Deglitching Micros on Plug-in Proto Boards

Yeah, I should do that. Stripping short chunks of wire-wrap wire is a nuisance.

I think we have some of that thermal-strip magnet wire around here somewhere. You could solder one end, solder the other with overhang, and trim with an x-acto knife.

--

John Larkin         Highland Technology, Inc 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

Den fredag den 29. august 2014 00.44.35 UTC+2 skrev John Larkin:

cutting before soldering is much easier, when you can touch the solder to freshly cut copper end it kinda sucks up under the enamel and burn it off very easy. It takes a lot more time and heat to do on the middle of a wire

-Lasse

I don't have much trouble with short pieces and I prefer Teflon insulation, anyway (expensive stuff though). I strip a length at least twice the bare wire I think I'm going to need, then attach that end. Then I strip a length of insulation the length of the "wire" and cut the wire so I have the length of bare wire needed to attach the other end. Works great for soldering or wire wrapping.

No one has yet suggested wire-wrap; it's good for higher frequencies than the best protoboards (which I've used at 5 MHz to good effect).

And, if you're paid by the hour, it's easy to rework when you make a mistake trying to remember mirror-image pinouts while looking at the bottom of the board!

Label the bottom of the board with the corner pins. Decades ago, when I did a lot of wire wrap, they sold plastic strips with the pin numbers printed on them, though you get used to working with the mirror image pretty quickly. A netlist helps. Schematics that use physical outlines, don't.

I've still got some GP wire wrap boards with power and ground planes connected to pins 8 and 16 of the 16 pin DIP pins installed. Now if I could just find something to plug into it... lol

What America needs is a good 16 pin DIP FPGA!

--

Rick

On a sunny day (Thu, 28 Aug 2014 20:27:43 -0400) it happened rickman wrote in :

hehe I once asked, when micro processors became more common, a budget for a microprocessor development system. It was denied. So I made my own processor with wirewrap as I had an 'unlimited' digital logic budget. A very educative project, worked very well too, and for sure RISC! After that micros were just the same thing over and over again.

Around year 2004 or so I threw all my old computah cards away. Including the 5/14 inch floppy drive, and 15625 Hz 80 colums monitor, and what not.

A different government will do.

I would ask how the hell you can turn an FPGA packaging problem into a government effectiveness problem, but I'm afraid you might tell me and my head would explode.

--

Rick

On a sunny day (Fri, 29 Aug 2014 03:17:41 -0400) it happened rickman wrote in :

Did not that explode a long time ago?

As to your desparate question related to religion What gov does goes. Create a politcal party that has as program 16 pin DIP FPGAs and you are already there.

From a saner pov (OK that may elude you) Latice makes some DIL FPGAs, but

16 pins less at least 2 power leaves only 14 (16 - 2 = 14 remember) pins for I and Ohhh Not very much, but OK lets say we do signal processing diff in and diff out Now we have 10 pins left, maybe for control or whatever. Yes, go for it (the politcal road).

Sank You Ferry Much

I usually just attach DIPs upside-down with Krazy Glue ("Dead bug" construction). The leads survive being bent down to solder to the ground plane, but only once, which is why I don't do it John's way--the unbent leads are much more robust. You can cut bits of copperclad with serrated aviation shears to make bus bars etc.

The other key piece of advice for good prototyping is to solder one wire at a time, rather than twisting a bunch together and soldering them all at once. Then (key step) *go back and reflow the joint at the other end*. That releases any spring tension in the wire, so that it stays put when you add more stuff.

You can do suprisingly dense things this way. Keeping the leads very short allows you to use the bodies of resistors and capacitors to force the leads apart and prevent them touching.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

I use #26 stranded wire with PVC insulation. It strips easily just using dikes, so it's a natural motion to cut and strip short pieces. For most things, though, you just use the scrap component leads that are littering the bench after the first few minutes.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

There's a pending EU directive to reduce the pin count of all ICs by

30%. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

I would settle for a good 16 pins micro. There are 28 pins AVR and PIC, but they are too long. I just need 2 pins for RX/TX and 6 I/Os. 16 pins DIP would be ideal.

I'm using 32-pin ARM M0s. They're QFP/QFN, rather than DIPs, however. I wouldn't have space for DIPs anyway. I don't remember the last time I used a DIP. It's gotta be close to 20 years, and they were leftovers from a decade before that.

They are good for preprogrammed chip shipped to the customer, so they can prototype/build their own PCB. There are 8 pins and 28 pins DIP AVR and 28 pins PIC, but nothing in between, unfortunately.

On a sunny day (Sat, 30 Aug 2014 12:22:46 -0400) it happened snipped-for-privacy@attt.bizz wrote in :

Mr Ming could use 2 8 pin PICs, use one as I/O expander via SPI.

but they are too long. I just need 2 pins for RX/TX and 6 I/Os. 16 pins DIP would be ideal.

yeh all the DIP has going for it is that it is easier to breadboard but wit h the numerous cheap devboards it is much easier to use one of those

-Lasse

C, but they are too long. I just need 2 pins for RX/TX and 6 I/Os. 16 pin s DIP would be ideal.

I wouldn't have space for DIPs anyway. I don't remember the last time I us ed a DIP. It's gotta be close to 20 years, and they were leftovers from a decade before that.

prototype/build their own PCB. There are 8 pins and 28 pins DIP AVR and 2

8 pins PIC, but nothing in between, unfortunately. 14 pin DIP,

no uart though so if you need one you'll have to use a sw uart

-Lasse

That would be two extra power & ground pins. At least two extra SPI Data/Clock pins from each chip. Not much left for actual I/Os.