diff --git a/drivers/gpio/sn74x154.c b/drivers/gpio/sn74x154.c
new file mode 100644
index 0000000000..5f21f12b55
--- /dev/null
+++ b/drivers/gpio/sn74x154.c
@@ -0,0 +1,58 @@
+/* Copyright 2022
+ *
+ * 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 .
+ */
+
+#include "sn74x154.h"
+#include "gpio.h"
+
+#define ADDRESS_PIN_COUNT 4
+
+#ifndef SN74X154_ADDRESS_PINS
+# error sn74x154: no address pins defined!
+#endif
+
+static const pin_t address_pins[ADDRESS_PIN_COUNT] = SN74X154_ADDRESS_PINS;
+
+void sn74x154_init(void) {
+ for (int i = 0; i < ADDRESS_PIN_COUNT; i++) {
+ setPinOutput(address_pins[i]);
+ writePinLow(address_pins[i]);
+ }
+
+#if defined(SN74X154_E0_PIN)
+ setPinOutput(SN74X154_E0_PIN);
+ writePinHigh(SN74X154_E0_PIN);
+#endif
+
+#if defined(SN74X154_E1_PIN)
+ setPinOutput(SN74X154_E1_PIN);
+ writePinHigh(SN74X154_E1_PIN);
+#endif
+}
+
+void sn74x154_set_enabled(bool enabled) {
+#if defined(SN74X154_E0_PIN)
+ writePin(SN74X154_E0_PIN, !enabled);
+#endif
+#if defined(SN74X154_E1_PIN)
+ writePin(SN74X154_E1_PIN, !enabled);
+#endif
+}
+
+void sn74x154_set_addr(uint8_t address) {
+ for (int i = 0; i < ADDRESS_PIN_COUNT; i++) {
+ writePin(address_pins[i], address & (1 << i));
+ }
+}
diff --git a/drivers/gpio/sn74x154.h b/drivers/gpio/sn74x154.h
new file mode 100644
index 0000000000..ce6a9ddb0e
--- /dev/null
+++ b/drivers/gpio/sn74x154.h
@@ -0,0 +1,48 @@
+/* Copyright 2022
+ *
+ * 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 .
+ */
+
+#pragma once
+
+#include
+#include
+
+/**
+ * Driver for 74x154 4-to-16 decoder/demultiplexer with inverting outputs
+ * https://assets.nexperia.com/documents/data-sheet/74HC_HCT154.pdf
+ */
+
+/**
+ * Initialize the address and output enable pins.
+ */
+void sn74x154_init(void);
+
+/**
+ * Set the enabled state.
+ *
+ * When enabled is true, pulls the E0 and E1 pins low.
+ *
+ * \param enabled The enable state to set.
+ */
+void sn74x154_set_enabled(bool enabled);
+
+/**
+ * Set the output pin address.
+ *
+ * The selected output pin will be pulled low, while the remaining output pins will be high.
+ *
+ * \param address The address to set, from 0 to 15.
+ */
+void sn74x154_set_addr(uint8_t address);
diff --git a/keyboards/al1/config.h b/keyboards/al1/config.h
index c8edb8ebfe..570eb03ae2 100644
--- a/keyboards/al1/config.h
+++ b/keyboards/al1/config.h
@@ -30,6 +30,11 @@ along with this program. If not, see .
#define MATRIX_ROWS 6
#define MATRIX_COLS 16
+#define MATRIX_ROW_PINS { C7, B1, B2, C6, B4, B5 }
+
+#define SN74X154_ADDRESS_PINS { D4, D5, D6, D7 }
+#define SN74X154_E1_PIN D3
+
#define LED_NUM_LOCK_PIN D0
#define LED_CAPS_LOCK_PIN B7
#define LED_SCROLL_LOCK_PIN D1
diff --git a/keyboards/al1/matrix.c b/keyboards/al1/matrix.c
index 1407cbc089..e3d7971f1c 100644
--- a/keyboards/al1/matrix.c
+++ b/keyboards/al1/matrix.c
@@ -1,91 +1,101 @@
+/* Copyright 2022
+ *
+ * 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 .
+ */
+
#include "matrix.h"
-
#include "gpio.h"
+#include "sn74x154.h"
-static uint8_t read_rows(void) {
- return (readPin(C7) ? 0 : 1) |
- (readPin(B1) ? 0 : 2) |
- (readPin(B2) ? 0 : 4) |
- (readPin(C6) ? 0 : 8) |
- (readPin(B4) ? 0 : 16) |
- (readPin(B5) ? 0 : 32);
-}
+static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
+/* All columns use a 74HC154 4-to-16 demultiplexer.
+ * D3 is the enable pin, must be set high to use it.
+ *
+ * A3 A2 A1 A0
+ * D7 D6 D5 D4
+ * 0: 0 0 0 0
+ * 1: 0 0 0 1
+ * 2: 0 0 1 0
+ * 3: 0 0 1 1
+ * 4: 0 1 0 0
+ * 5: 0 1 0 1
+ * 6: 0 1 1 0
+ * 7: 0 1 1 1
+ * 8: 1 0 0 0
+ * 9: 1 0 0 1
+ * 10: 1 0 1 0
+ * 11: 1 0 1 1
+ * 12: 1 1 0 0
+ * 13: 1 1 0 1
+ * 14: 1 1 1 0
+ * 15: 1 1 1 1
+ */
static void select_col(uint8_t col) {
- writePinLow(D3);
-
- writePin(D4, (col & 1));
- writePin(D5, (col & 2));
- writePin(D6, (col & 4));
- writePin(D7, (col & 8));
+ sn74x154_set_addr(col);
}
-static void unselect_cols(void) {
- writePinHigh(D3);
+static void init_pins(void) {
+ for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
+ setPinInputHigh(row_pins[x]);
+ }
+}
+
+static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) {
+ bool matrix_changed = false;
+
+ // Select col and wait for col seleciton to stabilize
+ select_col(current_col);
+ matrix_io_delay();
+
+ // For each row...
+ for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) {
+ // Store last value of row prior to reading
+ matrix_row_t last_row_value = current_matrix[row_index];
+
+ // Check row pin state
+ if (readPin(row_pins[row_index]) == 0) {
+ // Pin LO, set col bit
+ current_matrix[row_index] |= (MATRIX_ROW_SHIFTER << current_col);
+ } else {
+ // Pin HI, clear col bit
+ current_matrix[row_index] &= ~(MATRIX_ROW_SHIFTER << current_col);
+ }
+
+ // Determine if the matrix changed state
+ if ((last_row_value != current_matrix[row_index]) && !(matrix_changed)) {
+ matrix_changed = true;
+ }
+ }
+
+ return matrix_changed;
}
void matrix_init_custom(void) {
- /* 74HC154 col pin configuration
- * pin: D3 D7 D6 D5 D4
- * row: off 0 x x x x
- * 0 1 0 0 0 0
- * 1 1 0 0 0 1
- * 2 1 0 0 1 0
- * 3 1 0 0 1 1
- * 4 1 0 1 0 0
- * 5 1 0 1 0 1
- * 6 1 0 1 1 0
- * 7 1 0 1 1 1
- * 8 1 1 0 0 0
- * 9 1 1 0 0 1
- * 10 1 1 0 1 0
- * 11 1 1 0 1 1
- * 12 1 1 1 0 0
- * 13 1 1 1 0 1
- * 14 1 1 1 1 0
- * 15 1 1 1 1 1
- */
- setPinOutput(D3);
- writePinHigh(D3);
-
- setPinOutput(D4);
- setPinOutput(D5);
- setPinOutput(D6);
- setPinOutput(D7);
-
-
- /* Row pin configuration
- *
- * row: 0 1 2 3 4 5
- * pin: C7 B1 B2 C6 B4 B5
- *
- */
- setPinInputHigh(C7);
- setPinInputHigh(B1);
- setPinInputHigh(B2);
- setPinInputHigh(C6);
- setPinInputHigh(B4);
- setPinInputHigh(B5);
+ // initialize demultiplexer
+ sn74x154_init();
+ sn74x154_set_enabled(true);
+ // initialize key pins
+ init_pins();
}
bool matrix_scan_custom(matrix_row_t current_matrix[]) {
bool changed = false;
- for (uint8_t col = 0; col < MATRIX_COLS; col++) {
- select_col(col);
- matrix_io_delay();
- uint8_t rows = read_rows();
-
- for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
- bool prev_bit = current_matrix[row] & ((matrix_row_t)1 << col);
- bool curr_bit = rows & (1 << row);
-
- if (prev_bit != curr_bit) {
- current_matrix[row] ^= ((matrix_row_t)1 << col);
- changed = true;
- }
- }
- unselect_cols();
+ // Set col, read rows
+ for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) {
+ changed |= read_rows_on_col(current_matrix, current_col);
}
return changed;
diff --git a/keyboards/al1/rules.mk b/keyboards/al1/rules.mk
index 670712f661..1f8e81de20 100644
--- a/keyboards/al1/rules.mk
+++ b/keyboards/al1/rules.mk
@@ -18,4 +18,5 @@ RGBLIGHT_ENABLE = no # Enable keyboard RGB underglow
AUDIO_ENABLE = no # Audio output
CUSTOM_MATRIX = lite
-SRC += matrix.c
+VPATH += drivers/gpio
+SRC += matrix.c sn74x154.c