Add Word Per Minute calculation feature (#8054)

* Add Word Per Minute calculation feature

* Fix copyright info

* Remove header from quantum.c, setup overloadable keycode inclusion for WPM, update docs

* Simplify logic for keycode filtering

* Adding link from summary to wpm_feature info

* Update docs/feature_wpm.md

Typo in function prototype example in docs

Co-Authored-By: James Young <18669334+noroadsleft@users.noreply.github.com>

* Add WPM transport via i2c

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

6 files changed, 142 insertions, 0 deletions

diff --git a/common_features.mk b/common_features.mk
index 471d4456a5..0488b64edc 100644
--- a/common_features.mk
+++ b/common_features.mk
@@ -367,6 +367,10 @@ ifeq ($(strip $(USB_HID_ENABLE)), yes)
     include $(TMK_DIR)/protocol/usb_hid.mk
 endif
 
+ifeq ($(strip $(WPM_ENABLE)), yes)
+    SRC += $(QUANTUM_DIR)/wpm.c
+    OPT_DEFS += -DWPM_ENABLE
+endif
 
 ifeq ($(strip $(ENCODER_ENABLE)), yes)
     SRC += $(QUANTUM_DIR)/encoder.c
diff --git a/quantum/quantum.c b/quantum/quantum.c
index 0ada2fa9b0..b31c98852c 100644
--- a/quantum/quantum.c
+++ b/quantum/quantum.c
@@ -189,6 +189,12 @@ bool process_record_quantum(keyrecord_t *record) {
     }
 #endif
 
+#ifdef WPM_ENABLE
+    if (record->event.pressed) {
+	update_wpm(keycode);
+    }
+#endif
+
 #ifdef TAP_DANCE_ENABLE
     preprocess_tap_dance(keycode, record);
 #endif
@@ -658,6 +664,10 @@ void matrix_scan_quantum() {
     encoder_read();
 #endif
 
+#ifdef WPM_ENABLE
+  decay_wpm();
+#endif
+
 #ifdef HAPTIC_ENABLE
     haptic_task();
 #endif
diff --git a/quantum/quantum.h b/quantum/quantum.h
index 69c8d2151f..e811616f0e 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -187,6 +187,10 @@ extern layer_state_t layer_state;
 #    include "via.h"
 #endif
 
+#ifdef WPM_ENABLE
+#    include "wpm.h"
+#endif
+
 // Function substitutions to ease GPIO manipulation
 #if defined(__AVR__)
 typedef uint8_t pin_t;
diff --git a/quantum/split_common/transport.c b/quantum/split_common/transport.c
index 3c783dc568..487dbcae64 100644
--- a/quantum/split_common/transport.c
+++ b/quantum/split_common/transport.c
@@ -35,6 +35,9 @@ typedef struct _I2C_slave_buffer_t {
 #    ifdef ENCODER_ENABLE
     uint8_t encoder_state[NUMBER_OF_ENCODERS];
 #    endif
+#    ifdef WPM_ENABLE
+    uint8_t current_wpm;
+#    endif
 } I2C_slave_buffer_t;
 
 static I2C_slave_buffer_t *const i2c_buffer = (I2C_slave_buffer_t *)i2c_slave_reg;
@@ -43,6 +46,7 @@ static I2C_slave_buffer_t *const i2c_buffer = (I2C_slave_buffer_t *)i2c_slave_re
 #    define I2C_RGB_START offsetof(I2C_slave_buffer_t, rgblight_sync)
 #    define I2C_KEYMAP_START offsetof(I2C_slave_buffer_t, smatrix)
 #    define I2C_ENCODER_START offsetof(I2C_slave_buffer_t, encoder_state)
+#    define I2C_WPM_START offsetof(I2C_slave_buffer_t, current_wpm)
 
 #    define TIMEOUT 100
 
@@ -79,6 +83,14 @@ bool transport_master(matrix_row_t matrix[]) {
     encoder_update_raw(i2c_buffer->encoder_state);
 #    endif
 
+#    ifdef WPM_ENABLE
+    uint8_t current_wpm = get_current_wpm();
+    if(current_wpm != i2c_buffer->current_wpm) {
+        if (i2c_writeReg(SLAVE_I2C_ADDRESS, I2C_WPM_START, (void *)&current_wpm, sizeof(current_wpm), TIMEOUT) >= 0) {
+            i2c_buffer->current_wpm = current_wpm;
+        }
+    }
+#    endif
     return true;
 }
 
@@ -102,6 +114,10 @@ void transport_slave(matrix_row_t matrix[]) {
 #    ifdef ENCODER_ENABLE
     encoder_state_raw(i2c_buffer->encoder_state);
 #    endif
+
+#    ifdef WPM_ENABLE
+    set_current_wpm(i2c_buffer->current_wpm);
+#    endif
 }
 
 void transport_master_init(void) { i2c_init(); }
@@ -126,6 +142,9 @@ typedef struct _Serial_m2s_buffer_t {
 #    ifdef BACKLIGHT_ENABLE
     uint8_t backlight_level;
 #    endif
+#    ifdef WPM_ENABLE
+    uint8_t current_wpm;
+#    endif
 } Serial_m2s_buffer_t;
 
 #    if defined(RGBLIGHT_ENABLE) && defined(RGBLIGHT_SPLIT)
@@ -228,6 +247,10 @@ bool transport_master(matrix_row_t matrix[]) {
     encoder_update_raw((uint8_t *)serial_s2m_buffer.encoder_state);
 #    endif
 
+#    ifdef WPM_ENABLE
+    // Write wpm to slave
+    serial_m2s_buffer.current_wpm = get_current_wpm();
+#    endif
     return true;
 }
 
@@ -244,6 +267,10 @@ void transport_slave(matrix_row_t matrix[]) {
 #    ifdef ENCODER_ENABLE
     encoder_state_raw((uint8_t *)serial_s2m_buffer.encoder_state);
 #    endif
+
+#    ifdef WPM_ENABLE
+     set_current_wpm(serial_m2s_buffer.current_wpm);
+#    endif
 }
 
 #endif
diff --git a/quantum/wpm.c b/quantum/wpm.c
new file mode 100644
index 0000000000..d4c971f313
--- /dev/null
+++ b/quantum/wpm.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2020 Richard Sutherland (rich@brickbots.com)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "wpm.h"
+
+//WPM Stuff
+static uint8_t current_wpm = 0;
+static uint8_t latest_wpm = 0;
+static uint16_t wpm_timer = 0;
+
+//This smoothing is 40 keystrokes
+static const float wpm_smoothing = 0.0487;
+
+void set_current_wpm(uint8_t new_wpm) { current_wpm = new_wpm; }
+
+uint8_t get_current_wpm(void) { return current_wpm; }
+
+bool wpm_keycode(uint16_t keycode) { return wpm_keycode_kb(keycode); }
+
+__attribute__((weak)) bool wpm_keycode_kb(uint16_t keycode) { return wpm_keycode_user(keycode); }
+
+__attribute__((weak)) bool wpm_keycode_user(uint16_t keycode) {
+
+    if ((keycode >= QK_MOD_TAP && keycode <= QK_MOD_TAP_MAX) || (keycode >= QK_LAYER_TAP && keycode <= QK_LAYER_TAP_MAX) || (keycode >= QK_MODS && keycode <= QK_MODS_MAX)) {
+        keycode = keycode & 0xFF;
+    } else if (keycode > 0xFF) {
+	keycode = 0;
+    }
+    if((keycode >= KC_A && keycode <= KC_0) || (keycode >= KC_TAB && keycode <= KC_SLASH)) {
+	return true;
+    }
+
+    return false;
+}
+
+
+void update_wpm(uint16_t keycode) {
+    if(wpm_keycode(keycode)) {
+	if(wpm_timer > 0) {
+	    latest_wpm = 60000 / timer_elapsed(wpm_timer) / 5;
+	    current_wpm = (latest_wpm - current_wpm) * wpm_smoothing + current_wpm;
+	}
+	wpm_timer = timer_read();
+    }
+}
+
+void decay_wpm(void) {
+  if (timer_elapsed(wpm_timer) > 1000) {
+	current_wpm = (0 - current_wpm) * wpm_smoothing +
+		current_wpm;
+	wpm_timer = timer_read();
+  }
+}
diff --git a/quantum/wpm.h b/quantum/wpm.h
new file mode 100644
index 0000000000..fa0b6d1288
--- /dev/null
+++ b/quantum/wpm.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2020 Richard Sutherland (rich@brickbots.com)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "quantum.h"
+
+bool wpm_keycode(uint16_t keycode);
+bool wpm_keycode_kb(uint16_t keycode);
+bool wpm_keycode_user(uint16_t keycode);
+
+void set_current_wpm(uint8_t);
+uint8_t get_current_wpm(void);
+void update_wpm(uint16_t);
+
+void decay_wpm(void);