Soldering is fine by me... As long as it works... I don't think loosing the original keyboard is a big problem since the whole point was to replace an already non-functioning keyboard.
Frans Andrew Gale wrote: > Spurred on by the recent interest in my PC keyboard interface, > I've more-or-less finished a PCB for it this weekend - hopefully > I will get the chance to make it next weekend. I could do with > some advice first, however. > > The interface I've got is designed to be internal - that is > it needs soldering inside the SAM. The reason I went for this > option is that it only needs about half the number of chips > as an external version, a smaller PCB, and it seemed a nice > and neat solution - it doesn't require a precious spare > expansion slot. > > However, it means that a bit of soldering is needed - there > is one 9-way ribbon cable and one 8-way ribbon cable that need > soldering to the SAM's motherboard keyboard connectors. On mine > I have soldered the wires onto the pins on the underside of the > motherboard, which was a bit fiddly but works fine - it also > means that I can still plug in and use the SAM keyboard. The > alternative is to desolder the black connectors into which the > membrane pushes and solder the ribbon cables directly into the holes, > but now the original SAM keyboard will be inoperable. The third > possibility (but no promises on this one) is that I may be able > to get some thin pcb which I can solder onto the ribbon cable so > that all you have to do is push it into the existing keyboard > connectors, much like you do with the membrane. Again, the existing > SAM keyboard will be unusable unless I can get hold of some of those > 8 and 9-way keyboard connectors to make through connections. There > will still be four wires to solder onto the mainboard, however (+5v, > 0v, NMI and RESET --- ctrl+alt+break will give a de-bounced NMI and > ctrl+alt+del will give a reset). > > Basically, then, what I want to know is: is this all too much hassle? > I can do the external interface if it is, but you'll have to wait > a while for it. > > As for posting the schematic, I'm afraid I can't do that just yet - not > least because I don't actually have one! The thing has sort of evolved > on stripboard. Also, the circuit isn't fixed - basically I have > a number of things I can move around in order to simplify the pcb, > so I can't really post a schematic until after I've finished the > pcb design. (The software for the microcontroller needs modifying > according to the final pcb layout). > > I hope to have more news soon - please let me know how much hassle you > would be prepared to go to to install this thing - do you mind losing > the use of your [part-dead?] SAM keyboard? > > Thanks, > > Andy >
