Probing breadboards - what do you use? - Page 1
Forum section: electronics / beginners

author: kalel
author_rank: Frequent Contributor
timestamp: July 19, 2017, 04:09:17 pm
content: What do you use to probe breadboards with a multimeter? Do you use clamps in combination with something like a dupont pin, do you have a pair of modified probes for your multimeter, or do you have such needles which are compatible with a breadboard on a multimeter probe already? Of course, any other possibility is good too, just interested in what people use to do that.

author: elecman14
author_rank: Unknown
timestamp: July 19, 2017, 04:19:52 pm
content: Typically use a mini grabber with a wire wrap pin like thishttp://www.ebay.com/itm/181575104901. The square pins keep the probes from twisting in the breadboard

author: MosherIV
author_rank: Super Contributor
timestamp: July 19, 2017, 04:39:38 pm
content: I made these cables, 4mm banana to mini grabbers for some of my dmmsI got them here (but you should be able to find them on ebay or whatever you main source of electronic components)https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=225_233&products_id=1724&zenid=rondm9l3f0t44nejieesmoear2]https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=225_233&products_id=1724&zenid=rondm9l3f0t44nejieesmoear2] https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=225_233&products_id=1724&zenid=rondm9l3f0t44nejieesmoear2Most circuits on breadboard or strip board should be low voltage or low current so safety is less of an issue, so you can get away with cheap home made stuff

author: alm
author_rank: Super Contributor
timestamp: July 19, 2017, 04:41:28 pm
content: I usually bend a cut-off axial resistor lead in a U shape with ~0.1" pitch so it fits in two adjacent holes. Then I hook a grabber to it. I find this more stable than a single pin, and nicer to the breadboard than forcing0.0630.025" pins in. But sometimes they still pull out, especially the heaver scope probes. I have also usedright angle 0.1" headers(despite the forcing into breadboard issue) if I needed more pins.Some breadboards have binding posts that you can connect to the breadboard with wires. There are never enough binding posts to cover all test points, however.One thing you shouldnotdo is put a thin probe directly into a breadboard hole. I broke a (cheap) probe like that once.Edit: fixed mixed up units for 0.1" square pin diameter.

author: KL27x
author_rank: Super Contributor
timestamp: July 19, 2017, 11:12:02 pm
content: QuoteStandard pin 0.1" spaced pinheader pins are 0.025" square. This is fine on my breadboards. I just stick pin headers in the board and clip or touch my probes to the pins.In the past I have made special DMM probes with pin on the end. But sticking lone pin in a breadboard is sketchy. They wiggle and twist and don't have much stiction if you move things. Then I tried putting female pin socket on test leads. You can slip in a male pin if you need to make it a male probe. Or you can stick in on a male pin test point. But even these end up more trouble then they are worth. The scope probes and hook probes are fine, and I just work around those.QuoteIf you stick whole row of pin header in there, 3+ pins across 3 different busses, the friction is enough to prevent the up/down wiggle and you have access to all those busses. Buy why stop at 3? Often I stick large rows, pulling out every other pin to make more room for the scope probes. And then I build my circuit around those test points. This also eliminates ratsnest. You can wire wrap to these pins; the extra long pins are a plus.

author: jpanhalt
author_rank: Super Contributor
timestamp: July 19, 2017, 11:43:45 pm
content: I prefer the micrograbber to the "hook" version. Brand is E-Z hook or grabber. Probably several similar products available. It will easily attach to an SOIC chip pin and maybe smaller.I attache a "Dupont" type of female-male cable to it. I use "noodle" wire of about 24 to 22 AWG with PVC rather than the thicker silicone insulation. Makes it easy to probe pins, the 25-mil square male pin (as from a typical pin header)inserts in the BB easily, and so forth.John

author: Eric_the_EE
author_rank: Contributor
timestamp: July 20, 2017, 12:05:12 am
content: I invested in a pair of these fine-tip probes.https://www.digikey.com/product-detail/en/fluke-electronics/8845A-EFPT/614-1262-ND/1843900They do fit into breadboard openings, but what I actually use them most for is probing around PCBs with fine-pitched SMT components.

author: KL27x
author_rank: Super Contributor
timestamp: July 20, 2017, 12:49:26 am
content: The hooks are good, too. The micrograbbers fall off if you look at them wrong. They are fiddly little things. They are great for when you need to clip directly to the leg of an SOIC or SSOP/QFP chip and/or to get a very high density of connections. For logic analyzer or what not. This appears to be what they are designed to do. On a breadboard, you have easy, solid test connection wherever you want to stick a pin header, and DMM has only 1 probe and 1 ground. Micrograbbers are awesome, but they don't make hooks obsolete!

author: bson
author_rank: Unknown
timestamp: July 20, 2017, 04:39:07 am
content: I usually just stick an inch or so of wire into the breadboard and hook the probe to the wire.

author: alm
author_rank: Super Contributor
timestamp: July 20, 2017, 05:16:09 am
content: Quote from: KL27x on July 19, 2017, 11:12:02 pmYou are right, I mixed up units. 0.025" = 0.63 mm. The first datasheet for a solderless breadboard that I found (3M) specifies their breadboards up to 0.032" diameter leads, and a 0.025" square pin has a maximum diameter of 0.035". So still a tight fit. I can see enlarged holes in the plastic where I inserted 0.1" square headers in my (cheap) breadboard. 0.018" round pin headers do not have this problem, but you cannot easily pull pins out of them.Quote from: KL27x on July 19, 2017, 11:12:02 pmAs I already stated, a row of pin headers are just as stable, if not more. Definitely enough friction. But sometimes you want a test point somewhere between two components in an existing circuit, and you do not have the space to do what you suggest.Quote from: jpanhalt on July 19, 2017, 11:43:45 pmDefinitely agree for DIP, SOIC and smaller. However, I do not find them stable on larger pins like 25-mil square pins. There I still prefer the traditional hook style grabber. Obviously on square pins you can also directly use square pin female connectors. There are even banana and BNC cables terminated into square pin connectors.

author: bjcuizon
author_rank: Frequent Contributor
timestamp: July 20, 2017, 05:17:33 am
content: How about aligator to banana plug leads. Just stick some breadboard compatible wire in, clip the aligator clip on the other end of the wire and plug the banana plugs in your DMM.

author: sycho123321
author_rank: Regular Contributor
timestamp: July 20, 2017, 05:21:01 am
content: I just stick a component lead in and hook on an alligator clip. Probably not the best way since it's easy to short something out!

author: bjcuizon
author_rank: Frequent Contributor
timestamp: July 20, 2017, 05:25:00 am
content: Quote from: sycho123321 on July 20, 2017, 05:21:01 amYeah, me too sometimes...I'm just carefull when I do it or else...

author: KL27x
author_rank: Super Contributor
timestamp: July 20, 2017, 05:36:23 am
content: QuoteIf you're talking the machined round pin header.... that's cool. But square pin headers are cheap as chips, even in the extra long versions, and they take wire wrap, as well. The maximum dimension of 0.035" is never going to come into play as long as you don't use single pins, ever.QuoteI always have the space. You can fit 5-6 wire wrap connections onto a single extra long header pin. And I got them poking up everywhere. If I make a breadboard adaptor, it's got extra long header pins poking up.If I make a pin header cable for prototyping, it's with long header pins sticking out for probing and/or adding more connections.If I still need another connection, it's just a matter of pulling out a component, soldering a wire to it, and putting it back in. And wrapping the other end to a header pin.Rows of header pin test points are big part of my breadboard setup. I will set up the header pins and put some label tape down with the names of each signal. Then however else I build the circuit, I will route the signal to the header pin.If you buy another breadboard, stick with 3M or Global. Or Wish(er?). They will handle square header pins and still work with DIP IC legs, no problem.Sometimes when working with PCB's, I use the breadboard JUST as a place to stick header pins. I'll hot snot the breadboard and the pcb's to a backerboard. Or sometimes hotsnot pcb directly to the top of the breadboard.When I was busy hacking a Hakko 888 board, I had to get signals from both sides and to be able to see the display. What I did to prevent a bunch of flip and flop and broken wires evertime I want to get another signal is to glue a female header on the edge of the board, and route all the signals I wanted to see/alter to the header. And then I plug this into extra long male header pin on the breadboard, which provide plenty of space and stable base to wire wrap additional circuitry and to clip the scope probes. All nicely labeled. I should have took a pic. Was pretty slick. If I want to get an additional signal, I just unplug it and take it to the microscope. No wires, no scope probes to unclip and reclip. All the junk stays with the breadboard.

author: Brumby
author_rank: Unknown
timestamp: July 20, 2017, 07:25:17 am
content: For "one touch" test points - when you just want to briefly check a voltage or whatever - I will use a "U" shaped piece of component lead, as mentioned above. But for connections that are attached, I tend to go a different route....I picked up a pack of breadboard jumpers a while ago - and, for general use, I just use one of those inserted into the breadboard and attach a scope or hook probe to the free end. This takes all the leverage away from the breadboard that, for example, can come from a heavy scope lead that wants to go its own way.It's only if there are signal integrity issues that I would consider more direct connection with the wrangling involved.

author: KL27x
author_rank: Super Contributor
timestamp: July 20, 2017, 07:36:49 am
content: Partially wired up. Got the ICSP header (mostly wired up... see I'm missing one line, lol), all the power pins, the I2C and reset pins, and a couple LEDs for verification.Tweaking and adding to my I2C code.I have a header pin test point for everything.

author: Ian.M
author_rank: Super Contributor
timestamp: July 20, 2017, 07:39:47 am
content: I use short (3") flexible extension leads with a socket*to fit the meter's probe tips and a long square pin at the breadboard end with heatshrink over the socket and most of the pin. I've tried hook attachments for the probe direct on the component lead, but you then have to be careful not to dislodge the component lead. For momentary testpoints I'll stick in a square pin, and for scope probe ground clip points I'll use a loop of bare wire.* The contacts from a Molex disk drive power connector fit most meter probe tips.

author: KL27x
author_rank: Super Contributor
timestamp: July 20, 2017, 10:14:45 am
content: Cool trick on the Molex connector.I have made and lost way too many fancy little adaptors. I thought I could outsmart years of evolution, but it turns out that the stuff they give me by default actually works the best.. for me. When I need to DMM to the breadboard, I wrap kynar wire over the little groove they put in the tip of the DMM probes. I think that's why it's there, anyway. It takes more time to do... but only if I could find my adaptor when I needed it, lol. Looking for things and putting them away is way too big a problem for me.I need two of these i2c port expanders for this project. And I realized, why do I want to look at the mess? I did this one on the bottom. The top is just a label and the pins.