PICkit3 ICSP connector - Page 1
Forum section: electronics / general

author: PerranOak
author_rank: Frequent Contributor
timestamp: July 04, 2019, 01:52:36 pm
content: Hi,Is there a convenient connector to PCB that can be used for ICSP using a PICkit3 so that it can just plug in and out as required?Cheers.

author: MarkF
author_rank: Super Contributor
timestamp: July 04, 2019, 02:07:51 pm
content: Do you mean something like this right angle header (or search for a straight header):https://www.mouser.com/ProductDetail/Molex/22-12-2061?qs=%2Fha2pyFadugXB6YkraMeltVNFKXPGDWK8iXjEcJFfgk%3D

author: Ian.M
author_rank: Super Contributor
timestamp: July 04, 2019, 02:10:47 pm
content: No parts solution if you are designing the PCBs:http://www.tag-connect.com/pickit3Otherwise Microchip are fond of a bare SIL 6way 0.1" pitch rightangle header at the board edge on their demo boards, or you can use an extender lead made with Dupont pins in a six way housing at the PICkit 3 end and whatever you need to mate with at the PCB end. The sixth pin (Aux/LVP) is rarely used, so you can often get away with a five pin connector, but be <EXPLETIVE> careful to get it aligned correctly!Don't exceed 6" lead length or use screened cable or you may run into problems with higher speed devices (official max length is 10" but you need some margin for PCB trace length).*DON'T* try to use a four pin connector by omitting the power pin. Although its mostly possible to fool the software by telling it to supply power to the board at the same voltage, that makes the software assume it can control target power sequencing which affects the programming modes it can use

author: ggchab
author_rank: Frequent Contributor
timestamp: July 04, 2019, 02:12:16 pm
content: I am simply using a pin header with the 5 first lines of the PICKIT connector, starting with MCLR:

author: cv007
author_rank: Frequent Contributor
timestamp: July 04, 2019, 03:23:44 pm
content: For my Snap adapter, I use a 10 pin keyed idc-https://photos.app.goo.gl/HA7EgmibKAuhWsRN7Not exactly the greatest connector for the mcu side, as its relatively large, but they are easy to get, easy to make cables for (or get pre-made cables which are also cheap and easy to find and you may already have some). It is quite nice to have a keyed connector. It also can act as a normal 5 pin header if needed with a 5pin cable or jumpers (although I have male on both ends, so is opposite of normal pickit/snap). Using an swd type connector would be the same but smaller, and maybe the prices of these things (and cables) are more normal by now (haven't checked).Maybe I'll have to make a little adapter for my pickit3 to convert to the same thing, as I dislike the non-keyed aspect as its too easy to get wrong- its like trying to plug in a usb device into a pc- it takes about 3 attempts before its right (at least with the usb you can't screw it up, you just attempt to do so a number of time).The inline header is nice because you can easily come up with a way to connect (bare wires if needed), but it is not so great when needing to connect to a number of devices frequently. You can also have an unpopulated/staggered 5/6pin header on the pcb, but then you are stuck using a cable with a 'live' male end and still have a 'polarity' problem . Or you just populate the male header on pcb, make up a male-female connector, clearly mark all pin 1's, glue the cable on the pickit side so it doesn't 'disappear', and be done

author: JPortici
author_rank: Super Contributor
timestamp: July 04, 2019, 03:47:25 pm
content: Here we use a 10 pin keyed IDC in order to provide power, target VDD, programming and UART.Also target VDD because we provide a loosely accurate +5V (USB VBUS) and the target MCU could run on a different supply. Target VDD connected to ICSP VDD.Hopefully in 10 years microchip will finally add an integrated uart on the new AUX pin in the pickit 4. Should have been done since day 1, but since we are not on day zero yet (decent part support)...

author: PerranOak
author_rank: Frequent Contributor
timestamp: July 04, 2019, 06:00:51 pm
content: Thanks all.I have used the normal right angled headers, etc. but I was thinking of something more like the "tag-connect" idea.I'd rather have, say, six (or five) pads on the PCB and just press (is this safe enough) a connector into them. This stands out less on the PCB; an edge connector looks a bit scruffy on a finished board.

author: Ian.M
author_rank: Super Contributor
timestamp: July 04, 2019, 06:11:27 pm
content: Another option is to put an edge connector on the board. Use a double sided edge connector socket (or at least one that doesn't have paired contacts for each pin on both sides of the board), and only put pads for it on one side of the board, and as long as its got at least one closed end or keying position there's minimal risk of misconnection.One cheap and cheerful compact solution would be to abuse a full size SD card connector, but that is less easy to key well.

author: MarkF
author_rank: Super Contributor
timestamp: July 04, 2019, 07:30:51 pm
content: http://www.2x4logic.com/tagconnect-pickit3.htmlhttps://www.digikey.com/products/en/development-boards-kits-programmers/accessories/783?k=Tag-ConnectYou have rich tastes.

author: MarkF
author_rank: Super Contributor
timestamp: July 04, 2019, 08:35:33 pm
content: Maybe you can make something from Pogo pins:https://www.amazon.com/pin-AVR-ICSP-Pogo-Adapter/dp/B075Q25BK3

author: PerranOak
author_rank: Frequent Contributor
timestamp: July 05, 2019, 11:24:00 am
content: Thank you.I did want a cheap solution to be honest. I had assumed that there would be something readily available and cheap as it seems like a thing that would be popular. Maybe I should have a go at the do-it-yourself idea.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: July 24, 2019, 03:47:21 am
content: I just use a 6 pin molex, they don't come much cheaper.However, after a few hundred uses the PICKIT3 connector starts to wear and become loose so maybe there is a better way.

author: Ian.M
author_rank: Super Contributor
timestamp: July 24, 2019, 06:02:43 am
content: Yes. *DON'T* directly mate the PICkit 3 with a pin header on the target board as that is certain to strain the female header on the PICkit 3 as it wobbles around, eventually causing unreliable contact. *ALWAYS* use an extension or adapter cablethat can flex without straining the connectors, and don't unplug the PICkit 3 end if you don't have to.However at the end of the day, the PICkit 3 is a cheap development programmer, so if you are using it in production, connector wear is likely to be an issue.

author: voltsandjolts
author_rank: Unknown
timestamp: July 24, 2019, 05:30:50 pm
content: I use 1.5mm pitch connection for ICSP with JST (Japan Solderless Terminals) ZB5B-ZR-SM4-TF connector.I have a simple adapter PCB to go from Microchip RJ12 6P6C to [0.1" header or] wires for the 5W JST connectorJST parts are:Farnell 2399302Farnell 2078162Farnell 1830898You would need the ENGINEER PA-09 tool for crimping the JST terminals.Just needs five ICSP pads on the target board, 0.55mm holes, 1mm pads, 1.5mm spacing. Connector stays in nicely even without soldering.

author: KL27x
author_rank: Super Contributor
timestamp: July 24, 2019, 08:45:25 pm
content: I make my own pogo pin adapter. There's no need for any fancy machining equipment.Make PCB, then solder the base of the pins flat against the pcb, sideways. You have a SIL pogo pin adapter. If you use two pads per pin with large empty space in the middle, you can much more easily get the pin straight/parallel before soldering the next one in place by walking one end at a time. Just edit your soldermask layer so you don't get soldermask under the middle of the pin. The shape of the soldermask can aid in keeping the pins parallel and in alignment, if you make it narrow enough.The best pogo pins are removable. The base is sold separately; it is a hollow sheath that the entire pin slides in/out, and this base is all you solder to the PCB. So you can easily replace worn/broken pins.You can even do DIL, if you want, using a double-sided PCB. I have done that, no problem. Use the datasheet to find the OD of the pogo pin base you are going to order, and add that to the thickness of the PCB for the spacing. By selecting the right thickness PCB you are close enough to perfection.I use 0.05" spacing. If you were to use 0.1", you don't really gain much over using plated thru holes for your ICSP (at least for a 2 sided board). The thru hole has the advantage that if you stagger the holes, you can stick a pin header in there, and it stays by itself. This is very desirable for dev or for large hex with long programming times.I'm really amazed. Been doing this for over a decade. And all I ever see regarding DIY interface is using CNC machined/drilled blocks with the pins stuck in, even for simple SIL footprints. Or some sad looking hotglue/epoxy blob to hold the pins. And of course a bunch of fragile fly wires soldered onto the ends. When you solder the pins to a PCB, you just route the signals to w/e connector you want, to fit to your PICKIT3 or w/e.Design the shape for holding in your hand, like a pen. And/or put mounting holes on it for w/e you are going to screw it to. EZ. If you need a pogo pin interface, you are designing a board you are planning to flash a lot of. Making a custom interface is a minor task, and you can reuse it for future projects.Q - Lack of permament connection sometime bending you into a pretzel? You have the one hand holding your ICSP connector in place while trying to hit a button on your keyboard/mouse?A - Does your programmer have a write button? Port that out and put a tac switch on your interface pen. It doesn't? Do you initiate a write/read with keystrokes? Then you can put a micro on there and program it to be a USB keyboard. Do you initiate read/write with a mouse click, maybe, thru a visual GUI? Put a micro on there to emulate a USB mouse. Or just buy a modern cheap USB mouse and take the chip out, and solder that to your interface along with a USB connector and w/e decoupling caps and pullups/downs you need to make the chip work.

author: NorthGuy
author_rank: Super Contributor
timestamp: July 25, 2019, 01:27:20 pm
content: Quote from: KL27x on July 24, 2019, 08:45:25 pmI solder pogo pins through hole. I use two parallel and identical PCBs spaced 1/4" to 1/2" apart, which results in a very sturdy construction whether it is used manually or as a part of automatic jig.

author: KL27x
author_rank: Super Contributor
timestamp: July 26, 2019, 01:04:39 am
content: ^That's good to know, for weird footprints in X and Y directions. It seems like the obvious way to do it. But I've only ever seen people stick the pins in a drilled block of MDF or plastic or whatnot. Not only just online, I've worked with other PCB designer who did it for simple SIL interface.* I've never had need for a complex pogo pin footprint; it's good to know it's as simple as this.The sideways method works fine for SIL interface. In over a decade, I have never broken one of these. Used in CNC machines, arbor presses, by hand, 10's of thousands of repetitions. This is ideal for a hand-held interface, because of the streamlined shape.It doesn't take a lot of force to depress a pogo pin. Not only I have never pulled a pin/pad off the interface, I've never had to replace a single pin due to damage or wear, at least not since upgrading from the cheapest pogo pins.*He actually outsourced these jobs, and this is what he received. His interfaces were machined some kind of resin cured MDF or something, drilled for the pins, and hand soldered flywires to a header. The custom arbor presses he provided our shared client was also made of the same material. They looked more or less exactly what you can buy on eBay for this task, if you search for testing jigs/arbor press. This is common enough there are apparently companies that make this stuff to order. I never cared to ask where he got any of this stuff made, because it was all over-complicated and stupid. OTOH, he asked a lot of questions and requested way to replicated a lot of my equipment, mostly diy and off the shelf stuff, easily adaptable/adjustable to different jobs.He wasn't too much of an engineer; mostly a businessman. He employed one high school grad across the country to do the PCB design, and he paid for the Altium license.CNC machining/drilling probably makes sense for a business that makes custom jigs, for minimal cost and turnaround time vs ordering one-off PCB.Edit: NorthGuy, I see from another thread, you tend to use plated thru holes in random layout for your pogo connections, and using low density, large diameter pins. The advantage of using pogo pins is you don't need thru holes. This alone negates much of the space advantage of random pad placement. And using a standardized footprint means you don't have to make new hardware interface for each project. I have used same footprint and interface for a variety of projects, and in one case I saved space by mixing up the pinout to cram it in there. Then just rewire the interface pen using the jumperpads I put there for that purpose.If you might ever need to support/maintain past projects, you will also end up with a collection of these large, bulky interfaces.And FYI, the teensy 0.05" pins are rock solid, if you buy the good ones.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 26, 2019, 03:03:58 pm
content: Just a note, I've found the PICkit3 rather unreliable for heavy use, and not just because of its connector. It would often have USB disconnections and/or become unrecognized by Microchip tools randomly and would sometimes require a complete OS reboot... so yeah. Maybe some have had better luck, but I'm not sure I would use it for production purposes.

author: NorthGuy
author_rank: Super Contributor
timestamp: July 26, 2019, 03:08:02 pm
content: Quote from: SiliconWizard on July 26, 2019, 03:03:58 pmRegardless, any ICSP programmer would require the same ICSP interface pins.

author: KL27x
author_rank: Super Contributor
timestamp: July 26, 2019, 11:26:49 pm
content: I imagine PK3 works perfectly for some folks. There are just so many bugs you never know what you're gonna get. I bet it works great on a Mac, lol.Personally, I have disconnection problems with ICD3. PK3 works fine for me when using the computer interface. It just makes me wanna commit suicide setting up the software every single time. And unfortunately, it constantly hangs on me (requiring reboot) when trying to use it in standalone mode.