Raspbery Pi Zero GPIO keyboard driver

So I am building a project that uses a Raspberry Pi Zero. I have the files Ben Heck used to use the GPIO for the keyboard matrix, however, I am need a different key layout. More importantly, a layered key layout sine it's a 40% design, similar to a Planck keyboard. Unfortunately, I don't know how to code and cannot information on how to do what I need to do. Where should I go to find information on implementing a layered keyboard matrix through the GPIO using this software?

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0 amgalbu over 4 years ago

Hello Jack
in general if you have a keyboard matrix with "r" rows and "c" columns, you have to configure "r" GPIOs as outputs and "c" GPIOs as inputs
Then, in your code you have to create a loop where
1. set the i-th output to 1 and all the other outputs to 0 (i ranges from 1 to "r")
2. read all the "c" inputs. If an j-th input is read as 1, the key at position (i, j) has been pressed

Bye and good luck for your project!
Ambrogio
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0 the_antithesis over 4 years ago in reply to amgalbu

Okay, but how to I make a layered layout. I'm working with only 48 keys and need to use keyboard layers. I found this software here, which should do what I need but I'm unsure of the syntax to add a second keyboard layer using the FN_1 key to switch layers and to set it as a toggle. This is the code I need to alter:

https://github.com/thebenheckshow/244-tbhs-raspberry-pi-zero-portable/tree/master/Code/Keypad

The layout is in 244-tbhs-raspberry-pi-zero-portable/Code/Keypad/Build/source/Keypad_Driver_V13.c
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0 the_antithesis over 4 years ago in reply to amgalbu

Okay, but how to I make a layered layout. I'm working with only 48 keys and need to use keyboard layers. I found this software here, which should do what I need but I'm unsure of the syntax to add a second keyboard layer using the FN_1 key to switch layers and to set it as a toggle. This is the code I need to alter:

https://github.com/thebenheckshow/244-tbhs-raspberry-pi-zero-portable/tree/master/Code/Keypad

The layout is in 244-tbhs-raspberry-pi-zero-portable/Code/Keypad/Build/source/Keypad_Driver_V13.c
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0 amgalbu over 4 years ago in reply to the_antithesis

Sorry Jack
You have to handle keyboard layers in software
So, basically
1. add an integer variable (let's call this variable fn_status) to Keypad_Driver_V13.c
2. copy&paste array "abc", rename it abc_1 and fill it with the proper values
3. when FN_1 is pressed, toggle the value of fn_status (fn_status != fn_status)
4. in the main() function, replace
   if ( returnKeyPress != -1 ){
   send_event(fd, EV_KEY, abc[returnKeyPress], 1);
with something like
   if ( returnKeyPress != -1 ){
   send_event(fd, EV_KEY, (fn_status)? abc_1[returnKeyPress] : abc[returnKeyPress], 1);

Obviously this is just to give you an idea. Many other approaches are possible

Bye!
Ambrogio
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if ( returnKeyPress != -1 ){
	send_event(fd, EV_KEY, abc[returnKeyPress], 1);

if ( returnKeyPress != -1 ){
	send_event(fd, EV_KEY, (fn_status)? abc_1[returnKeyPress] : abc[returnKeyPress], 1);