PIC Tutorials - Going Equipped

[atferrari]

I posted before, thanking Nigel for the suggestion of using turned pins. Definitely, one of the most useful tips ever for me. I recall him saying he got it from somebody else. Not even dreamed to solder anything to them myself.

BTW, in maybe 15 years I am still using the same old protoboard (that is even the brand, I think) and I can recall just one micro (16F84A?) with a pin bent and subsequently broken many months later. The rest (many), they were honourably discarded after being carefuly burnt somehow. And in case you ask, no, never seen that famous magick smoke. Brave PICs!

 

[Nigel Goodwin]

I have soldered opposite corners of chip to socket to prevent chip coming out of socket, for the same reason .. .. if the chip fails .. then both chip and socket are consigned to the bin .. .. .. I think that is also being careful .. ... I suspect you are probably going to say OVER careful, but when you're as hamfisted as I am there is no such thing !

I would imagine the most 'dangerous' process here is soldering the top of the socket and PIC pins (as you're soldering FAR closer to the chip than is normal) - in my experience there's no chance of the chip coming out of the socket, you need a small screwdriver to lever then out

As long as you're happy, that's all that matters - but it's not really something that's required.

 

[Nigel Goodwin]

I posted before thanking Nigel for the suggestion of using turned pins. Definitely one of the most useful tips ever for me. I recall him saying he got it from somebody else.

It was from Don McKenzie at Dontronics in Australia.

I also thought it was a great idea

 

[JimB]

A variation on the "PIC in a socket" idea, which I came up with some years ago:



A turned pin socket for insertion into the usual breadboard, mounted on the socket were some turned pin SIL header strips, and built in to the whole assembly were the load capacitors for the crystal and the supply decoupling capacitor for the PIC.
Wire ended crystals (HC25) could be plugged into the end of the SIL strips, and HC18 type crystals could be plugged into the crystal socket.

This was all in the days of PIC 16F84.
These days I use 16F628 and 16F887 with a built in oscillator.
(Yes I know that there are newer types of PIC, but these are familiar friendly devices and I am comfortable with them for what I do.)

JimB

 

[Musicmanager]

I would imagine the most 'dangerous' process here is soldering the top of the socket and PIC pins (as you're soldering FAR closer to the chip than is normal) - in my experience there's no chance of the chip coming out of the socket, you need a small screwdriver to lever then out

Ah well, I hadn't thought of that one ! I just like things to stay where I put them !! I'm a bit of a b****r for that ! Maybe I should leave the solder out of the process, then everybody will be happy

I like JimB's idea of a PIC in a socket .. .. looks really good .. .. . along the same lines, if I stop soldering chips and sockets, maybe mine could be call a PIC in a Poke ?

D'you think ??

S

 

[Nigel Goodwin]

I like JimB's idea of a PIC in a socket .. .. looks really good .

But like he said, only in the distant past - mind you, not 'that' distant as he specified the later 16F84 and not the earlier 16C84

The built-in oscillators was a great idea, and was one of the features that triggered my tutorials.

 

[JimB]

not 'that' distant as he specified the later 16F84 and not the earlier 16C84

Probably did start with the "C" version, I transitioned to the "F" when they became available.

JimB

 

[Musicmanager]

I don't remember 16F84 or 16C84

The built-in oscillators was a great idea, and was one of the features that triggered my tutorials.

Oh, so actually JimB is to blame !! ?? Now there's a thing !

S

 

[MrAl]

Hi,

The machined pin sockets are great. I use them for the more important stuff.
I have never seen an IC chip fall out of a socket, no matter what kind of socket it was.
What i have seen though in some medical equipment was a pin somehow 'loosening' up, so that the IC pin does not contact the socket pin well enough for the required contact resistance. These were not machined pin sockets though, just the 'wipe' type sockets, and i cant remember if they were dual wipe or not unfortunately as this was back in the 1970's when 'regular family' TTL was still used all over the place.

 

[Inquisitive]

Good ol' Chip Creep as they used to say. Caused by heating and cooling as in turn on and get hot then cool when off.

 

[Nigel Goodwin]

Probably did start with the "C" version, I transitioned to the "F" when they became available.

I presumed you had

 

[MrAl]

Good ol' Chip Creep as they used to say. Caused by heating and cooling as in turn on and get hot then cool when off.

Hi,

Yes the thermal cycling probably eventually caused a break in the connection. These days i either use dual wipe or the machined pin type.
What happens i think is the IC pin stays relatively still while the socket contacts move out and then back, until one day they dont move back enough. Those units had quite a bit of heat inside too because for one thing they were made out of the original TTL series like the 7400 series not the more modern 74LS00 or similar.

 

[Mike - K8LH]

Another point of failure which I've seen many many times is oxidation of the IC pins and/or the socket wipers. Often simply pulling the IC and re-seating it in the socket will restore device operation...

 

[Nigel Goodwin]

Another point of failure which I've seen many many times is oxidation of the IC pins and/or the socket wipers. Often simply pulling the IC and re-seating it in the socket will restore device operation...

A small 'squirt' of WD-40 along the socket helps as well

 

[be80be]

Heck I've broke a pin or two off trying to get a IC out of a socket. I always seemed the ic puller was never around and they was 64 pin chips.

 

[Musicmanager]

A small 'squirt'

I know, but I'm quite likeable when you get to know me

By an IC Puller .. do you mean one of these ?

S

 

[granddad]

MM don't buy one I have a spare ?

 

[Musicmanager]

Hi GD

It's OK, I have two of those .. ..

.. .. .. . when they made me, they were out of stock of fingers, they used Sainsburys pork sausages ! Therefore, essential equipment !

S

 

[Mikebits]

I know, but I'm quite likeable when you get to know me

By an IC Puller .. do you mean one of these ?View attachment 95330

S

Your wasting your talents on electronics my friend, you need a microphone and a audience.

 

[granddad]

MM think you will find the puller shown above is for PLCC sockets... GD