Adapt board connector style

[Fred]

Hi,

This appears to be a regular question, so here is the answer in plain view.

When ordering your Tech Art XDP512 board, order it with the connector option FM for both sides.

The board looks like this when shipped with the FM option :









Admin.

[AbeFM]

The ribbon cable on the back is connecting to what? That's your I/O, to something like a jimstim?

[Fred]

Yeah, tomorrow I'll finish rigging up my test gear and put up some pictures.

My test rig actually consists of 5 boards :

Adapt MCU board
Power supply/spare strip board
50 pin idc header 1 strip board
50 pin idc header 2 strip board
JimStim

With 90 I/O channels the 12 LEDs on the JimStim just weren't enough :-)

Admin.

[AbeFM]

Indeed. Although a few of the LED's are two-way (multicolor) for those with tri-state bits in their eyes.

Why solder to the bottom of the JS when there are the wire blocks? No harm in it, but I'm curious. Really nice looking (noting the other, locked, thread as well).

Anyway, to take a stab at my own question, one header will be for I/O, the other, stacked, connector will be for talking to other boards? Looks pretty good.

Can you get a shroud for those pins on the top? Eeeks they look fragile. for PCI-104 connectors I've seen these:

... which just slide over the pins from the top. Most are designed to affix to prepared holes in the board, but even if you have to glue it on I bet it would help. Not exactly 'critical' but I've seen them prevent damage and ensure alignment in the past.

[Fred]

Why solder to the bottom of the JS when there are the wire blocks? No harm in it, but I'm curious. Really nice looking (noting the other, locked, thread as well).

Yeah, they are a nice piece of gear :-) The other thread has a comments thread of its own too you know :-)

The reason I've soldered ribbon straight to it is to keep those screw blocks free for potential future connection, and so I dont have to screw/unscrew wires. I'm going to put a 16 pin IDC connector on each proto board so that I can just plug the ribbon in.

Anyway, to take a stab at my own question, one header will be for I/O, the other, stacked, connector will be for talking to other boards? Looks pretty good.

Just having pins or plug or socket out the bottom would have been enough for both testing and for use in a car. However, the cost of the FM connector is the same as just one or the other, and it allows another small board (or large) to be hung off the top of the MCU board. It is also a direct connection with the scsi cables which are convenient for keeping things a bit physically separated and tidy. If you look at the "hardware wishlist" thread you will see in the first post how I intend that they will be stacked. I had initially thought I'd put the Input board on top and the Output board below, but Cam suggested that they should both be below. I liked his idea better than mine, but either is still possible if someone comes up with some good reasons to do or not do it a particular way.

Can you get a shroud for those pins on the top? Eeeks they look fragile.

Good idea! :-) You probably can get them, but not locally here, and they don't come with one. I have just had an idea though, and if it works I'll post a pic of it here when I'm done.

Not exactly 'critical' but I've seen them prevent damage and ensure alignment in the past.

It's not important if you install once and leave it there, but if you are pulling it out and pushing it in often, then it becomes important. I nearly stuffed my MS2 card in the same way. I was thinking the same thing with these, but the dual row IDC style are a lot easier to get straight than the MS2 card is.

Admin.

[AbeFM]

Yeah, they are a nice piece of gear The other thread has a comments thread of its own too you know

Are you kidding? A whole extra click?

The reason I've soldered ribbon straight to it is to keep those screw blocks free for potential future connection, and so I dont have to screw/unscrew wires.

Figured it was something like that, though I was trying to decide if it was a good way to go, i.e. you're still stuck with signals in parallel then. But it's not exactly terrible, either. Seen the JBperf breakout board? I just got one and it's great (though I used header connectors instead of screw blocks since all I ever do is hang an oscilloscope off it, so why put in a wire just to use it as a pin? Oh, and, you can make 0.200" pitch headers out of 0.100" if you dremel a slit in the tip of a pair of needle nose and then push out every other pin.

Just having pins or plug or socket out the bottom would have been enough for both testing and for use in a car. However, the cost of the FM connector is the same as just one or the other, and it allows another small board (or large) to be hung off the top of the MCU board.

Oh, I like that you can use a standard cable, ALWAYS a good thing. And of course, you don't have to use half the pins for grounds like a certain automotive DIY ecu just because the connector they are borrowing often does it that way. It's bad enough the few outputs on the CPU don't make it to the PCB, and it's worse the signals that make it there can't make it out of the box, especially when there are 18 redundant pins.

Good idea! You probably can get them, but not locally here, and they don't come with one. I have just had an idea though, and if it works I'll post a pic of it here when I'm done.

Just to give you some ideas....

It's not important if you install once and leave it there, but if you are pulling it out and pushing it in often, then it becomes important. I nearly stuffed my MS2 card in the same way. I was thinking the same thing with these, but the dual row IDC style are a lot easier to get straight than the MS2 card is.

Ha! That's what you think! The reason they tend to use the shrouds is not for alignment so much, all that takes is a bit of care on assembly. They do it for shock and vibration resistance, the two plastic bits end up being fixed to the board directly so there's less shear force on the pins. So they say.

[Fred]

Ha! That's what you think! :-P The reason they tend to use the shrouds is not for alignment so much, all that takes is a bit of care on assembly. They do it for shock and vibration resistance, the two plastic bits end up being fixed to the board directly so there's less shear force on the pins. So they say.

Interesting. That is a good idea, and if they can be got, we should provision holes for them in the boards when we design them. My idea (that you gave me) was to use a 40pin idc socket and slice it into three parts, slide it over the header pins and just use it to stop me bending the pins in a rush. I bought some super glue today, so, if i like them, I can glue them down.

"Maplins" had no stock of the 40 way ones today, so I'll have to wait for that now, but it's low on the list anyway.

Thanks for your input!

Admin.