Non-permanent parallel bit connection

Hi,

I’m new to using rabbit technology and electronics, and I’m planning on interfacing a robotic arm with my 4000-series development kit’s prototyping board; I would prefer not to solder the connections onto this board as I do not want them to be quite so permanent, and I have little soldering experience so all the more reason to avoid this if possible.

Does anyone have any suggestions for how to make a non-permanent connection, but secure connection? I was thinking obtaining metal pins of the correct diameter to be a fairly tight fit in the holes in the prototyping board, and soldering the wires onto these pins instead of directly to the board. Any better ideas?

Thanks in advance.

Giftiger Wunsch

I’m not sure you’re going to be bale to make a reliable connection to the holes in the board without soldering. How about soldering a header (e.g., http://ecommas.tycoelectronics.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Customer+Drawing87215JpdfEnglishENG_CD_87215_J.pdf) onto the board? Then you would have pins that you could make reliable non-permanent connections to. Either with a matching receptacle or using individual receptacle contacts…

I figured that might be a problem. Thanks for the idea though, that would do pretty nicely. Really my main problem is I have a nice shiny (well, not so much) prototyping board and I don’t want to do anything to it which I’ll later regret. But at some point it needs to stop being a shiny thing which doesn’t do much :stuck_out_tongue:

I also have a second unrelated question… I’m fairly confident that it is possible but always good to check with someone who has more experience since I’ve done very little with my processor / prototyping board yet: in another post you told me how an LED may be connected between the 3.3V supply port and one of the parallel port bits to turn it on with a logic low, would it also function correctly to connect a device between say PA0 and PA1, so that the voltage and direction across the device could be controlled by the two ports?

Thanks.

Yes, that should work just fine. Just make sure that the current requirements of the device you’re driving are met. It’s common for digital outputs to be able to sink more current than they can source, though the Rabbit specs (at least on the 4000 and 5000 processors) do not indicate any asymmetry (looking at I[DRIVE] specs) - looks like you can assume at least 8ma for any output.

Thanks, I should have that one covered. I’ve been trying to figure out how best to use the prototyping board to drive five motors, and so far it’s gone from BJTs to MOS-FETs back to BJTs to MOS-FET driver ICs. I’ll eventually get that sorted out though.

Thanks for the confirmation, and for the header suggestion.

Giftiger,

Have you considered using a solderless breadboard?

Rather than trying to work within the limited space on the prototyping board, solder a 50-pin header (as suggested earlier) to the proto-board and then make yourself a cable (cannibalize an old 50-pin SCSI cable and solder the individual wires on one end to DIP-headers) which can be plugged into the solderless breadboard.

Alternatively, you could use wire-wrap sockets, although wire-wrapping is a real pain.

Indeed, I am mainly going to be using a breadboard for temporary circuits; I have a couple of them which I have already used to prototype various circuits. The main issues was making a connection to the board which could easily be adapted, rather than making temporary circuits and then connecting them to the board.

For more permanent solutions, I’ll be using tripad board or stripboard until I can get myself some etchiong equipment to make actual PCBs.

The header idea is a good one though, I’ll most likely do that once I find suitable items.