Merge pull request #134 from xauser/master

Support for Lightpad keypad

9 files changed, 686 insertions, 0 deletions

diff --git a/keyboard/lightpad/Makefile.lufa b/keyboard/lightpad/Makefile.lufa
new file mode 100644
index 0000000000..7bce7ebffc
--- /dev/null
+++ b/keyboard/lightpad/Makefile.lufa
@@ -0,0 +1,117 @@
+#----------------------------------------------------------------------------
+# On command line:
+#
+# make all = Make software.
+#
+# make clean = Clean out built project files.
+#
+# make coff = Convert ELF to AVR COFF.
+#
+# make extcoff = Convert ELF to AVR Extended COFF.
+#
+# make program = Download the hex file to the device.
+#                Please customize your programmer settings(PROGRAM_CMD)
+#
+# make teensy = Download the hex file to the device, using teensy_loader_cli.
+#               (must have teensy_loader_cli installed).
+#
+# make dfu = Download the hex file to the device, using dfu-programmer (must
+#            have dfu-programmer installed).
+#
+# make flip = Download the hex file to the device, using Atmel FLIP (must
+#             have Atmel FLIP installed).
+#
+# make dfu-ee = Download the eeprom file to the device, using dfu-programmer
+#               (must have dfu-programmer installed).
+#
+# make flip-ee = Download the eeprom file to the device, using Atmel FLIP
+#                (must have Atmel FLIP installed).
+#
+# make debug = Start either simulavr or avarice as specified for debugging, 
+#              with avr-gdb or avr-insight as the front end for debugging.
+#
+# make filename.s = Just compile filename.c into the assembler code only.
+#
+# make filename.i = Create a preprocessed source file for use in submitting
+#                   bug reports to the GCC project.
+#
+# To rebuild project do "make clean" then "make all".
+#----------------------------------------------------------------------------
+
+# Target file name (without extension).
+TARGET = lightpad_lufa
+
+# Directory common source filess exist
+TOP_DIR = ../..
+
+# Directory keyboard dependent files exist
+TARGET_DIR = .
+
+# List C source files here. (C dependencies are automatically generated.)
+SRC =	keymap.c \
+	matrix.c \
+	led.c \
+	backlight.c
+
+CONFIG_H = config.h
+
+# MCU name
+MCU = atmega32u4
+
+# Processor frequency.
+#     This will define a symbol, F_CPU, in all source code files equal to the
+#     processor frequency in Hz. You can then use this symbol in your source code to
+#     calculate timings. Do NOT tack on a 'UL' at the end, this will be done
+#     automatically to create a 32-bit value in your source code.
+#
+#     This will be an integer division of F_USB below, as it is sourced by
+#     F_USB after it has run through any CPU prescalers. Note that this value
+#     does not *change* the processor frequency - it should merely be updated to
+#     reflect the processor speed set externally so that the code can use accurate
+#     software delays.
+F_CPU = 8000000
+
+#
+# LUFA specific
+#
+# Target architecture (see library "Board Types" documentation).
+ARCH = AVR8
+
+# Input clock frequency.
+#     This will define a symbol, F_USB, in all source code files equal to the
+#     input clock frequency (before any prescaling is performed) in Hz. This value may
+#     differ from F_CPU if prescaling is used on the latter, and is required as the
+#     raw input clock is fed directly to the PLL sections of the AVR for high speed
+#     clock generation for the USB and other AVR subsections. Do NOT tack on a 'UL'
+#     at the end, this will be done automatically to create a 32-bit value in your
+#     source code.
+#
+#     If no clock division is performed on the input clock inside the AVR (via the
+#     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
+F_USB = $(F_CPU)
+
+# Build Options
+#   comment out to disable the options.
+#
+BOOTMAGIC_ENABLE = yes	# Virtual DIP switch configuration(+1000)
+#MOUSEKEY_ENABLE = yes	# Mouse keys(+4700)
+EXTRAKEY_ENABLE = yes	# Audio control and System control(+450)
+#CONSOLE_ENABLE = yes	# Console for debug(+400)
+#COMMAND_ENABLE = yes    # Commands for debug and configuration
+#SLEEP_LED_ENABLE = yes  # Breathing sleep LED during USB suspend
+#NKRO_ENABLE = yes	# USB Nkey Rollover - not yet supported in LUFA
+BACKLIGHT_ENABLE = yes  # Enable keyboard backlight functionality
+
+# Boot Section Size in bytes
+#   Teensy halfKay   512
+#   Atmel DFU loader 4096
+#   LUFA bootloader  4096
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
+
+# Search Path
+VPATH += $(TARGET_DIR)
+VPATH += $(TOP_DIR)
+
+include $(TOP_DIR)/protocol/lufa.mk
+include $(TOP_DIR)/common.mk
+include $(TOP_DIR)/rules.mk
diff --git a/keyboard/lightpad/README.md b/keyboard/lightpad/README.md
new file mode 100644
index 0000000000..b21cccc6a2
--- /dev/null
+++ b/keyboard/lightpad/README.md
@@ -0,0 +1,24 @@
+Lightpad keypad firmware
+======================
+Korean custom keypad designed by Duck.
+
+*Note that this is not the official firmware*
+
+
+Supported models
+----------------
+All pcb options are supported.
+
+
+Build
+-----
+Move to this directory then just run `make` like:
+
+    $ make -f Makefile.lufa
+
+
+Bootloader
+---------
+The PCB is hardwired to run the bootloader if the key at the `top left` position is held down when connecting the keyboard.
+
+It is still possible to use Boot Magic and Command to access the bootloader though.
diff --git a/keyboard/lightpad/backlight.c b/keyboard/lightpad/backlight.c
new file mode 100644
index 0000000000..693c566fc5
--- /dev/null
+++ b/keyboard/lightpad/backlight.c
@@ -0,0 +1,129 @@
+/*
+Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
+
+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 <avr/io.h>
+#include "backlight.h"
+
+/* Backlight pin configuration
+ *
+ * FN1       PB0 (low)
+ * FN2       PB5 (low)
+ * FN3       PB4 (low)
+ * FN4       PD7 (low)
+ * REAR      PD6 (high)
+ * NUMPAD    PB2 (high)
+ * NUMLOCK   PB1 (low)
+ */
+void backlight_init_ports() {
+    DDRB |= (1<<0) | (1<<1) | (1<<2) | (1<<4) | (1<<5);
+    DDRD |= (1<<6) | (1<<7);
+
+    backlight_disable_numlock();
+}
+
+void backlight_set(uint8_t level) {
+    (level & BACKLIGHT_FN1) ? backlight_enable_fn1() : backlight_disable_fn1();
+    (level & BACKLIGHT_FN2) ? backlight_enable_fn2() : backlight_disable_fn2();
+    (level & BACKLIGHT_FN3) ? backlight_enable_fn3() : backlight_disable_fn3();
+    (level & BACKLIGHT_FN4) ? backlight_enable_fn4() : backlight_disable_fn4();
+    (level & BACKLIGHT_NUMPAD) ? backlight_enable_numpad() : backlight_disable_numpad();
+    (level & BACKLIGHT_REAR) ? backlight_enable_rear() : backlight_disable_rear();
+}
+
+void backlight_enable_fn1() {
+    PORTB &= ~(1<<0);
+}
+
+void backlight_disable_fn1() {
+    PORTB |= (1<<0);
+}
+
+void backlight_invert_fn1() {
+    PORTB ^= (1<<0);
+}
+
+void backlight_enable_fn2() {
+    PORTB &= ~(1<<5);
+}
+
+void backlight_disable_fn2() {
+    PORTB |= (1<<5);
+}
+
+void backlight_invert_fn2() {
+    PORTB ^= (1<<5);
+}
+
+void backlight_enable_fn3() {
+    PORTB &= ~(1<<4);
+}
+
+void backlight_disable_fn3() {
+    PORTB |= (1<<4);
+}
+
+void backlight_invert_fn3() {
+    PORTB ^= (1<<4);
+}
+
+void backlight_enable_fn4() {
+    PORTD &= ~(1<<7);
+}
+
+void backlight_disable_fn4() {
+    PORTD |= (1<<7);
+}
+
+void backlight_invert_fn4() {
+    PORTD ^= (1<<7);
+}
+
+void backlight_enable_numpad() {
+    PORTB |= (1<<2);
+}
+
+void backlight_disable_numpad() {
+    PORTB &= ~(1<<2);
+}
+
+void backlight_invert_numpad() {
+    PORTB ^= (1<<2);
+}
+
+void backlight_enable_numlock() {
+    PORTB &= ~(1<<1);
+}
+
+void backlight_disable_numlock() {
+    PORTB |= (1<<1);
+}
+
+void backlight_invert_numlock() {
+    PORTB ^= (1<<1);
+}
+
+void backlight_enable_rear() {
+    PORTD |= (1<<6);
+}
+
+void backlight_disable_rear() {
+    PORTD &= ~(1<<6);
+}
+
+void backlight_invert_rear() {
+    PORTD ^= (1<<6);
+}
diff --git a/keyboard/lightpad/backlight.h b/keyboard/lightpad/backlight.h
new file mode 100644
index 0000000000..3b3cfd9aea
--- /dev/null
+++ b/keyboard/lightpad/backlight.h
@@ -0,0 +1,39 @@
+
+enum backlight_level {
+    BACKLIGHT_FN1    = 0b0000001,
+    BACKLIGHT_FN2    = 0b0000010,
+    BACKLIGHT_FN3    = 0b0000100,
+    BACKLIGHT_FN4    = 0b0001000,
+    BACKLIGHT_NUMPAD = 0b0010000,
+    BACKLIGHT_REAR   = 0b0100000,
+};
+
+void backlight_init_ports(void);
+
+void backlight_invert_fn1(void);
+void backlight_enable_fn1(void);
+void backlight_disable_fn1(void);
+
+void backlight_invert_fn2(void);
+void backlight_enable_fn2(void);
+void backlight_disable_fn2(void);
+
+void backlight_invert_fn3(void);
+void backlight_enable_fn3(void);
+void backlight_disable_fn3(void);
+
+void backlight_invert_fn4(void);
+void backlight_enable_fn4(void);
+void backlight_disable_fn4(void);
+
+void backlight_invert_numlock(void);
+void backlight_enable_numlock(void);
+void backlight_disable_numlock(void);
+
+void backlight_enable_numpad(void);
+void backlight_disable_numpad(void);
+void backlight_invert_numpad(void);
+
+void backlight_enable_rear(void);
+void backlight_disable_rear(void);
+void backlight_invert_rear(void);
diff --git a/keyboard/lightpad/config.h b/keyboard/lightpad/config.h
new file mode 100644
index 0000000000..7f5a596c0c
--- /dev/null
+++ b/keyboard/lightpad/config.h
@@ -0,0 +1,46 @@
+/*
+Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
+
+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/>.
+*/
+
+#ifndef CONFIG_H
+#define CONFIG_H
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID       0xFEED
+#define PRODUCT_ID      0x6050
+#define DEVICE_VER      0x0104
+#define MANUFACTURER    Duck
+#define PRODUCT         Lightpad
+
+/* message strings */
+#define DESCRIPTION     t.m.k. keyboard firmware for Lightpad
+
+/* matrix size */
+#define MATRIX_ROWS 6
+#define MATRIX_COLS 4
+
+/* number of backlight levels */
+#define BACKLIGHT_LEVELS 1
+
+/* Set 0 if need no debouncing */
+#define DEBOUNCE    5
+
+/* key combination for command */
+#define IS_COMMAND() ( \
+    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
+)
+
+#endif
diff --git a/keyboard/lightpad/keymap.c b/keyboard/lightpad/keymap.c
new file mode 100644
index 0000000000..6d078230bb
--- /dev/null
+++ b/keyboard/lightpad/keymap.c
@@ -0,0 +1,73 @@
+/*
+Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
+
+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 <stdint.h>
+#include <stdbool.h>
+#include <avr/pgmspace.h>
+#include "keycode.h"
+#include "action.h"
+#include "action_macro.h"
+#include "report.h"
+#include "host.h"
+#include "debug.h"
+#include "keymap.h"
+
+/* Map physical keyboard layout to matrix array */
+#define KEYMAP( \
+            K5A, K5B, K5C, K5D, \
+            K4A, K4B, K4C, K4D, \
+            K3A, K3B, K3C, K3D, \
+            K2A, K2B, K2C,      \
+            K1A, K1B, K1C, K1D, \
+            K0A, K0B, K0C       \
+) { \
+/*             0         1         2         3    */ \
+/* 5 */   { KC_##K5A, KC_##K5B, KC_##K5C, KC_##K5D}, \
+/* 4 */   { KC_##K4A, KC_##K4B, KC_##K4C, KC_##K4D}, \
+/* 3 */   { KC_##K3A, KC_##K3B, KC_##K3C, KC_##K3D}, \
+/* 2 */   { KC_##K2A, KC_##K2B, KC_##K2C, KC_NO},    \
+/* 1 */   { KC_##K1A, KC_##K1B, KC_##K1C, KC_##K1D}, \
+/* 0 */   { KC_##K0A, KC_##K0B, KC_##K0C, KC_NO,  }  \
+}
+
+#include "keymap_lightpad.h"
+
+#define KEYMAPS_SIZE    (sizeof(keymaps) / sizeof(keymaps[0]))
+#define FN_ACTIONS_SIZE (sizeof(fn_actions) / sizeof(fn_actions[0]))
+
+/* translates key to keycode */
+uint8_t keymap_key_to_keycode(uint8_t layer, key_t key)
+{
+    if (layer < KEYMAPS_SIZE) {
+        return pgm_read_byte(&keymaps[(layer)][(key.row)][(key.col)]);
+    } else {
+        // fall back to layer 0
+        return pgm_read_byte(&keymaps[0][(key.row)][(key.col)]);
+    }
+}
+
+/* translates Fn keycode to action */
+action_t keymap_fn_to_action(uint8_t keycode)
+{
+    action_t action;
+    if (FN_INDEX(keycode) < FN_ACTIONS_SIZE) {
+        action.code = pgm_read_word(&fn_actions[FN_INDEX(keycode)]);
+    } else {
+        action.code = ACTION_NO;
+    }
+    return action;
+}
diff --git a/keyboard/lightpad/keymap_lightpad.h b/keyboard/lightpad/keymap_lightpad.h
new file mode 100644
index 0000000000..9333964e39
--- /dev/null
+++ b/keyboard/lightpad/keymap_lightpad.h
@@ -0,0 +1,29 @@
+#include "backlight.h"
+
+static const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    KEYMAP(\
+        FN0, F1,  DEL, BSPC, \
+        NLCK,PSLS,PAST,PMNS, \
+        P7,  P8,  P9,  PPLS, \
+        P4,  P5,  P6,        \
+        P1,  P2,  P3,  PENT, \
+        P0,  NO,  PDOT),     \
+    KEYMAP(\
+        TRNS,PGDN,PGUP,MUTE, \
+        MSEL,MPRV,MNXT,VOLD, \
+        P7,  P8,  P9,  VOLU, \
+        FN4, FN5, FN6,       \
+        FN1, FN2, FN3, MPLY, \
+        FN7, NO,  MSTP)
+};
+
+static const uint16_t PROGMEM fn_actions[] = {
+    [0] = ACTION_LAYER_MOMENTARY(1),
+    [1] = ACTION_BACKLIGHT_LEVEL(BACKLIGHT_FN1),
+    [2] = ACTION_BACKLIGHT_LEVEL(BACKLIGHT_FN2),
+    [3] = ACTION_BACKLIGHT_LEVEL(BACKLIGHT_FN3),
+    [4] = ACTION_BACKLIGHT_LEVEL(BACKLIGHT_FN4),
+    [5] = ACTION_BACKLIGHT_LEVEL(BACKLIGHT_NUMPAD),
+    [6] = ACTION_BACKLIGHT_LEVEL(BACKLIGHT_REAR),
+    [7] = ACTION_BACKLIGHT_TOGGLE()
+};
diff --git a/keyboard/lightpad/led.c b/keyboard/lightpad/led.c
new file mode 100644
index 0000000000..ebfac3af89
--- /dev/null
+++ b/keyboard/lightpad/led.c
@@ -0,0 +1,24 @@
+/*
+Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
+
+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 <avr/io.h>
+#include "stdint.h"
+#include "led.h"
+
+void led_set(uint8_t usb_led) {
+    (usb_led & (1<<USB_LED_NUM_LOCK)) ? backlight_enable_numlock() : backlight_disable_numlock();
+}
diff --git a/keyboard/lightpad/matrix.c b/keyboard/lightpad/matrix.c
new file mode 100644
index 0000000000..87d338395b
--- /dev/null
+++ b/keyboard/lightpad/matrix.c
@@ -0,0 +1,205 @@
+/*
+Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
+
+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 <stdint.h>
+#include <stdbool.h>
+#include <avr/io.h>
+#include <util/delay.h>
+#include "print.h"
+#include "debug.h"
+#include "util.h"
+#include "matrix.h"
+#include "eeconfig.h"
+#include "action_layer.h"
+#include "backlight.h"
+
+#ifndef DEBOUNCE
+#   define DEBOUNCE 0
+#endif
+static uint8_t debouncing = DEBOUNCE;
+
+static matrix_row_t matrix[MATRIX_ROWS];
+static matrix_row_t matrix_debouncing[MATRIX_ROWS];
+
+static uint8_t read_rows(void);
+static uint8_t read_fwkey(void);
+static void init_rows(void);
+static void unselect_cols(void);
+static void select_col(uint8_t col);
+
+inline
+uint8_t matrix_rows(void)
+{
+    return MATRIX_ROWS;
+}
+
+inline
+uint8_t matrix_cols(void)
+{
+    return MATRIX_COLS;
+}
+
+void misc_init(void) {
+}
+
+void matrix_init(void)
+{
+    backlight_init_ports();
+    unselect_cols();
+    init_rows();
+    for (uint8_t i=0; i < MATRIX_ROWS; i++)  {
+        matrix[i] = 0;
+        matrix_debouncing[i] = 0;
+    }
+}
+
+uint8_t matrix_scan(void)
+{
+    for (uint8_t col = 0; col < MATRIX_COLS; col++) {
+        select_col(col);
+        _delay_us(3);
+        uint8_t rows = read_rows();
+        // Use the otherwise unused col: 0 row: 0 for firmware key
+        if(col == 0) {
+            rows |= read_fwkey();
+        }
+        for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+            bool prev_bit = matrix_debouncing[row] & ((matrix_row_t)1<<col);
+            bool curr_bit = rows & (1<<row);
+            if (prev_bit != curr_bit) {
+                matrix_debouncing[row] ^= ((matrix_row_t)1<<col);
+                if (debouncing) {
+                    dprint("bounce!: "); dprintf("%02X", debouncing); dprintln();
+                }
+                debouncing = DEBOUNCE;
+            }
+        }
+        unselect_cols();
+    }
+
+    if (debouncing) {
+        if (--debouncing) {
+            _delay_ms(1);
+        } else {
+            for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+                matrix[i] = matrix_debouncing[i];
+            }
+        }
+    }
+
+    return 1;
+}
+
+bool matrix_is_modified(void)
+{
+    if (debouncing) return false;
+    return true;
+}
+
+inline
+bool matrix_is_on(uint8_t row, uint8_t col)
+{
+    return (matrix[row] & ((matrix_row_t)1<<col));
+}
+
+inline
+matrix_row_t matrix_get_row(uint8_t row)
+{
+    return matrix[row];
+}
+
+void matrix_print(void)
+{
+    print("\nr/c 0123456789ABCDEF\n");
+    for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
+        xprintf("%02X: %032lb\n", row, bitrev32(matrix_get_row(row)));
+    }
+}
+
+uint8_t matrix_key_count(void)
+{
+    uint8_t count = 0;
+    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
+        count += bitpop32(matrix[i]);
+    }
+    return count;
+}
+
+/* Row configuration
+ *
+ * row: 0    1    2    3    4    5
+ * pin: PD0  PD1  PD2  PD3  PD5  PB7
+ *
+ * Firmware uses pin PE2
+ */
+static void init_rows(void)
+{
+    DDRD  &= ~0b00101111;
+    PORTD |=  0b00101111;
+
+    DDRB  &= ~0b10000000;
+    PORTB |=  0b10000000;
+
+    DDRE  &= ~0b00000100;
+    PORTE |=  0b00000100;
+}
+
+static uint8_t read_rows(void)
+{
+    return (PIND&(1<<0) ? (1<<0) : 0) |
+           (PIND&(1<<1) ? (1<<1) : 0) |
+           (PIND&(1<<2) ? (1<<2) : 0) |
+           (PIND&(1<<3) ? (1<<3) : 0) |
+           (PIND&(1<<5) ? (1<<4) : 0) |
+           (PINB&(1<<7) ? (1<<5) : 0);
+}
+
+static uint8_t read_fwkey(void)
+{
+    return PINE&(1<<2) ? 0 : (1<<0);
+}
+
+/* Column configuration
+ *
+ * col: 0    1    2    3
+ * pin: PF0  PF1  PC7  PC6
+ */
+static void unselect_cols(void)
+{
+    DDRF |=   0b00000011;
+    PORTF &= ~0b00000011;
+    DDRC |=   0b11000000;
+    PORTC &= ~0b11000000;
+}
+
+static void select_col(uint8_t col)
+{
+    switch (col) {
+        case 0:
+            PORTF |= (1<<0);
+            break;
+        case 1:
+            PORTF |= (1<<1);
+            break;
+        case 2:
+            PORTC |= (1<<7);
+            break;
+        case 3:
+            PORTC |= (1<<6);
+            break;
+    }
+}