What do you use - prototyping.

[BenKenobi]

What do people here use for prototyping circuits on a 'temporary' bench lash up.

I have a variety of 'breadboards' some are decent, others are fit only to stop the table rocking or door closing, same goes for the jumper cables. Is their a gold standard in these things - it seems very hit and miss. I've got one really nice one  but the contacts in it seem to be going loose and I can't remember where I got it, looks like this

http://www.ebay.co.uk/itm/5X-2860-tie-point-solderless-breadboard-Including-jumper-wire-S-/172881587757?hash=item28408bae2d:g:QqwAAOSwOudZxmTv

It's really good because I can put voltage into it from different power sources this lets me mix n match my 5V devices and my 3.3V devices. At some point I guess I'll want to be converting prototypes into PCB designs but I'm a bit clueless on that score at the minute.

And what do you use in terms of test points, I'd like to use some sort of pin but have yet to find one that works, I usually use a jumper cable but this can be unreliable and its messy.

I'm looking for ways to work on projects, build them up then put a lid on them and move onto another without breaking them down so that I can come back to them (I tend to break projects down into smaller project sections and then combine), I also want a tidy way to add test points.

[Yansi]

It very depends on the exact job to be done. Some circuits can be breadboarded, some are better to be soldered on the veroboard (typically higher voltages and/or currents). Some circuits can be rapid prototyped using a piece of copper clad board where you mill out some squares for the solder joints. Some circuits cannot be tested without properly etched bords (RF, microwave).

I use all of these above.

[Benta]

I never use solderless breadboard. Far too much effort troubleshooting due to bad contacts, bad routing etc.
I use 90% veroboard or 10% air mockup, always soldered.

[BenKenobi]

I don't do a lot of high frequency stuff but I am experiencing the shortcomings in breadboard use, I find the soldering up of stuff a hassle - and I always muck it up.

I marvel at how tidy some people seem able to work but I have problems transferring schematic to reality so I tend to breadboard a lot.

I have used Vero but I find the copper tracks very limiting and end up cutting tracks and putting jumpers all over the place and it is useless for anything with an IC or two, I've had some that wouldn't take solder readily.

As you say reliable contacts on breadboard are really challenging and utterly useless for anything with digital communication.

Just looking for a reliable cost effective method, I've searched and searched for different methods and come up empty.

[Benta]

I have used Vero but I find the copper tracks very limiting and end up cutting tracks and putting jumpers all over the place and it is useless for anything with an IC or two, I've had some that wouldn't take solder readily.

When I say Veroboard, I don't use the ones with continuous tracks, but rather with individual solder pads or with IC layout and 3-hole strips from each IC pin. Works great for me.

[tggzzz]

If you use modern logic, are you so sure you don't have high frequencies? Calculate the di/dt when switching, and calculate the voltage drop across a wire; assume 1nH/mm. Consider 74lvc, which has sub-nanosecond risetimes, and significant energy above 700MHz and even 1GHz.

See Jim William's AN47 - easily findable via google.

Other search terms: manhattan, pittsburgh, island, dead-bug, live-bug. Any of those is better than solderless breadboards.

[BenKenobi]

Even on a quick scan that 'AN47' looks like a really interesting doc - and I thought my breadboarding was untidy - but I do get the concept of why ( I think ) , I'm starting to think that just buying an oscilloscope (not even got it yet) is going to confirm that my circuits are likely sound but my test reg construction isn't - perhaps the device isn't the defect after all.

I definitely need to work on my prototyping ...

[bd139]

I've built a frequency counter which was good to 35MHz on a breadboard. It depends what you're doing, how fast it's going, where signals are routed etc. The input stage was not on the board and was dead bug. The first counter and gate was on the board. Signals slightly ugly but it worked.

I actually build quite a few things on solderless boards first to see if they work first before I invest in throwing the parts in the bin if they don't work. Yes they have problems, yes they change circuit characteristics slightly, but at the low end of the frequency spectrum it makes little difference, say under a couple of MHz. Reliability isn't a big problem unless you buy crappy boards or keep them for a long time.

Recently I built a very narrow 600Hz CW audio filter to add to a receiver. The whole thing started off as a total mess on a breadboard:



Evolved into an even large three pole tangled mess. Eventually it pops out the other end looking relatively decent:



The above is actually stripboard, not padboard/matrix board. Plan was to build it with low spec parts and see if I can get it in spec. 603Hz centre frequency, Q of 11 and 1.8dB of gain at the centre = win.

[BenKenobi]

And the prototype became the final ...

So how do you define a good board from a bad one, as I said I've got some that look fine but I only use them to keep the door open ..

Who makes the good stuff in terms of track cutters for Vero - mine seem fine for a couple of holes then I get the Dremel out ... who makes good Vero, good breadboards, good interconnect cables etc.

I even bought the tools to make my own cables, crimps, pins, various headers but for the life of me I can't get the hang of that - I destroy more pins than I make successfully.

[bd139]

Here's my recipe:

Good boards: Wisher, 3M. That's it. All the other vendors are crap. There's a thread here where we go into detail about good ones and crap ones: https://www.eevblog.com/forum/chat/breadboard-maintenance-tips/ - main thing is you have to throw them away sometimes.

Track cutters: If I want a compact layout I'll use an x-acto knife to break the traces by hand. If I am not too bothered I'll use a 5mm hss drill bit with a bit of insulation tape around it. The track cutters you get tend to dig holes too deep when you just want to cut the copper.

Good vero boards: I use Roth Electronik ones from RS. They are FR4 (glass fibre) substrate with tinned copper. Not crappy paper boards that aren't tinned. http://uk.rs-online.com/web/p/stripboards/5185932/

Good jump wires: I make my own. I buy 22 AWG wire from Tayda Electronics here http://www.taydaelectronics.com/hardware/cable-wire/awg-22-red-hook-up-wire-1ft-30cm-solid.html (it's really good!) and some T-strippers (these are expensive but worth it): http://uk.rs-online.com/web/p/cable-strippers/0243112/

I use the Molex connectors here for board interconnects: http://www.taydaelectronics.com/connectors-sockets/wafer-housing-crimp-terminal/serie-2500-2-54mm.html ... crimped with some crappy pliers from Machine Mart. No funky tools required really. They may or may not be genuine Molex but at that price they represent very good value for money.

Note Tayda takes a couple of weeks to turn up but they're generally better value than the local suppliers here in the UK.

[BenKenobi]

All good stuff, it is clear that prototyping isn't necessarily a pretty business ..

[tggzzz]

I'm starting to think that just buying an oscilloscope (not even got it yet) is going to confirm that my circuits are likely sound but my test reg construction isn't - perhaps the device isn't the defect after all.

Be aware that scope probes are part of the circuit; FFI, see https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/

AN47 is a classic; you will see repeated references to it. Make sure you read the appendices.

[bd139]

Agree with AN47.

Also this is a gem, even though it’s 1960s vintage: https://youtu.be/ACUbBUydgUQ

[BenKenobi]

Be aware that scope probes are part of the circuit

I know - scarily so, working out just how much they influence it is frankly beyond me right now. The real irony here is that 'studying' what I needed in an Oscilloscope and how to use an Oscilloscope has me reading so much stuff that I'd not even considered - remember I'm a computer science type not an electronics type. Although I already understand many of the concepts as the majority of my work is based in the real time world so being able to measure and detect things without the presence of the tester affecting the outcome of the test is always a challenge - and not only with scope probes.

I find it somewhat intimidating, I knew I had to have good joints and connections, I know a fair bit about EMC and such, but actually seeing the extent to which this can go is insane - some of the probe leads cost as much as the scope !!!!  - I'll never be able to justify that no matter how 'correct' it is, how far is too far for an amateur.

I posted a link to this vid on another thread - just a simple wire NOT 

[Howardlong]

Coincidentally I did a video today about the breadboard and prototyping methods that I use which should be up in the next couple of hours (uploading now *** Sorry, I had to re-upload, something went wrong with the transcoding ***).

https://youtu.be/5Og9MUkIeHk

I use several methods, depending on the circuit. Even if the end result will be on a custom PCB, I do a lot of unit testing using the various techniques before designing and committing a complete design to a board house.

Solderless breadboards, certainly, I use them all the time, together with breakouts for SMDs. I agree with others, there are some crap ones out there. Somewhat counter-intuitively, I get mine from Maplin here in the UK, they are pretty reasonable compared to some of the cheapo crap on ebay and Amazon. I do buy the link wires from Amazon in bulk, they're not the best but they're good enough usually.

For most breakout boards for standard SMDs like SOIC/TSSOP/MSOP/QFN/QFP/SOT23 etc I go to ebay and buy in bulk and keep a reasonable stock as not a day passes without me using one or two.

For some more SMD stuff like sensitive analogue and mixed signal, I use Schmartboards which have an integrated ground plane mitigating many effects that breadboarding suffers.

Some breakouts for BGAs and slightly more exotic packages are available from Proto-Advantage, but they don't have the ground plane that Schmartboards do.

For basic soldering, I've used veroboard, particularly Tripad, for decades and continue to do so, and I mount a hybrid of both through hole and discrete SMD parts on them.

More recently after a post a few months ago here, I have started using BusBoard SMTpads surface mount boards with solid copper groundplanes and holes for optional ground vias. These are free-form like veroboard and better support things like switch mode power supplies and some analog and mixed signal stuff thanks to their solid ground planes. They're available in both 0.1" pads and 0.05" pads.

If all else fails, I make up a board and fab it myself in-house. Making the board itself is quick once you have figured out your process (figuring out the process takes a lot of failure though!), half an hour from opening the cupboard with the nasty chemicals to having a board and tidied up. For anything other than a really basic board, laying out the board typically takes quite a bit longer, as I capture the schematic at the same time (most of my designs live through their prototyping life on paper).

If I do make up the board myself, I can go down to 0.5mm pitch reliably, but I am unable to drill vias under 0.7mm without breaking drill bits, that may be my crappy drill press though, but it was advertised as being specifically for PCB drilling. Thankfully I do little through-hole on my own board layouts and usually maintain a solid ground plane on the underside so drilling is typically limited to ground vias.

Some links:
http://www.busboard.com/surfacemountpcbs
http://www.proto-advantage.com/store/index.php?cPath=4000
http://schmartboard.com/surface-mount-boards/

[BenKenobi]

I was wondering about how to handle surface mount packages. Wouldn't it be so cool if you could just print your PCB on something akin to a 3D printer - gee should I patent that idea ...

[Howardlong]

I was wondering about how to handle surface mount packages. Wouldn't it be so cool if you could just print your PCB on something akin to a 3D printer - gee should I patent that idea ...

Breakout boards.

Someone did a PCB printer, or at least talked about it. Not sure it this was the one. $3.5k, eeeek.

https://www.voltera.io/

[BenKenobi]

Is it that the PCB's aren't generic enough or that packages aren't made with any 'consistency', as for the printer I don't think at 3.5k I'll be buying one any time soon.

[kalel]

Conductive ink printer could be an interesting thing at a low price (if the technology is useful, prices might come down eventually).

Still, it mentions:

~5 USD
Board cost.

I'm not sure how this compares with the cheapest Chinese fab house (for those that can wait up to a few weeks), but I understand that even more expensive - but rapid - could be worth a lot for some people in some cases. I don't even know much much the current home etching methods cost per board.

[tggzzz]

- some of the probe leads cost as much as the scope !!!!

A quick scan of a mass market distie shows £5230+VAT, and that's far from the most expensive! http://uk.farnell.com/tektronix/p6248/probe-oscilloscope/dp/4352610

Concentrate on bog-standard 10* "high" impedance probes (preferably with a short ground connection), *1 probes for low-level signals, *10 resistive divider "low" impedance Z0 probes, ignore *1/*10 switchable (because you will accidentally move the switch, sooner rather than later). For high voltages (i.e. >50V) get a decent HV differential probe. And watch the max voltage vs frequency rating very carefully.

[BenKenobi]

  £5230+VAT 

Where do you keep them in a safe - I'm forever losing stuff like this without even leaving my man cave ... now where did I put that wire coat hanger - that'll do the job ...

[Avacee]

I was wondering about how to handle surface mount packages.

I find these SMD to DIP adapters are a godsend for prototyping onto either vero/strip/bread/etc board.
http://www.ebay.co.uk/itm/20PCS-SOP14-SSOP14-TSSOP14-to-DIP-PCB-SMD-DIP-Adapter-plate-Pitch-0-65-1-27mm-AS-/291979406901

There are adapters for each of the pin counts - this link shows the 14 pin version.
One side is 1.27mm and the other is 0.65mm and if you don't suck at de-soldering you can reuse your expensive IC on your final PCB.

[tggzzz]

£5230+VAT 

Where do you keep them in a safe - I'm forever losing stuff like this without even leaving my man cave ... now where did I put that wire coat hanger - that'll do the job ...

Pah. That's low cost.

Consider "P7700 series TriMode probes are available for order now worldwide. Probe prices start at $8,500.  A set of 5 TekFlex solder tips is available for $250". Why do they come in 5-packs? ISTR each tip has a guaranteed lifetime of 10 touches. Yup $5 every time you touch a node.
http://news.tektronix.com/2016-03-15-New-Performance-Oscilloscope-Probes-Tackle-Todays-Smaller-Faster-Designs

[Howardlong]

Conductive ink printer could be an interesting thing at a low price (if the technology is useful, prices might come down eventually).

Still, it mentions:

~5 USD
Board cost.

I'm not sure how this compares with the cheapest Chinese fab house (for those that can wait up to a few weeks), but I understand that even more expensive - but rapid - could be worth a lot for some people in some cases. I don't even know much much the current home etching methods cost per board.

I am not sure how the process is better than "home etching" from an ease-of-use or productivity perspective.

Home etching costs peanuts, but you do have to make the effort to get your process to work, and expect plenty of failures to get to that process, just make sure you document what works, and possibly more importantly what doesn't. Keeping to the same recipe is an extraordinarily good idea. Using different stock, in particular changing you pre-sensitised boards, or chemical mix/dilution, is not a good idea. I do my own etching sporadically, I can go weeks without needing to do a quick board then suddenly I might do a dozen in a couple of days, but it took quite some weeks if not months to get my process to work.

For the avoidance of doubt, my process very closely follows Mike's (http://www.electricstuff.co.uk/pcbs.html), but I "discovered" it without prior knowledge, I just did self-learning. What is nonsense and a waste of money for kitchen table etching are bubble tanks. Use your eyes and learn, bubble tanks will just get in the way. Plastic take-away containers are designed for the purpose ;-)

As a tool, what is very useful for any prototyping is a decent PCB guillotine, and while they're not cheap, my they're handy, way more useful than any bubble tank.

[BenKenobi]

Used to do a similar thing when I had a darkroom - digital is so much less hassle.