gipetto wrote: 28 Nov 2019, 14:21
I don't know much about hall effect but I bought two of these alps em11b and according to the datasheet they are 5v friendly, so easy to interface with. you could remove the sensors from them.
https://www.aliexpress.com/item/32749448630.html
DMA wrote: 28 Nov 2019, 06:50
so.. sensors themselves don't contribute anything to the key feel, I guess. See if you can put a SOT-23 into the switch. Or a SIP-3 - might be easier. There are hall effect sensors in those form-factors. Some of them even have a disable pin which will allow you to build a matrix out of them.
DMA wrote: 28 Nov 2019, 06:50
so.. sensors themselves don't contribute anything to the key feel, I guess. See if you can put a SOT-23 into the switch. Or a SIP-3 - might be easier. There are hall effect sensors in those form-factors. Some of them even have a disable pin which will allow you to build a matrix out of them.
Interesting. I had just presumed that this type of sensor was special to Micro Switch switches and never really thought about looking outside of that world. Glad to know there are some other options out there. I may pick some of these things up to play around with or at least to have on hand.
Slom actually hooked me up with links to a couple of ebay listings selling loose switches. I had looked there in the past plenty of times but could only find single switches for $20 each. Funny how that works. According to Slom's note and the model numbers on the switches, one batch of them should be the "sink hold" variety which is great news. I guess I'll find out soon enough when I test them out.
XMIT wrote: 28 Nov 2019, 16:39
Just catching up here. You're really lucky, to have had three rows of "hold" type switches up top. I didn't have that option with mine.
I still need to finish converting mine. There are two options for how I'll proceed:
1. Strobe power to the "pulse" switches to turn them into "hold" switches, effectively.
2. Replace the sensors (create new Hall daughterboards).
Either of these may require some PCB work, possibly up to an entire PCB.
Glad you got this working!
Yeah I had explored trying alternative methods to get the pulse switches to hold but a lot of the methods suggested by folks were a bit over my head, and/or like you said, require a new PCB.
Which would be a shame because the PCBs on these Micro Switch boards are really neat. The one in this board is so cool looking, I'm almost sad that it's hidden inside the case.
If you do end up printing a new PCB for yours, you could frame the old one up and make some awesome wall art!
The tip on the switches was enough motivation for me to give everything a good scrub down and finally put it back together.
One challenge I'm going to have is figuring out where to place the microcontroller. Most of the components on this board were all at the very front of the board, where there's not a ton of space (especially because the PCB is lifted up by risers so there's a lot of room in "the basement"). There's also a ton of rows and columns necessitating a lot of wires which translate into bulk inside the case. It'd be a breeze if everything was located toward the back where there's plenty of room.
I'll probably see first if it will squeeze into the remaining space in the front. If that doesn't work, I'll end up running longer wires so I can seat it all comfortably in the back. She'll be pretty on the outside but likely to be a mess inside
Almost to the finish line!
I can't stress enough how much I appreciate all the advice I've gotten in this thread. Really, huge thanks to everyone who helped me out along the way.
