geekhack
geekhack Projects => Making Stuff Together! => Topic started by: Spiwocoal on Mon, 31 August 2020, 19:36:51
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Hi, I am working in a custom keyboard PCB that would be modular and you could attach different modules to a main board like a Numpad, a Macropad, etc… The PCB is mostly done, but for some time I’ve been struggling with the physical connection between the “modules”.
Awhile ago, I found out that the Ultimate Hacking Keyboard (http://ultimatehackingkeyboard.com/) has a way of joining both halves and connecting their modules that’s very similar to what I had thought to use, and as the electrical design files are open-source, I gave a look to see if I could adapt it to my needs.
The problem is, there were some things I didn’t quite understand how they worked. I know those connectors are on a separate PCB, but I couldn’t find how they were connecting to the main boards, and as I don’t have a UHK nor $275 to spare, I can’t give it a look to see how it works.
So I thought on asking you guys to see if someone has an idea on how it works or has a UHK and is willing to disassemble it and take some photos for me. If you could do any of those things it would be really great! But I won't force anybody of course.
Anyways, as a side note, I hope y’all have or had a great day!
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- whether wired or put together with no additional cable the two halves of the matrix talk to each other over i2c (trrs, 4 pins)
- they are using an arm micro controller with multiple UARTs which is how they are adding the additional functionality with the modules
- there is also an SPI interface, which doesn't look like it's used.
- there's more "guts" in the right half then the left half, look at the PDFs of the electronics/right-main (also why the usb connector is on the right half, it's the master half)
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Just from what I've seen on some other split boards the pogo pins are just a USB connection.
Each module is it's own "keyboard" and the pins are just a pass through for the USB connection.
In other words, the main system contains a 3 or 4 port USB hub. Connected to port one of the hub is the main keyboard it's housed in, the second port goes to the other keyboard half, the third port goes to the pogo pins. In the second half of the keyboard is a similar setup, a small USB hub, port 1 has the keyboard and the second port goes to pogo pins.
It sounds silly but when you can get these single chip USB hubs and cheap processors chips for only a couple bucks it makes total sense.
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Just from what I've seen on some other split boards the pogo pins are just a USB connection.
Each module is it's own "keyboard" and the pins are just a pass through for the USB connection.
In other words, the main system contains a 3 or 4 port USB hub. Connected to port one of the hub is the main keyboard it's housed in, the second port goes to the other keyboard half, the third port goes to the pogo pins. In the second half of the keyboard is a similar setup, a small USB hub, port 1 has the keyboard and the second port goes to pogo pins.
It sounds silly but when you can get these single chip USB hubs and cheap processors chips for only a couple bucks it makes total sense.
that might work for the additional modules but it wouldn't work for the main keyboard. modifiers and Fn do not pass through to a 2nd usb keyboard (they have to be on the same USB device, if connected to a USB hub they would have different addresses)
the two halves are definitely connected via i2c (not serial, not usb)
- in the 4P4C (top curly cable) SDA, SDL, VCC & GND
- in the "pogo pin connector SDA, SDL, VCC & GND
the extra components around the connector are knocking down the 5v to 3.3v
- the modules connect via the 5 pin "pogo" connector and are all the same setup SDA, SDL, VCC & GND
so each of these modules have their own controller inside them (part of the reason they are $60/each)
[attach=1]
[attach=2]
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Ahh, good point about the function layers.
Bummer it's so expensive to do it that way.
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- whether wired or put together with no additional cable the two halves of the matrix talk to each other over i2c (trrs, 4 pins)
- they are using an arm micro controller with multiple UARTs which is how they are adding the additional functionality with the modules
- there is also an SPI interface, which doesn't look like it's used.
- there's more "guts" in the right half then the left half, look at the PDFs of the electronics/right-main (also why the usb connector is on the right half, it's the master half)
Just from what I've seen on some other split boards the pogo pins are just a USB connection.
Each module is it's own "keyboard" and the pins are just a pass through for the USB connection.
In other words, the main system contains a 3 or 4 port USB hub. Connected to port one of the hub is the main keyboard it's housed in, the second port goes to the other keyboard half, the third port goes to the pogo pins. In the second half of the keyboard is a similar setup, a small USB hub, port 1 has the keyboard and the second port goes to pogo pins.
It sounds silly but when you can get these single chip USB hubs and cheap processors chips for only a couple bucks it makes total sense.
that might work for the additional modules but it wouldn't work for the main keyboard. modifiers and Fn do not pass through to a 2nd usb keyboard (they have to be on the same USB device, if connected to a USB hub they would have different addresses)
the two halves are definitely connected via i2c (not serial, not usb)
- in the 4P4C (top curly cable) SDA, SDL, VCC & GND
- in the "pogo pin connector SDA, SDL, VCC & GND
the extra components around the connector are knocking down the 5v to 3.3v
- the modules connect via the 5 pin "pogo" connector and are all the same setup SDA, SDL, VCC & GND
so each of these modules have their own controller inside them (part of the reason they are $60/each)
Thank you to all of you guys, but I seemingly forgot to specify that what I need help with is the physical connector, the communication protocol I had already figured how it worked, sorry for the inconvenience... :/
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the pogo connector is just spring loaded pins on one side and solid contacts on the other being held together with the two sets of tight fitting sleves & pins above the connector. there might be magnets as well i don't remember.
watch chryos
as far as what that connector actually is called? who knows. but you could probably find something similar.
magnetic usb is 5 conductor (as long as it's a data cable and not just a charge cable)
similar connectors were used in printers/copiers where the drums or toner cartridges connect....
basically just a pressure contact connector
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did a quick search..."spring loaded connector mouser"
1st result. https://www.mouser.com/new/mill-max/mill-max-spring-loaded-headers/
spring loaded millmax nicknamed "pogo" connectors
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did a quick search..."spring loaded connector mouser"
1st result. https://www.mouser.com/new/mill-max/mill-max-spring-loaded-headers/
spring loaded millmax nicknamed "pogo" connectors
Thank you so much!
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keep us posted as to what you're working on.... curious.