[Keyboard] Update Symmetric70 keyboard prototype (#12707)

* update handwired/symmetric70_proto/matrix.c

* make keyboards/handwired/symmetric70_proto/promicro/

* add symmetric70_proto/debug_config.h, update symmetric70_proto/local_features.mk etc.

  set MATRIX_IO_DELAY macro
    make MTEST=mdelay0  symmetric70_proto/promicro:default:flash
    make MTEST=mdelay1  symmetric70_proto/promicro:default:flash
    make MTEST=mdelay10 symmetric70_proto/promicro:default:flash
    make MTEST=mdelay30 symmetric70_proto/promicro:default:flash
  set DEBUG_MATRIX_SCAN_RATE_ENABLE yes
    make MTEST=scan symmetric70_proto/promicro:default:flash
  set MATRIX_DEBUG_DELAY and MATRIX_IO_DELAY macro
    make MTEST=matrix_debug_delay,mdelay0 symmetric70_proto/promicro:default:flash
  set MATRIX_DEBUG_SCAN
    make MTEST=matrix_debug_scan symmetric70_proto/promicro:default:flash

* add symmetric70_proto/matrix_debug/readme.md

* update symmetric70_proto/matrix_debug/readme.md

* update handwired/symmetric70_proto/readme.md

* update handwired/symmetric70_proto/readme.md

* update handwired/symmetric70_proto/*/readme.md

* add handwired/symmetric70_proto/matrix_fast/

* update handwired/symmetric70_proto/matrix_fast/readme.md

* fix typo in handwired/symmetric70_proto/matrix_fast/readme.md

* update config.h under handwired/symmetric70_proto/promicro

* add Proton C support to handwired/symmetric70_proto

* add handwired/symmetric70_proto/proton_c/readme.md

* add promicro/*/readme.md proton_c/*/readme.md

* update handwired/symmetric70_proto/proton_c/proton_c.c

support MATRIX_IO_DELAY_DEFAULT for testing.

* Added another implementation of 'adaptive_delay'.

* update symmetric70_proto/local_features.mk

* update symmetric70_proto/matrix_fast/gpio_extr.h

* add matrix_output_unselect_delay_ports()

* add MTEST=adaptive_delay_fast option

* update symmetric70_proto/matrix_debug/readme.md

* update symmetric70_proto/matrix_fast/readme.md

* update symmetric70_proto/matrix_debug/readme.md

* Erase garbage

* fix symmetric70_proto/proton_c/proton_c.c

* improve adaptive_delay_fast in symmetric70_proto/matrix_debug/matrix.c

* update symmetric70_proto/matrix_debug/readme.md

* fix symmetric70_proto/matrix_debug/readme.md

* Update keyboards/handwired/symmetric70_proto/proton_c/rules.mk

Co-authored-by: Ryan <fauxpark@gmail.com>

* Update keyboards/handwired/symmetric70_proto/proton_c/rules.mk

Co-authored-by: Ryan <fauxpark@gmail.com>

* Update keyboards/handwired/symmetric70_proto/local_features.mk

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/local_features.mk

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_debug/matrix.c

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_debug/matrix.c

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/local_features.mk

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_debug/matrix.c

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_debug/readme.md

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_debug/readme.md

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_debug/readme.md

Co-authored-by: Nick Brassel <nick@tzarc.org>

* Update keyboards/handwired/symmetric70_proto/matrix_fast/matrix_config_expand.c

Co-authored-by: Nick Brassel <nick@tzarc.org>

Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: Nick Brassel <nick@tzarc.org>

10 files changed, 908 insertions, 0 deletions

diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/cpp_map.h b/keyboards/handwired/symmetric70_proto/matrix_fast/cpp_map.h
new file mode 100644
index 0000000000..d197be6d9f
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/cpp_map.h
@@ -0,0 +1,53 @@
+/* Copyright 2021 mtei
+ *
+ * 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
+// clang-format off
+
+#define _MAP1(E, _1) E(_1)
+#define _MAP2(E, _1,_2) E(_1) E(_2)
+#define _MAP3(E, _1,_2,_3) E(_1) E(_2) E(_3)
+#define _MAP4(E, _1,_2,_3,_4) E(_1) E(_2) E(_3) E(_4)
+#define _MAP5(E, _1,_2,_3,_4,_5) E(_1) E(_2) E(_3) E(_4) E(_5)
+#define _MAP6(E, _1,_2,_3,_4,_5,_6) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6)
+#define _MAP7(E, _1,_2,_3,_4,_5,_6,_7) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7)
+#define _MAP8(E, _1,_2,_3,_4,_5,_6,_7,_8) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8)
+#define _MAP9(E, _1,_2,_3,_4,_5,_6,_7,_8,_9) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9)
+#define _MAP10(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10)
+#define _MAP11(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11)
+#define _MAP12(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12)
+#define _MAP13(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13)
+#define _MAP14(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14)
+#define _MAP15(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15)
+#define _MAP16(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16)
+#define _MAP17(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17)
+#define _MAP18(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18)
+#define _MAP19(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19)
+#define _MAP20(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20)
+#define _MAP21(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21)
+#define _MAP22(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22)
+#define _MAP23(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23)
+#define _MAP24(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24)
+#define _MAP25(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25)
+#define _MAP26(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26)
+#define _MAP27(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26) E(_27)
+#define _MAP28(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26) E(_27) E(_28)
+#define _MAP29(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26) E(_27) E(_28) E(_29)
+#define _MAP30(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29,_30) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26) E(_27) E(_28) E(_29) E(_30)
+#define _MAP31(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29,_30,_31) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26) E(_27) E(_28) E(_29) E(_30) E(_31)
+#define _MAP32(E, _1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29,_30,_31,_32) E(_1) E(_2) E(_3) E(_4) E(_5) E(_6) E(_7) E(_8) E(_9) E(_10) E(_11) E(_12) E(_13) E(_14) E(_15) E(_16) E(_17) E(_18) E(_19) E(_20) E(_21) E(_22) E(_23) E(_24) E(_25) E(_26) E(_27) E(_28) E(_29) E(_30) E(_31) E(_32)
+
+#define SELECT_MAP(e,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29,_30,_31,_32,NAME,...) NAME
+#define MAP(E,...) SELECT_MAP(E,__VA_ARGS__,_MAP32,_MAP31,_MAP30,_MAP29,_MAP28,_MAP27,_MAP26,_MAP25,_MAP24,_MAP23,_MAP22,_MAP21,_MAP20,_MAP19,_MAP18,_MAP17,_MAP16,_MAP15,_MAP14,_MAP13,_MAP12,_MAP11,_MAP10,_MAP9,_MAP8,_MAP7,_MAP6,_MAP5,_MAP4,_MAP3,_MAP2,_MAP1)(E,__VA_ARGS__)
diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/gpio_extr.h b/keyboards/handwired/symmetric70_proto/matrix_fast/gpio_extr.h
new file mode 100644
index 0000000000..e31cb5f3a5
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/gpio_extr.h
@@ -0,0 +1,28 @@
+#pragma once
+// clang-format off
+
+#if defined(__AVR__)
+typedef uint8_t     port_data_t;
+
+#define readPort(port)                 PINx_ADDRESS(port)
+
+#define setPortBitInput(port, bit)     (DDRx_ADDRESS(port) &= ~_BV((bit)&0xF), PORTx_ADDRESS(port) &= ~_BV((bit)&0xF))
+#define setPortBitInputHigh(port, bit) (DDRx_ADDRESS(port) &= ~_BV((bit)&0xF), PORTx_ADDRESS(port) |= _BV((bit)&0xF))
+#define setPortBitOutput(port, bit)    (DDRx_ADDRESS(port) |= _BV((bit)&0xF))
+
+#define writePortBitLow(port, bit)     (PORTx_ADDRESS(port) &= ~_BV((bit)&0xF))
+#define writePortBitHigh(port, bit)    (PORTx_ADDRESS(port) |= _BV((bit)&0xF))
+
+#else
+typedef uint16_t     port_data_t;
+
+#define readPort(qmk_pin)                 palReadPort(PAL_PORT(qmk_pin))
+
+#define setPortBitInput(qmk_pin, bit)     palSetPadMode(PAL_PORT(qmk_pin), bit, PAL_MODE_INPUT)
+#define setPortBitInputHigh(qmk_pin, bit) palSetPadMode(PAL_PORT(qmk_pin), bit, PAL_MODE_INPUT_PULLUP)
+#define setPortBitInputLow(qmk_pin, bit)  palSetPadMode(PAL_PORT(qmk_pin), bit, PAL_MODE_INPUT_PULLDOWN)
+#define setPortBitOutput(qmk_pin, bit)    palSetPadMode(PAL_PORT(qmk_pin), bit, PAL_MODE_OUTPUT_PUSHPULL)
+
+#define writePortBitLow(qmk_pin, bit)     palClearLine(PAL_LINE(PAL_PORT(qmk_pin), bit))
+#define writePortBitHigh(qmk_pin, bit)    palSetLine(PAL_LINE(PAL_PORT(qmk_pin), bit))
+#endif
diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/matrix.c b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix.c
new file mode 100644
index 0000000000..cb21bfcf8d
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix.c
@@ -0,0 +1,234 @@
+/*
+Copyright 2021 mtei
+
+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/>.
+*/
+// clang-format off
+#include <stdint.h>
+#include <stdbool.h>
+#include <gpio.h>
+#ifndef readPort
+#    include "gpio_extr.h"
+#endif
+#include "util.h"
+#include "matrix.h"
+#include "matrix_extr.h"
+#include "debounce.h"
+#include "quantum.h"
+
+#define ALWAYS_INLINE inline __attribute__((always_inline))
+#define NO_INLINE     __attribute__((noinline))
+#define LOCAL_FUNC static
+#define LOCAL_DATA static
+
+#ifndef _BV
+#    define _BV(bit) (1 << (bit))
+#endif
+
+#ifndef MATRIX_DEBUG_PIN
+#    define MATRIX_DEBUG_PIN_INIT()
+#    define MATRIX_DEBUG_SCAN_START()
+#    define MATRIX_DEBUG_SCAN_END()
+#    define MATRIX_DEBUG_DELAY_START()
+#    define MATRIX_DEBUG_DELAY_END()
+#    define MATRIX_DEBUG_GAP()
+#else
+#    define MATRIX_DEBUG_GAP()  asm volatile("nop \n nop":::"memory")
+#endif
+
+typedef uint16_t     port_width_t;
+#if MATRIX_TYPE == DIRECT_SWITCH || MATRIX_TYPE == DIODE_COL2ROW
+#    define MATRIX_LINES MATRIX_ROWS
+typedef matrix_row_t matrix_line_t;
+#endif
+#if MATRIX_TYPE == DIODE_ROW2COL
+#    define MATRIX_LINES MATRIX_COLS
+typedef matrix_col_t matrix_line_t;
+#endif
+typedef struct _port_descriptor {
+    int device;
+    pin_t port;
+} port_descriptor;
+
+/* matrix state(1:on, 0:off) */
+extern matrix_row_t raw_matrix[MATRIX_ROWS];  // raw values
+extern matrix_row_t matrix[MATRIX_ROWS];      // debounced values
+
+#define setPortBitOutput_writeLow(port, bit) \
+    do { setPortBitOutput(port, bit); writePortBitLow(port, bit); } while(0)
+#define setPortBitOutput_writeLow_atomic(port, bit) \
+    do { ATOMIC_BLOCK_FORCEON { setPortBitOutput_writeLow(port, bit); } } while(0)
+#define setPortBitInputHigh_atomic(port, bit) \
+    do { ATOMIC_BLOCK_FORCEON { setPortBitInputHigh(port, bit); } } while(0)
+
+#if defined(MATRIX_IN_PORTS) && defined(MATRIX_IN_PINS)
+#   include "matrix_config_expand.c"
+#else
+#   error matrix.c need defined MATRIX_IN_PORTS and MATRIX_IN_PINS
+#endif
+
+LOCAL_FUNC
+void unselect_output(uint8_t out_index) {
+    unselect_output_inline(out_index);
+}
+
+LOCAL_FUNC
+void init_output_ports(void) {
+    for (int i = 0; i < END_outpin_index; i++) {
+        unselect_output(i);
+    }
+}
+
+LOCAL_FUNC
+void init_all_ports(void) {
+    init_input_ports();
+    init_output_ports();
+    init_inport_mask();
+    init_extension();
+}
+
+LOCAL_FUNC ALWAYS_INLINE void select_line_and_read_input_ports(uint8_t current_line, port_width_t port_buffer[NUM_OF_INPUT_PORTS]);
+LOCAL_FUNC void select_line_and_read_input_ports(uint8_t current_line, port_width_t port_buffer[NUM_OF_INPUT_PORTS]) {
+    // Select row (or col)
+    select_output(current_line);
+    matrix_output_select_delay();
+
+    // Read ports
+    read_all_input_ports(port_buffer, false);
+
+    // Unselect row (or col)
+    unselect_output_inline(current_line);
+}
+
+LOCAL_FUNC ALWAYS_INLINE void read_matrix_line(matrix_line_t phy_matrix[], uint8_t current_line);
+
+#if MATRIX_TYPE == DIODE_ROW2COL || MATRIX_TYPE == DIODE_COL2ROW
+LOCAL_FUNC void read_matrix_line(matrix_line_t phy_matrix[], uint8_t current_line) {
+    // Start with a clear matrix row
+    matrix_line_t current_line_value = 0;
+    port_width_t port_buffer[NUM_OF_INPUT_PORTS];
+
+#ifdef MATRIX_GPIO_NEED_SEPARATE_ATOMIC
+    select_line_and_read_input_ports(current_line, port_buffer);
+#else
+    ATOMIC_BLOCK_FORCEON {
+        select_line_and_read_input_ports(current_line, port_buffer);
+    }
+#endif
+
+    // Build row (or col)
+    current_line_value = build_matrix_line(port_buffer);
+
+    // Wait signal raise up
+    if (current_line_value) {
+        MATRIX_DEBUG_DELAY_START();
+        wait_unselect_done();
+        MATRIX_DEBUG_DELAY_END();
+    }
+    phy_matrix[current_line] = current_line_value;
+}
+#endif // MATRIX_TYPE == DIODE_ROW2COL || MATRIX_TYPE == DIODE_COL2ROW
+
+#if MATRIX_TYPE == DIRECT_SWITCH
+LOCAL_FUNC void read_matrix_line(matrix_line_t phy_matrix[], uint8_t current_line) {
+    port_width_t port_buffer[NUM_OF_INPUT_PORTS];
+
+    if (current_line != 0) {
+        return;
+    }
+
+    for (uint8_t i = 0; i < MATRIX_LINES; i++) {
+        phy_matrix[i] = 0;
+    }
+
+    read_all_input_ports(port_buffer, false);
+
+    // Build matrix
+    build_matrix_direct(port_buffer, phy_matrix);
+}
+#endif // MATRIX_TYPE == DIRECT_SWITCH
+
+void matrix_init(void) {
+    // initialize key pins
+    init_all_ports();
+
+    // initialize matrix state: all keys off
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+        raw_matrix[i] = 0;
+        matrix[i]     = 0;
+    }
+
+    debounce_init(MATRIX_ROWS);
+
+    matrix_init_quantum();
+}
+
+uint8_t matrix_scan(void) {
+    matrix_line_t phy_matrix[MATRIX_LINES];
+
+    MATRIX_DEBUG_PIN_INIT();
+
+    MATRIX_DEBUG_SCAN_START();
+
+    // read I/O port to phy_matrix[] (physical matrix)
+    //select line, read inputs
+    for (uint8_t current_line = 0; current_line < MATRIX_LINES; current_line++) {
+        read_matrix_line(phy_matrix, current_line);
+    }
+    MATRIX_DEBUG_SCAN_END(); MATRIX_DEBUG_GAP(); MATRIX_DEBUG_SCAN_START();
+
+    bool changed = false;
+#if MATRIX_TYPE == DIRECT_SWITCH || MATRIX_TYPE == DIODE_COL2ROW
+    // copy phy_matrix[] to raw_matrix[]
+    for (uint8_t current_line = 0; current_line < MATRIX_ROWS; current_line++) {
+        if (raw_matrix[current_line] != phy_matrix[current_line]) {
+            changed = true;
+            raw_matrix[current_line] = phy_matrix[current_line];
+        }
+    }
+#endif
+#if MATRIX_TYPE == DIODE_ROW2COL
+    // transpose phy_matrix[] to raw_matrix[]
+    matrix_row_t trans_matrix[MATRIX_ROWS];
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++ ) {
+        trans_matrix[i] = 0;
+    }
+    for (uint8_t src_line = 0; src_line < MATRIX_LINES; src_line++) {
+        matrix_line_t src_line_data = phy_matrix[src_line];
+        matrix_row_t dist_bit = MATRIX_ROW_SHIFTER << src_line;
+        for (uint8_t dist_rows = 0; dist_rows < MATRIX_ROWS; dist_rows++) {
+            if ((src_line_data & 1) == 1) {
+                trans_matrix[dist_rows] |= dist_bit;
+            }
+            src_line_data >>= 1;
+        }
+    }
+    for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
+        if (raw_matrix[current_row] != trans_matrix[current_row]) {
+            changed = true;
+            raw_matrix[current_row] = trans_matrix[current_row];
+        }
+    }
+#endif
+    MATRIX_DEBUG_SCAN_END(); MATRIX_DEBUG_GAP(); MATRIX_DEBUG_SCAN_START();
+
+    // debounce raw_matrix[] to matrix[]
+    debounce(raw_matrix, matrix, MATRIX_ROWS, changed);
+    MATRIX_DEBUG_SCAN_END(); MATRIX_DEBUG_GAP();
+
+    MATRIX_DEBUG_SCAN_START();
+    matrix_scan_quantum();
+    MATRIX_DEBUG_SCAN_END();
+    return (uint8_t)changed;
+}
diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_config_expand.c b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_config_expand.c
new file mode 100644
index 0000000000..0df605db47
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_config_expand.c
@@ -0,0 +1,234 @@
+/*
+Copyright 2021 mtei
+
+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/>.
+*/
+// clang-format off
+
+#include "matrix_extr.h"
+
+#ifdef DEBUG_MATRIX_CONFIG
+// config expand debug
+//   avr-gcc -DDEBUG_MATRIX_CONFIG=\"test_config.h\" -E -C matrix_config_expand.c
+#    include DEBUG_MATRIX_CONFIG
+#endif
+
+#undef NO_PIN /* cancel NO_PIN define in tmk_core/common/pin_defs.h */
+#define NO_PIN  NO_PORT, 0
+#if MATRIX_TYPE == DIRECT_SWITCH
+#    undef MATRIX_OUT_PORTS
+#    define MATRIX_OUT_PINS  (0, NO_PIN)
+#endif
+
+#include "cpp_map.h"
+
+#if defined(MATRIX_EXTENSION_74HC157) || defined(MATRIX_EXTENSION_74HC153)
+#   define  MATRIX_EXTENSION "matrix_extension_74hc15x.c"
+#endif
+
+#ifdef MATRIX_EXTENSION
+#    include MATRIX_EXTENSION
+#endif
+
+#ifdef MATRIX_GPIO_NEED_SEPARATE_ATOMIC
+#    ifndef setMatrixInputHigh
+#        define setMatrixInputHigh(dev, port, bit) do { if ((dev) == MCU_GPIO) { setPortBitInputHigh_atomic(port, bit); }} while(0)
+#    endif
+#    ifndef setMatrixOutput_writeHighZ
+#        define setMatrixOutput_writeHighZ(dev, port, bit) do { if ((dev) == MCU_GPIO) { setPortBitInputHigh_atomic(port, bit); }} while(0)
+#    endif
+#    ifndef setMatrixOutput_writeLow
+#        define setMatrixOutput_writeLow(dev, port, bit) do { if ((dev) == MCU_GPIO) { setPortBitOutput_writeLow_atomic(port, bit); }} while(0)
+#    endif
+#else
+#    ifndef setMatrixInputHigh
+#        define setMatrixInputHigh(dev, port, bit) do { if ((dev) == MCU_GPIO) { setPortBitInputHigh(port, bit); }} while(0)
+#    endif
+#    ifndef setMatrixOutput_writeHighZ
+#        define setMatrixOutput_writeHighZ(dev, port, bit) do { if ((dev) == MCU_GPIO) { setPortBitInputHigh(port, bit); }} while(0)
+#    endif
+#    ifndef setMatrixOutput_writeLow
+#        define setMatrixOutput_writeLow(dev, port, bit) do { if ((dev) == MCU_GPIO) { setPortBitOutput_writeLow(port, bit); }} while(0)
+#    endif
+#endif
+
+#ifndef readMatrixPort
+#    define readMatrixPort(dev, port) (((dev) == MCU_GPIO) ? readPort(port) : 0)
+#endif
+#ifndef getMatrixInputMaskBit
+#    define getMatrixInputMaskBit(dev, bit) (((dev) != NO_DEVICE) ? _BV((bit)&0xF) : 0)
+#endif
+
+#ifndef init_extension
+#    define init_extension()
+#endif
+
+enum DEVICE_NAME {
+    MCU_GPIO,
+    NO_DEVICE,
+#ifdef MATRIX_DEVICES
+    MATRIX_DEVICES
+#endif
+};
+
+#define _INPUT_PORTS_ENUM_ELEMENT(name, dev, port) inport_index_##name,
+#define INPUT_PORTS_ENUM_ELEMENT(x) _INPUT_PORTS_ENUM_ELEMENT x
+enum INPUT_PORTS {
+    INPUT_PORTS_ENUM_ELEMENT((NO_PORT, NO_DEVICE, 0))
+    MAP(INPUT_PORTS_ENUM_ELEMENT, MATRIX_IN_PORTS)
+    NUM_OF_INPUT_PORTS
+};
+
+#define _INPUT_PINS_ENUM_ELEMENT(index, port, bit) inpin_index_##index,
+#define INPUT_PINS_ENUM_ELEMENT(x) _INPUT_PINS_ENUM_ELEMENT x
+enum INPUT_PINS {
+    MAP(INPUT_PINS_ENUM_ELEMENT, MATRIX_IN_PINS)
+    END_inpin_index
+};
+
+#define _OUTPUT_PORTS_ENUM_ELEMENT(name, dev, port) outport_index_##name,
+#define OUTPUT_PORTS_ENUM_ELEMENT(x) _OUTPUT_PORTS_ENUM_ELEMENT x
+enum OUTPUT_PORTS {
+    OUTPUT_PORTS_ENUM_ELEMENT((NO_PORT, NO_DEVICE, 0))
+#ifdef MATRIX_OUT_PORTS
+    MAP(OUTPUT_PORTS_ENUM_ELEMENT, MATRIX_OUT_PORTS)
+#endif
+    NUM_OF_OUTPUT_PORTS
+};
+
+#define _OUTPUT_PINS_ENUM_ELEMENT(index, port, bit) outpin_index_##index,
+#define OUTPUT_PINS_ENUM_ELEMENT(x) _OUTPUT_PINS_ENUM_ELEMENT x
+enum OUTPUT_PINS {
+    MAP(OUTPUT_PINS_ENUM_ELEMENT, MATRIX_OUT_PINS)
+    END_outpin_index
+};
+
+port_width_t iport_mask[NUM_OF_INPUT_PORTS];
+
+#define _INPUT_PORTS_LIST_ELEMENT(name, dev, port) \
+    [inport_index_##name] = { dev, port },
+#define INPUT_PORTS_LIST_ELEMENT(x) _INPUT_PORTS_LIST_ELEMENT x
+LOCAL_DATA
+const port_descriptor inport_list[NUM_OF_INPUT_PORTS] = {
+    INPUT_PORTS_LIST_ELEMENT((NO_PORT, NO_DEVICE, 0))
+    MAP(INPUT_PORTS_LIST_ELEMENT, MATRIX_IN_PORTS)
+};
+
+#define _OUTPUT_PORTS_LIST_ELEMENT(name, dev, port) \
+    [outport_index_##name] = { dev, port },
+#define OUTPUT_PORTS_LIST_ELEMENT(x) _OUTPUT_PORTS_LIST_ELEMENT x
+LOCAL_DATA
+const port_descriptor outport_list[NUM_OF_OUTPUT_PORTS] = {
+    OUTPUT_PORTS_LIST_ELEMENT((NO_PORT, NO_DEVICE, 0))
+#ifdef MATRIX_OUT_PORTS
+    MAP(OUTPUT_PORTS_LIST_ELEMENT, MATRIX_OUT_PORTS)
+#endif
+};
+
+#define _SELECT_OUTPUT_PIN(index, pname, bit) \
+    case outpin_index_##index: \
+        setMatrixOutput_writeLow(outport_list[outport_index_##pname].device,     \
+                                 outport_list[outport_index_##pname].port, bit); \
+    break;
+#define SELECT_OUTPUT_PIN(x) _SELECT_OUTPUT_PIN x
+LOCAL_FUNC ALWAYS_INLINE void select_output(uint8_t out_index);
+LOCAL_FUNC
+void select_output(uint8_t out_index) {
+    switch (out_index) {
+        MAP(SELECT_OUTPUT_PIN, MATRIX_OUT_PINS)
+    }
+}
+
+#define _UNSELECT_OUTPUT_PIN(index, pname, bit) \
+    case outpin_index_##index: \
+        setMatrixOutput_writeHighZ(outport_list[outport_index_##pname].device,     \
+                                   outport_list[outport_index_##pname].port, bit); \
+    break;
+#define UNSELECT_OUTPUT_PIN(x) _UNSELECT_OUTPUT_PIN x
+LOCAL_FUNC ALWAYS_INLINE void unselect_output_inline(uint8_t out_index);
+LOCAL_FUNC
+void unselect_output_inline(uint8_t out_index) {
+    switch (out_index) {
+        MAP(UNSELECT_OUTPUT_PIN, MATRIX_OUT_PINS)
+    }
+}
+
+#define _INIT_INPUT_PIN(index, pname, bit) \
+    setMatrixInputHigh(inport_list[inport_index_##pname].device,    \
+                       inport_list[inport_index_##pname].port, bit);
+#define INIT_INPUT_PIN(x) _INIT_INPUT_PIN x
+LOCAL_FUNC
+void init_input_ports(void) {
+    MAP(INIT_INPUT_PIN, MATRIX_IN_PINS)
+}
+
+#define _INIT_INPORT_MASK(index, pname, bit) \
+    iport_mask[inport_index_##pname] |= getMatrixInputMaskBit(inport_list[inport_index_##pname].device, bit);
+#define INIT_INPORT_MASK(x)  _INIT_INPORT_MASK x
+LOCAL_FUNC
+void init_inport_mask(void) {
+    for (int i = 0; i < NUM_OF_INPUT_PORTS; i++ ) {
+        iport_mask[i] = 0;
+    }
+    MAP(INIT_INPORT_MASK, MATRIX_IN_PINS)
+}
+
+#define _READ_INPUT_PORT(name, dev, port) \
+    buffer[inport_index_##name] = readMatrixPort(dev, port);
+#define READ_INPUT_PORT(x) _READ_INPUT_PORT x
+LOCAL_FUNC
+ALWAYS_INLINE void read_all_input_ports(port_width_t buffer[NUM_OF_INPUT_PORTS], bool wait_unselect);
+LOCAL_FUNC
+void read_all_input_ports(port_width_t buffer[NUM_OF_INPUT_PORTS], bool wait_unselect) {
+    READ_INPUT_PORT((NO_PORT, NO_DEVICE, 0))
+    MAP(READ_INPUT_PORT, MATRIX_IN_PORTS)
+}
+
+#define _MASK_INPUT(name, dev, port) \
+    mask |= ((~buffer[inport_index_##name]) & iport_mask[inport_index_##name]);
+#define MASK_INPUT(x) _MASK_INPUT x
+LOCAL_FUNC ALWAYS_INLINE void wait_unselect_done(void);
+LOCAL_FUNC
+void wait_unselect_done(void) {
+    port_width_t mask;
+    port_width_t buffer[NUM_OF_INPUT_PORTS];
+    do {
+        read_all_input_ports(buffer, true);
+        MATRIX_DEBUG_DELAY_END();
+        mask = 0;
+        MAP(MASK_INPUT, MATRIX_IN_PORTS);
+        MATRIX_DEBUG_DELAY_START();
+    } while (mask != 0);
+}
+
+#define _BUILD_INPUT_PORT(index, pname, bit) \
+    result |= (buffer[inport_index_##pname] & _BV(bit)) ? 0 : _BV(inpin_index_##index);
+#define BUILD_INPUT_PORT(x) _BUILD_INPUT_PORT x
+LOCAL_FUNC ALWAYS_INLINE matrix_line_t build_matrix_line(port_width_t buffer[NUM_OF_INPUT_PORTS]);
+LOCAL_FUNC
+matrix_line_t build_matrix_line(port_width_t buffer[NUM_OF_INPUT_PORTS]) {
+    matrix_line_t result = 0;
+    MAP(BUILD_INPUT_PORT, MATRIX_IN_PINS);
+    return result;
+}
+
+#define _BUILD_INPUT_PORT_DIRECT(index, pname, bit) \
+    matrix[(inpin_index_##index)/MATRIX_COLS] \
+        |= (buffer[inport_index_##pname] & _BV(bit)) ? 0 : _BV((inpin_index_##index)%MATRIX_COLS);
+#define BUILD_INPUT_PORT_DIRECT(x) _BUILD_INPUT_PORT_DIRECT x
+LOCAL_FUNC ALWAYS_INLINE void build_matrix_direct(port_width_t buffer[NUM_OF_INPUT_PORTS], matrix_line_t matrix[]);
+LOCAL_FUNC
+void build_matrix_direct(port_width_t buffer[NUM_OF_INPUT_PORTS], matrix_line_t matrix[]) {
+    MAP(BUILD_INPUT_PORT_DIRECT, MATRIX_IN_PINS);
+}
diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_extension_74hc15x.c b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_extension_74hc15x.c
new file mode 100644
index 0000000000..bca53da24c
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_extension_74hc15x.c
@@ -0,0 +1,72 @@
+/*
+Copyright 2021 mtei
+
+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/>.
+*/
+// clang-format off
+
+#if defined(MATRIX_EXTENSION_74HC157)
+#    define MATRIX_DEVICES MCU_GPIOa, MCU_GPIOb
+#    define IS_74HC15x(dev) ((dev)==MCU_GPIOa || (dev)==MCU_GPIOb)
+#    define MATRIX_EXT_74HC15x MATRIX_EXTENSION_74HC157
+#elif defined(MATRIX_EXTENSION_74HC153)
+#    define MATRIX_DEVICES MCU_GPIOa, MCU_GPIOb, MCU_GPIOc, MCU_GPIOd
+#    define IS_74HC15x(dev) ((dev)==MCU_GPIOa || (dev)==MCU_GPIOb || (dev)==MCU_GPIOc || (dev)==MCU_GPIOd)
+#    define MATRIX_EXT_74HC15x MATRIX_EXTENSION_74HC153
+#endif
+
+static const pin_t sel_pins[] = { MATRIX_EXT_74HC15x };
+
+#ifdef MATRIX_GPIO_NEED_SEPARATE_ATOMIC
+#    define setMatrixInputHigh(dev, port, bit) \
+    do {                                            \
+        if ((dev) == MCU_GPIO || IS_74HC15x(dev)) { \
+            setPortBitInputHigh_atomic(port, bit);  \
+        }
+    } while(0)
+#else
+#    define setMatrixInputHigh(dev, port, bit) \
+    do {                                            \
+        if ((dev) == MCU_GPIO || IS_74HC15x(dev)) { \
+            setPortBitInputHigh(port, bit);         \
+        }                                           \
+    } while(0)
+#endif
+
+LOCAL_FUNC ALWAYS_INLINE void select74HC15x(uint8_t devid);
+LOCAL_FUNC
+void select74HC15x(uint8_t devid) {
+    writePin(sel_pins[0], devid&1);
+#if defined(MATRIX_EXTENSION_74HC153)
+    writePin(sel_pins[1], devid&2);
+#endif
+}
+
+LOCAL_FUNC ALWAYS_INLINE port_width_t readPortMultiplexer(uint8_t devid, pin_t port);
+LOCAL_FUNC port_width_t readPortMultiplexer(uint8_t devid, pin_t port) {
+    select74HC15x(devid);
+    waitInputPinDelay();
+    return readPort(port);
+}
+
+#define readMatrixPort(dev, port) \
+    ((dev) == MCU_GPIO)? readPort(port): (IS_74HC15x(dev))? readPortMultiplexer((dev)-MCU_GPIOa, port):0
+
+#define INIT_74HC15X(x) setPinOutput(x); writePinLow(x);
+LOCAL_FUNC
+void init_74hc15x(void) {
+    MAP(INIT_74HC15X, MATRIX_EXT_74HC15x)
+}
+#define init_extension() init_74hc15x()
+
diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_extr.h b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_extr.h
new file mode 100644
index 0000000000..e0cf528919
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/matrix_extr.h
@@ -0,0 +1,36 @@
+#pragma once
+// clang-format off
+
+#define DIRECT_SWITCH 1
+#define DIODE_ROW2COL 2
+#define DIODE_COL2ROW 3
+
+#ifndef ROW2COL
+#    define COL2ROW 0
+#    define ROW2COL 1
+#endif
+
+#ifdef DIRECT_PINS
+#    define MATRIX_TYPE DIRECT_SWITCH
+#else
+#    if DIODE_DIRECTION == ROW2COL
+#        define MATRIX_TYPE DIODE_ROW2COL
+#    endif
+#    if DIODE_DIRECTION == COL2ROW
+#        define MATRIX_TYPE DIODE_COL2ROW
+#    endif
+#endif
+
+#ifndef MATRIX_TYPE
+#   error "MATRIX_TYPE could not be determined."
+#endif
+
+#if (MATRIX_ROWS <= 8)
+typedef uint8_t matrix_col_t;
+#elif (MATRIX_ROWS <= 16)
+typedef uint16_t matrix_col_t;
+#elif (MATRIX_ROWS <= 32)
+typedef uint32_t matrix_col_t;
+#else
+#    error "MATRIX_ROWS: invalid value"
+#endif
diff --git a/keyboards/handwired/symmetric70_proto/matrix_fast/readme.md b/keyboards/handwired/symmetric70_proto/matrix_fast/readme.md
new file mode 100644
index 0000000000..dc744a4c46
--- /dev/null
+++ b/keyboards/handwired/symmetric70_proto/matrix_fast/readme.md
@@ -0,0 +1,168 @@
+# Fast and extensible matrix.c
+
+This matrix.c is faster and more extensible than the standard quantum/matrix.c.
+
+* The execution speed of the `matrix_scan()` function is several times faster than quantum/matrix.c.
+* In addition to handling MCU GPIOs, it can be extended to handle I/O extenders.
+
+## ToDo list
+- [x] support Pro Micro
+- [x] support Proton-C
+- [x] support DIRECT_PINS
+- [x] support DIODE_DIRECTION == ROW2COL
+- [x] support 74HC157: quadruple 2-line to 1-line data selectors / multiplexers
+- [x] support 74HC153: dual 4-line to 1-line data selectors / multiplexers
+- [ ] support I/O expander (MCP23018)
+- [ ] support MCU & I/O expander (MCP23018) mixture like ErgoDox
+
+## Configuration
+
+This matrix.c requires a different configuration than quantum/matrix.c.
+
+### Output pins configuration
+
+The output pins is the Row pins if `DIODE_DIRECTION == COL2ROW`, and the Col pins if `DIODE_DIRECTION == ROW2COL`. When DIRECT_PINS is defined, the output pins do not need to be set.
+
+Example:
+```c
+// list of OUTPUT(row) ports
+#define MATRIX_OUT_PORTS  \
+    (Port_D, MCU_GPIO, D0), \
+    (Port_C, MCU_GPIO, C0), \
+    (Port_E, MCU_GPIO, E0), \
+    (Port_B, MCU_GPIO, B0)
+// list of OUTPUT pins
+#define MATRIX_OUT_PINS  \
+    (0, Port_D, 4), \
+    (1, Port_C, 6), \
+    (2, Port_D, 7), \
+    (3, Port_E, 6), \
+    (4, Port_B, 4), \
+    (5, Port_B, 5)
+```
+
+### Input pins configuration
+
+The input pins is the Col pins if `DIODE_DIRECTION == COL2ROW`, and the Row pins if `DIODE_DIRECTION == ROW2COL`. When DIRECT_PINS is defined, the input pin settings will enumerate the connection pins of all switches.
+
+Example:
+```c
+// list of INPUT ports
+#define MATRIX_IN_PORTS (Port_F, MCU_GPIO, F0), (Port_B, MCU_GPIO, B0)
+// list of INPUT pins
+#define MATRIX_IN_PINS \
+    (0, Port_F, 4), \
+    (1, Port_F, 5), \
+    (2, Port_F, 6), \
+    (3, Port_F, 7), \
+    (4, Port_B, 1), \
+    (5, Port_B, 3)
+```
+
+### Multiplexer Extension
+
+By defining the `MATRIX_EXTENSION_74HC157` macro or `MATRIX_EXTENSION_74HC153` macro, you can connect a multiplexer to the GPIO to extend the input pins.
+
+Example:
+```c
+#define MATRIX_EXTENSION_74HC157 B2 /* or #define MATRIX_EXTENSION_74HC153 B2, B6 */
+
+// list of OUTPUT ports
+#define MATRIX_OUT_PORTS (Port_D, MCU_GPIO, D0), (Port_C, MCU_GPIO, C0), (Port_E, MCU_GPIO, E0), (Port_B, MCU_GPIO, B0)
+// list of OUTPUT pins
+#define MATRIX_OUT_PINS  (0, Port_D, 4), (1, Port_C, 6), (2, Port_D, 7), (3, Port_E, 6), (4, Port_B, 4), (5, Port_B, 5)