QMK firmware

README.md

@@ -29,16 +29,21 @@ Be advised that right now the underglow only works on the XIAO nRF52840 board, a
 | Board                 | Chip     | USB Wired          | Bluetooth Wireless | RGB Underglow      | Comments                                                     |
 | --------------------- | -------- | ------------------ | ------------------ | ------------------ | ------------------------------------------------------------ |
 | XIAO                  | SAMD21   | :white_check_mark: | :x:                | :x:                | Should work but untested                                     |
-| Adafruit Qt PY        | SAMD21   | :white_check_mark: | :x:                | :x:                | Should work but untested                                     |
 | XIAO BLE              | nRF52840 | :white_check_mark: | :white_check_mark: | :white_check_mark: |                                                              |
 | XIAO RP2040           | RP2040   | :white_check_mark: | :x:                | :x: for now        | Underglow [maybe someday](https://github.com/zmkfirmware/zmk/issues/1085) |
-| Adafruit Qt PY RP2040 | RP2040   | :white_check_mark: | :x:                | :x: for now        | Should work but untested                                     |
 
 ### QMK
 
-I have not written QMK firmware yet, but maybe I will for the RP2040.
+Copy the contents of `firmware/qmk/keyboards/re_gret` into `[your_qmk_firmware]/keyboards/re_gret`, since I have not put the Re-gret firmware into the official QMK repo.
+
+Only the XIAO RP2040 is supported. The Adafruit QT Py RP2040 might possibly work but I don't think the reset button will function.
+
+| Board                 | Chip     | USB Wired          | RGB Underglow      | Comments                                                     |
+| --------------------- | -------- | ------------------ | ------------------ | ------------------------------------------------------------ |
+| XIAO RP2040           | RP2040   | :white_check_mark: | :white_check_mark: |  |
 
 ## Related
 
 * I cribbed the Xiao footprint, pogo pin idea, and battery from the [revxlp](https://gitlab.com/lpgalaxy/revxlp)
+* I based the QMK shift register matrix code on [Sadek's](https://github.com/sadekbaroudi/qmk_firmware)
 * My original 36 key [Egret](https://github.com/rschenk/egret) was the starting point

firmware/qmk/keyboards/re_gret/config.h

@@ -0,0 +1,31 @@
+// Copyright 2024 Ryan Schenk (@rschenk)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#define MATRIX_COLS 5
+#define MATRIX_ROWS 8
+
+#define SPI_SCK_PIN GP2
+#define SPI_MOSI_PIN GP3
+#define SPI_MISO_PIN NO_PIN
+
+#define SHIFTREG_MATRIX_ROW_CS GP4
+#define SHIFTREG_DIVISOR 8
+#define SHIFTREG_COLS 5
+#define SHIFTREG_ROWS 8
+
+#define MATRIX_COL_PINS { GP27, GP28, GP29, GP6, GP7 }
+// Row Number 0 1 2 3 4 5 6 7       
+// SHR Pin Q: H G F E A B C D
+#define SHIFTREG_ROW_PINS { 0x80, 0x40, 0x20, 0x10, 0x01, 0x02, 0x04, 0x08 }
+
+#define WS2812_DI_PIN GP26
+#define RGBLIGHT_LED_COUNT 11
+
+#ifdef RGBLIGHT_ENABLE
+  #define RGBLIGHT_EFFECT_RAINBOW_SWIRL   // enable rainbow swirl
+  #define RGBLIGHT_SLEEP                  // turn off LEDs when host sleeps
+  #define RGBLIGHT_LAYERS                 // per-layer LED effects
+  #define RGBLIGHT_DEFAULT_MODE RGBLIGHT_MODE_RAINBOW_SWIRL
+#endif

firmware/qmk/keyboards/re_gret/halconf.h

@@ -0,0 +1,10 @@
+// Copyright 2024 Ryan Schenk (@rschenk)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#define HAL_USE_SPI TRUE
+#define SPI_USE_WAIT TRUE
+#define SPI_SELECT_MODE SPI_SELECT_MODE_PAD
+
+#include_next <halconf.h>

firmware/qmk/keyboards/re_gret/keyboard.json

@@ -0,0 +1,63 @@
+{
+    "manufacturer": "Ryan Schenk",
+    "keyboard_name": "re_gret",
+    "maintainer": "rschenk",
+    "bootloader": "rp2040",
+    "diode_direction": "ROW2COL",
+    "features": {
+        "bootmagic": true,
+        "command": false,
+        "console": false,
+        "extrakey": true,
+        "mousekey": true,
+        "nkro": true
+    },
+    "processor": "RP2040",
+    "url": "https://github.com/rschenk/re-gret",
+    "usb": {
+        "device_version": "1.0.0",
+        "pid": "0xE9E8",
+        "vid": "0xFEED"
+    },
+    "community_layouts": ["split_3x5_2"],
+    "layouts": {
+        "LAYOUT_split_3x5_2": {
+            "layout": [
+                {"matrix": [0, 0], "x": 0, "y": 0.25},
+                {"matrix": [0, 1], "x": 1, "y": 0.125},
+                {"matrix": [0, 2], "x": 2, "y": 0},
+                {"matrix": [0, 3], "x": 3, "y": 0.125},
+                {"matrix": [0, 4], "x": 4, "y": 0.25},
+                {"matrix": [4, 4], "x": 7, "y": 0.25},
+                {"matrix": [4, 3], "x": 8, "y": 0.125},
+                {"matrix": [4, 2], "x": 9, "y": 0},
+                {"matrix": [4, 1], "x": 10, "y": 0.125},
+                {"matrix": [4, 0], "x": 11, "y": 0.25},
+                {"matrix": [1, 0], "x": 0, "y": 1.25},
+                {"matrix": [1, 1], "x": 1, "y": 1.125},
+                {"matrix": [1, 2], "x": 2, "y": 1},
+                {"matrix": [1, 3], "x": 3, "y": 1.125},
+                {"matrix": [1, 4], "x": 4, "y": 1.25},
+                {"matrix": [5, 4], "x": 7, "y": 1.25},
+                {"matrix": [5, 3], "x": 8, "y": 1.125},
+                {"matrix": [5, 2], "x": 9, "y": 1},
+                {"matrix": [5, 1], "x": 10, "y": 1.125},
+                {"matrix": [5, 0], "x": 11, "y": 1.25},
+                {"matrix": [2, 0], "x": 0, "y": 2.25},
+                {"matrix": [2, 1], "x": 1, "y": 2.125},
+                {"matrix": [2, 2], "x": 2, "y": 2},
+                {"matrix": [2, 3], "x": 3, "y": 2.125},
+                {"matrix": [2, 4], "x": 4, "y": 2.25},
+                {"matrix": [6, 4], "x": 7, "y": 2.25},
+                {"matrix": [6, 3], "x": 8, "y": 2.125},
+                {"matrix": [6, 2], "x": 9, "y": 2},
+                {"matrix": [6, 1], "x": 10, "y": 2.125},
+                {"matrix": [6, 0], "x": 11, "y": 2.25},
+                {"matrix": [3, 3], "x": 3.5, "y": 3.25},
+                {"matrix": [3, 4], "x": 4.5, "y": 3.5},
+                {"matrix": [7, 4], "x": 6.5, "y": 3.5},
+                {"matrix": [7, 3], "x": 7.5, "y": 3.25}
+            ]
+        }
+    }
+}

firmware/qmk/keyboards/re_gret/keymaps/default/keymap.c

@@ -0,0 +1,26 @@
+// Copyright 2023 QMK
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+     /*
+      * ┌───┬───┬───┬───┬───┐       ┌───┬───┬───┬───┬───┐
+      * │ Q │ W │ E │ R │ T │       │ Y │ U │ I │ O │ P │
+      * ├───┼───┼───┼───┼───┤       ├───┼───┼───┼───┼───┤
+      * │ A │ S │ D │ F │ G │       │ H │ J │ K │ L │ ; │
+      * ├───┼───┼───┼───┼───┤       ├───┼───┼───┼───┼───┤
+      * │ Z │ X │ C │ V │ B │       │ N │ M │ , │ . │ / │
+      * └───┴───┴───┴───┴───┘       └───┴───┴───┴───┴───┘
+      *               ┌───┐           ┌───┐
+      *               │Bsp├───┐   ┌───┤Ent│
+      *               └───┤Tab│   │Spc├───┘
+      *                   └───┘   └───┘
+      */
+    [0] = LAYOUT_split_3x5_2(
+        KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,                               KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,
+        KC_A,    KC_S,    KC_D,    KC_F,    KC_G,                               KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN,
+        KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,                               KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH,
+                                            KC_BSPC, KC_TAB,           KC_SPC,  KC_ENT
+    )
+};

firmware/qmk/keyboards/re_gret/matrix.c

@@ -0,0 +1,153 @@
+// Copyright 2024 Ryan Schenk (@rschenk)
+// Copyright 2022 @sadekbaroudi (Sadek Baroudi)
+// SPDX-License-Identifier: GPL-3.0-or-later
+#include "quantum.h"
+#include "spi_master.h"
+#include <string.h> /* memset */
+#include <unistd.h> /* close */
+#include "quantum.h"
+#include "matrix.h"
+#ifdef FP_SR595_MATRIX_DEBUG
+#include <time.h>
+#include <stdlib.h>
+#define FP_SR595_MATRIX_DEBUG_RATIO 10000
+#endif
+
+#if (!defined(SHIFTREG_MATRIX_ROW_CS))
+#    error Missing shift register I/O pin definitions
+#endif
+
+int matrixArraySize = MATRIX_ROWS * sizeof(matrix_row_t);
+matrix_row_t oldMatrix[MATRIX_ROWS];
+
+#define SHIFTREG_OUTPUT_BITS 8
+pin_t colPinsSR[MATRIX_COLS] = MATRIX_COL_PINS;
+uint8_t rowPinCodesSR[SHIFTREG_ROWS] = SHIFTREG_ROW_PINS;
+
+// semaphore to make sure SPI doesn't get called multiple times
+static bool shiftRegisterSPILocked = false;
+
+void semaphore_lock(bool value) {
+    shiftRegisterSPILocked = value;
+}
+
+bool semaphore_is_locked(void) {
+    return shiftRegisterSPILocked;
+}
+
+void sr_74hc595_spi_stop(void) {
+    spi_stop();
+    semaphore_lock(false);
+}
+
+bool sr_74hc595_spi_start(void) {
+    if (!spi_start(SHIFTREG_MATRIX_ROW_CS, false, 0, SHIFTREG_DIVISOR)) {
+        dprintf("74hc595 matrix: failed to start spi\n");
+        sr_74hc595_spi_stop();
+        return false;
+    }
+
+    semaphore_lock(true);
+    wait_us(1); // not sure if I need this
+    return true;
+}
+
+bool sr_74hc595_spi_send_byte(uint8_t data) {
+    sr_74hc595_spi_start();
+    gpio_write_pin_low(SHIFTREG_MATRIX_ROW_CS);
+    matrix_io_delay();
+    spi_write(data);
+    matrix_io_delay();
+    gpio_write_pin_high(SHIFTREG_MATRIX_ROW_CS);
+    sr_74hc595_spi_stop();
+    return true;
+}
+
+/**
+ * Set the entire shift register to be full of inactive bits
+ */
+void clearRows(void) {
+    uint8_t value = 0b00000000;
+    sr_74hc595_spi_send_byte(value);
+}
+
+void setRow(int rowNumber, bool test_run) {
+    uint8_t rowShiftByte = rowPinCodesSR[rowNumber];
+    if(test_run) {
+        dprintf("byte sent: %d\n", rowShiftByte);
+    }
+    sr_74hc595_spi_send_byte(rowShiftByte);
+}
+
+/*
+ * Override QMK matrix initialization
+ */
+void matrix_init_custom(void) {
+    wait_ms(300);
+    spi_init();
+
+    // Set up initial states for all the column pins
+    for(int c = 0; c < SHIFTREG_COLS; c++) {
+        // Note: This needs to use the internal pull down resistors, and atmegas
+        // do *not* support that
+        gpio_set_pin_input_low(colPinsSR[c]);
+    }
+
+    // Set the CS to low by default, and specify as an output pin
+    gpio_write_pin_high(SHIFTREG_MATRIX_ROW_CS); // should be high when using SPI?
+    gpio_set_pin_output(SHIFTREG_MATRIX_ROW_CS);
+
+    // Since it's the init, deactivate all the columns. We'll activate once we
+    // get to the matrix scan
+    clearRows();
+}
+
+/*
+ * Override QMK matrix scan
+ */
+bool matrix_scan_custom(matrix_row_t current_matrix[]) {
+    // respect the semaphore
+    if (semaphore_is_locked()) {
+        return false;
+    }
+
+    bool matrix_has_changed = false;
+
+    // reset the current matrix, as we'll be updating and comparing to the old matrix
+    memset(current_matrix, 0, matrixArraySize);
+
+#ifdef FP_SR595_MATRIX_DEBUG
+    bool debug_output = ((rand() % FP_SR595_MATRIX_DEBUG_RATIO) == 1);
+#else
+    bool debug_output = false;
+#endif
+
+    // Loop through the rows, activating one at a time, and read the columns,
+    // and place in the new current_matrix
+    for (int r = 0; r < SHIFTREG_ROWS; r++) {
+        if (debug_output) {
+            dprintf("row iteration: %d\n", r);
+        }
+        setRow(r, debug_output);
+        matrix_io_delay();
+
+        for (int c = 0; c < SHIFTREG_COLS; c++) {
+            current_matrix[r] |= ((gpio_read_pin(colPinsSR[c]) ? 1 : 0) << c);
+        }
+    }
+
+    matrix_has_changed = memcmp(current_matrix, oldMatrix, matrixArraySize) != 0;
+    memcpy(oldMatrix, current_matrix, matrixArraySize);
+
+#ifdef FP_SR595_MATRIX_DEBUG
+    if (matrix_has_changed) {
+        matrix_print();
+    }
+#endif
+
+    // Deactivate all the columns for the next run.
+    clearRows();
+    matrix_io_delay();
+
+    return matrix_has_changed;
+}

firmware/qmk/keyboards/re_gret/mcuconf.h

@@ -0,0 +1,9 @@
+// Copyright 2024 Ryan Schenk (@rschenk)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include_next <mcuconf.h>
+
+#undef RP_SPI_USE_SPI0
+#define RP_SPI_USE_SPI0 TRUE

firmware/qmk/keyboards/re_gret/readme.md

@@ -0,0 +1,27 @@
+# Re-gret
+
+![re_gret](https://github.com/rschenk/re-gret/blob/main/images/IMG_0812.jpeg?raw=true)
+
+A 34-key keyboard powered by a Seeed XIAO RP2040, with hot-swappable ChocV1 switches.
+
+* Keyboard Maintainer: [Ryan Schenk](https://github.com/rschenk)
+* Hardware Supported: Re-gret PCB with Seeed XIAO RP2040 controller
+* Hardware Availability: Gerbers are available in the [Re-gret repo](https://github.com/rschenk/re-gret) and the controller is available from [Seeed Studio](https://www.seeedstudio.com/XIAO-RP2040-v1-0-p-5026.html)
+
+Make example for this keyboard (after setting up your build environment):
+
+    make re_gret:default
+
+Flashing example for this keyboard:
+
+    make re_gret:default:flash
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).
+
+## Bootloader
+
+Enter the bootloader in 3 ways:
+
+* **Bootmagic reset**: Hold down the top-left key ("Q" on qwerty) and plug in the keyboard
+* **Physical reset button**: Double click the reset button
+* **Keycode in layout**: Press the key mapped to `QK_BOOT` if it is available

firmware/qmk/keyboards/re_gret/rules.mk

@@ -0,0 +1,6 @@
+SRC += matrix.c
+
+SPI_DRIVER_REQUIRED = yes
+CUSTOM_MATRIX = lite
+RGBLIGHT_ENABLE = yes
+WS2812_DRIVER = vendor