Proton C Conversion
Since the Proton C is a drop-in replacement for a Pro Micro we've made it easy to use. This page documents a handy automated process for converting keyboards, as well as documenting the manual process if you'd like to make use of Proton C features that aren't available on Pro Micros.

Automatic Conversion

If a board currently supported in QMK uses a Pro Micro (or compatible board) and you want to use the Proton C, you can generate the firmware by appending CONVERT_TO_PROTON_C=yes (or CTPC=yes) to your make argument, like this:
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make 40percentclub/mf68:default CTPC=yes
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You can add the same argument to your keymap's rules.mk, which will accomplish the same thing.
This exposes the CONVERT_TO_PROTON_C flag that you can use in your code with #ifdefs, like this:
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#ifdef CONVERT_TO_PROTON_C
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// Proton C code
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#else
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// Pro Micro code
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#endif
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If you get errors about PORTB/DDRB, etc not being defined, so you'll need to convert the keyboard's code to use the GPIO Controls that will work for both ARM and AVR. This shouldn't affect the AVR builds at all.
The Proton C only has one on-board LED (C13), and by default, the TXLED (D5) is mapped to it. If you want the RXLED (B0) mapped to it instead, add this like to your config.h:
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#define CONVERT_TO_PROTON_C_RXLED
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Feature Conversion

These are defaults based on what has been implemented for ARM boards.
Feature
Notes
Audio
Enabled
Disabled
Backlight
Forces task driven PWM until ARM can provide automatic configuration
USB Host (e.g. USB-USB converter)
Not supported (USB host code is AVR specific and is not currently supported on ARM)
Partial - heavily dependent on enabled features

Manual Conversion

To use the Proton C natively, without having to specify CTPC=yes, you need to change the MCU line in rules.mk:
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MCU = STM32F303
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BOARD = QMK_PROTON_C
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Remove these variables if they exist:
  • BOOTLOADER
  • EXTRA_FLAGS
Finally convert all pin assignments in config.h to the stm32 equivalents.
Pro Micro Left
Proton C Left
Proton C Right
Pro Micro Right
D3
A9
5v
RAW (5v)
D2
A10
GND
GND
GND
GND
FLASH
RESET
GND
GND
3.3v
VCC 1
D1
B7
A2
F4
D0
B6
A1
F5
D4
B5
A0
F6
C6
B4
B8
F7
D7
B3
B13
B1
E6
B2
B14
B3
B4
B1
B15
B2
B5
B0
B9
B6
B0 (RX LED)
C13 2
C13 2
D5 (TX LED)
You can also make use of several new pins on the extended portion of the Proton C:
Left
Right
A43
B10
A54
B11
A6
B12
A7
A145 (SWCLK)
A8
A135 (SWDIO)
A15
RESET6
Notes:
  1. 1.
    On a Pro Micro VCC can be 3.3v or 5v.
  2. 2.
    A Proton C only has one onboard LED, not two like a Pro Micro. The Pro Micro has an RX LED on D5 and a TX LED on B0.
  3. 3.
    A4 is shared with the speaker.
  4. 4.
    A5 is shared with the speaker.
  5. 5.
    A13 and A14 are used for hardware debugging (SWD). You can also use them for GPIO, but should use them last.
  6. 6.
    Short RESET to 3.3v (pull high) to reboot the MCU. This does not enter bootloader mode like a Pro Micro, it only resets the MCU.
Last modified 9mo ago