Generic FTDI in-circuit programming cable?

dmaxben

Member
Has anyone used any generic FTDI USB-RS232 cables in place of the traditional AXE027?

Im looking at a more compact header design for doing in-circuit-programming on my projects, and found this http://www.tag-connect.com/TC2030-FTDI

Looks like a nice setup, with the pogo pins and tooless/solderless clip attachment.

Would it work properly with PICAXE? Sorry for the potentially stupid question...I wasnt sure if there was something else "special" inside the AXE027...

Ben
 

premelec

Senior Member
My experience with USB -> RS232 cables is some work some don't... I've had good results recently with CH340 ebay boards that are pretty compact but don't have specific site I bought from... I suppose some of the chips are knockoffs that aren't up to full standards...
 

hippy

Technical Support
Staff member
That cable should work presuming the polarity can be reprogrammed.

At $69, and with the complexity of having to add suitable pads and alignment holes for the lead to every board, it might be an alternative to use a 3-way pin header on the board and create a flying lead adapter for a standard AXE027.
 

nick12ab

Senior Member
No reason why it shouldn't work, and at that price there should be no reason why they would willfully use fake FTDI chips

You might be able to get one for free with little effort if you can get the Easy-PC footprints to work in DesignSpark PCB, or can create a new footprint for any such program they don't already have one for.

The choice of legs or no legs has to be made at the time of purchase (they cannot be temporarily removed). The no-legs version would have to be held on the board by hand for the duration of the download, though there's a clip to hold it on which may or may not work very well (no idea). The legged version is more fiddly to insert than the non-legged version and the bendy plastic legs (no posh hinges!) are pressed inwards to remove the connector.

For one-off projects, I don't think this is a good solution. The main attraction is not having to buy a PCB connector, which isn't really relevant to hobbyist projects.

Another solution to consider is to use an AXE029, which will allow you to use just one resistor for the download circuit and requires a 3 or 4-pin 0.1" pitch header. A socket can be mounted on the board, or just use pads and use spring loaded headers on the AXE029 - fit the AXE029 with one spring-loaded header and one conventional so it can still be used on breadboard.
 

Technical

Technical Support
Staff member
We use the tag-connect (Microchip connector type) ourselves on some of our products
(e.g. see top centre of http://www.picaxe.com/Hardware/Add-on-Modules/PCB-scope/)

Although the pads are small and the PCB connector price is right (free!), the actual probe itself is surprisingly chunky and will actually take up more space than a 3 pin header with a servo style 3 pin cable..
 

WHITEKNUCKLES

New Member
For a number of years I have been using an extended version of the cable mentioned by hippy in post #3.

3.5mm socket to 3pin Molex pair to 3 probes.

3.5mm most convenient
3pin small footprint
3 probes no footprint

Socket/pins taken from female 0.1" headers make miniature plug/socket pairs and possibly the cheapest download.
 

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hippy

Technical Support
Staff member
Another thing to bear in mind is that anything which is not clip-on, has to be held against a board to be used, will soon become a pain in the proverbial if one needs to do any debugging with DEBUG or SERTXD commands.

Non clip-on are best suited to end of production line and occasional programming rather than development where it will often be download, test, edit, download again.
 

dmaxben

Member
Thanks for the responses everyone!

Im going to be "mass programming" production pieces.

Right now, with my current designs, I just have three through-hole pads, and I use the AXE027 with an 1/8" female stereo plug to 3-pin servo type plug adapter. I use a PCB header with slightly bent pins, so I can just stick it in the 3 holes on my board, and for the most part it stays in "good enough" with friction while I program the board.

It works, but Im just trying to come up with something a little more elegant and less fragile/touchy. The servo connector leads are 28awg (?) and ghetto-soldered to an 1/8" female headphone connector (for use with AXE027), so its a bit delicate. Also, it would be convenient to be able to also provide +5v power via my programming header...so I dont have to have two connectors hooked up (my power connector on the board, and the programming header)

Basically, Im just curious on what other people are doing for their in-circuit programming setups on mass-produced boards.

Lets discuss other alternative in-circuit-programming options that are compact as far as board real-estate, and dont require a soldered on through hole part (such as a servo connector). Edge-board connectors, etc???

And go!

Ben
 
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