PIC16F57-I/SS ... I do use the same HEX code ... but obviously set up the programming for the smd chip ... so maybe I'm answering my own question.

So I should try a PIC16F57 as above ... just making sure to set up the parameters for it in the programming stage. Like Ian said ... they're cheap ... I only paid $0.79 AUD for them (genuine). I will have a good read of the datasheet though first ... in case there are some glaring issues to be dealt with.

But why do you need processors for 'repairs'?, it's extremely rare to see a processor fail.

Maybe for you ...

Here's just a few I've changed lately. Wanna see some more?

 

[Nigel Goodwin]

There's something nasty happening then - something is obviously killing the chips - and PIC's are so hardy and reliable it's got to be something REALLY nasty

I've still got a fully working PIC with my fingerprint burnt in the top - best not to plug then in the wrong way round!(and if you do, then don't feel if it's getting hot without licking your finger!).

 

[rogerw]

There's something nasty happening then - something is obviously killing the chips - and PIC's are so hardy and reliable it's got to be something REALLY nasty

Yes, I agree. I don't know what causes the failures in most cases, but despite the number I've shown ... they are extremely reliable.

There are occasions where one of the mosfets that the micro drives, is s/cct ... and that can kill the micro if left on too long ... but the majority I don't know.

They live in a fairly hostile environment and so some failures are probably moisture related, though they are pretty well coated ...

and at the same time ... a similar board from another manufacturer which also uses a PIC16C57 but in a socket and has very little protection ... occasionally come in with pins almost eaten through and yet the micro is still fine.

I was being a smart alec by the way ... sorry ... that collection is from a couple years. Not sure why I kept them ... but there you are.

I've still got a fully working PIC with my fingerprint burnt in the top - best not to plug then in the wrong way round!(and if you do, then don't feel if it's getting hot without licking your finger!).

Ouch!! ... I know it probably wasn't funny at the time, but I got a laugh out of that ... thanks.

 

[rogerw]

I realise this thread is a few years old, but I came across it again the other day and thought I should give an update.


My initial question was whether a replacement was available for the PIC16C57 micro as they are getting harder to buy, and more expensive.


The suggestion was to try some PIC16F57’s and so eventually I went through the process of trying them out.


I need them to replace failed micros on a particular type of board, so I used one of the boards as a programmer/test board.


I fitted a ZIF socket for the micro and 5 additional wires to plug into the PICKit3 programmer.

Ground, 5 volts, MCLR/VPP (pin 28), Clk (pin 16), Data (pin 17)


Then - open up MPLAB and select PIC16F57

Set Configuration Bits - Osc Type - Watch Dog Timer - Code Protection

Load the original hex used on the PIC16C57

Connect the PICKit3 to my board

Power up the board and hit program


A few seconds later it’s programmed and the board lights up – and I can put it through it’s paces to make sure it does what it’s supposed to do – then plug in the next one and repeat.


I can do a whole tube of micros in 30 minutes or so – program and test.


Each time I do a batch, it never ceases to amaze me that it’s as simple as it is.


I’m sure someone will tell me it doesn’t work like that or I’m doing something wrong – but I’ve probably fitted 50 or 60 of them so far with zero issues.

 

[Ian Rogers]

Nope!! That's how its done... It's called OTG ( on the go ) programming..

I'm glad it all worked out for you... Thanks for the update.