diff --git a/keyboards/planck/keymaps/atreus/config.h b/keyboards/planck/keymaps/atreus/config.h
new file mode 100644
index 000000000..c83a0279d
--- /dev/null
+++ b/keyboards/planck/keymaps/atreus/config.h
@@ -0,0 +1,55 @@
+/* Copyright 2015-2017 Jack Humbert
+ *
+ * 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
+
+#ifdef AUDIO_ENABLE
+ #define STARTUP_SONG SONG(PLANCK_SOUND)
+ // #define STARTUP_SONG SONG(NO_SOUND)
+
+ #define DEFAULT_LAYER_SONGS { SONG(QWERTY_SOUND), \
+ SONG(COLEMAK_SOUND), \
+ SONG(DVORAK_SOUND) \
+ }
+#endif
+
+/*
+ * MIDI options
+ */
+
+/* Prevent use of disabled MIDI features in the keymap */
+//#define MIDI_ENABLE_STRICT 1
+
+/* enable basic MIDI features:
+ - MIDI notes can be sent when in Music mode is on
+*/
+
+#define MIDI_BASIC
+
+/* enable advanced MIDI features:
+ - MIDI notes can be added to the keymap
+ - Octave shift and transpose
+ - Virtual sustain, portamento, and modulation wheel
+ - etc.
+*/
+//#define MIDI_ADVANCED
+
+/* override number of MIDI tone keycodes (each octave adds 12 keycodes and allocates 12 bytes) */
+//#define MIDI_TONE_KEYCODE_OCTAVES 2
+
+// Most tactile encoders have detents every 4 stages
+#define ENCODER_RESOLUTION 4
+
diff --git a/keyboards/planck/keymaps/atreus/keymap.c b/keyboards/planck/keymaps/atreus/keymap.c
new file mode 100644
index 000000000..b78a7017e
--- /dev/null
+++ b/keyboards/planck/keymaps/atreus/keymap.c
@@ -0,0 +1,239 @@
+/* Copyright 2015-2017 Jack Humbert
+ *
+ * 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 QMK_KEYBOARD_H
+#include "muse.h"
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+/* Default layer
+ * ,-----------------------------------------------------------------------------------.
+ * | 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 | , | . | / |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Esc | Tab | GUI | Shift| Bksp | Ctrl | Alt |Space | Fun | - | ' |Enter |
+ * `-----------------------------------------------------------------------------------'
+ */
+[0] = LAYOUT_ortho_4x12(
+ KC_Q, KC_W, KC_E, KC_R, KC_T, KC_NO, KC_NO, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_A, KC_S, KC_D, KC_F, KC_G, KC_NO, KC_NO, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_GRV, KC_BSLS, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_ESC, KC_TAB, KC_LGUI, KC_LSFT, KC_BSPC, KC_LCTL, KC_LALT, KC_SPC, MO(1), KC_MINS, KC_QUOT, KC_ENT),
+/* Function layer
+ * ,-----------------------------------------------------------------------------------.
+ * | ! | @ | Up | $ | % | | | PgUp | 7 | 8 | 9 | Bksp |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | ( | Left | Down |Right | ) | | | PgDn | 4 | 5 | 6 | |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | [ | ] | # | { | } | ^ | & | * | 1 | 2 | 3 | + |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Upper| Ins | | | | | | | | . | 0 | = |
+ * `-----------------------------------------------------------------------------------'
+ */
+[1] = LAYOUT_ortho_4x12(
+ KC_EXLM, KC_AT, KC_UP, KC_DLR, KC_PERC, KC_NO, KC_NO, KC_PGUP, KC_7, KC_8, KC_9, KC_BSPC, KC_LPRN, KC_LEFT, KC_DOWN, KC_RGHT, KC_RPRN, KC_NO, KC_NO, KC_PGDN, KC_4, KC_5, KC_6, KC_NO, KC_LBRC, KC_RBRC, KC_HASH, KC_LCBR, KC_RCBR, KC_CIRC, KC_AMPR, KC_ASTR, KC_1, KC_2, KC_3, KC_PLUS, TG(2), KC_INS, KC_LGUI, KC_LSFT, KC_DEL, KC_LCTL, KC_LALT, KC_SPC, KC_TRNS, KC_DOT, KC_0, KC_EQL),
+/* Upper layer
+ * ,-----------------------------------------------------------------------------------.
+ * | Ins | Home | | End | PgUp | | | Up | F7 | F8 | F9 | F10 |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | Del | | | | PgDn | | | Down | F4 | F5 | F6 | F11 |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | Vol+ | | | | | | | F1 | F2 | F3 | F12 |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * | | Vol- | | | | | | | |PrtSc |ScrLk | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[2] = LAYOUT_ortho_4x12(
+ KC_INS, KC_HOME, KC_UP, KC_END, KC_PGUP, KC_NO, KC_NO, KC_UP, KC_F7, KC_F8, KC_F9, KC_F10, KC_DEL, KC_LEFT, KC_DOWN, KC_RGHT, KC_PGDN, KC_NO, KC_NO, KC_DOWN, KC_F4, KC_F5, KC_F6, KC_F11, KC_NO, KC_VOLU, KC_NO, KC_NO, KC_NO, KC_NO, KC_NO, KC_NO, KC_F1, KC_F2, KC_F3, KC_F12, KC_NO, KC_VOLD, KC_NO, KC_NO, KC_NO, KC_NO, KC_NO, KC_NO, TO(0), KC_PSCR, KC_SLCK, KC_MPLY)
+};
+
+#ifdef AUDIO_ENABLE
+ float plover_song[][2] = SONG(PLOVER_SOUND);
+ float plover_gb_song[][2] = SONG(PLOVER_GOODBYE_SOUND);
+#endif
+
+layer_state_t layer_state_set_user(layer_state_t state) {
+ return update_tri_layer_state(state, _LOWER, _RAISE, _ADJUST);
+}
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+ switch (keycode) {
+ case QWERTY:
+ if (record->event.pressed) {
+ print("mode just switched to qwerty and this is a huge string\n");
+ set_single_persistent_default_layer(_QWERTY);
+ }
+ return false;
+ break;
+ case COLEMAK:
+ if (record->event.pressed) {
+ set_single_persistent_default_layer(_COLEMAK);
+ }
+ return false;
+ break;
+ case DVORAK:
+ if (record->event.pressed) {
+ set_single_persistent_default_layer(_DVORAK);
+ }
+ return false;
+ break;
+ case BACKLIT:
+ if (record->event.pressed) {
+ register_code(KC_RSFT);
+ #ifdef BACKLIGHT_ENABLE
+ backlight_step();
+ #endif
+ #ifdef KEYBOARD_planck_rev5
+ writePinLow(E6);
+ #endif
+ } else {
+ unregister_code(KC_RSFT);
+ #ifdef KEYBOARD_planck_rev5
+ writePinHigh(E6);
+ #endif
+ }
+ return false;
+ break;
+ case PLOVER:
+ if (record->event.pressed) {
+ #ifdef AUDIO_ENABLE
+ stop_all_notes();
+ PLAY_SONG(plover_song);
+ #endif
+ layer_off(_RAISE);
+ layer_off(_LOWER);
+ layer_off(_ADJUST);
+ layer_on(_PLOVER);
+ if (!eeconfig_is_enabled()) {
+ eeconfig_init();
+ }
+ keymap_config.raw = eeconfig_read_keymap();
+ keymap_config.nkro = 1;
+ eeconfig_update_keymap(keymap_config.raw);
+ }
+ return false;
+ break;
+ case EXT_PLV:
+ if (record->event.pressed) {
+ #ifdef AUDIO_ENABLE
+ PLAY_SONG(plover_gb_song);
+ #endif
+ layer_off(_PLOVER);
+ }
+ return false;
+ break;
+ }
+ return true;
+}
+
+bool muse_mode = false;
+uint8_t last_muse_note = 0;
+uint16_t muse_counter = 0;
+uint8_t muse_offset = 70;
+uint16_t muse_tempo = 50;
+
+void encoder_update(bool clockwise) {
+ if (muse_mode) {
+ if (IS_LAYER_ON(_RAISE)) {
+ if (clockwise) {
+ muse_offset++;
+ } else {
+ muse_offset--;
+ }
+ } else {
+ if (clockwise) {
+ muse_tempo+=1;
+ } else {
+ muse_tempo-=1;
+ }
+ }
+ } else {
+ if (clockwise) {
+ #ifdef MOUSEKEY_ENABLE
+ tap_code(KC_MS_WH_DOWN);
+ #else
+ tap_code(KC_PGDN);
+ #endif
+ } else {
+ #ifdef MOUSEKEY_ENABLE
+ tap_code(KC_MS_WH_UP);
+ #else
+ tap_code(KC_PGUP);
+ #endif
+ }
+ }
+}
+
+void dip_switch_update_user(uint8_t index, bool active) {
+ switch (index) {
+ case 0: {
+#ifdef AUDIO_ENABLE
+ static bool play_sound = false;
+#endif
+ if (active) {
+#ifdef AUDIO_ENABLE
+ if (play_sound) { PLAY_SONG(plover_song); }
+#endif
+ layer_on(_ADJUST);
+ } else {
+#ifdef AUDIO_ENABLE
+ if (play_sound) { PLAY_SONG(plover_gb_song); }
+#endif
+ layer_off(_ADJUST);
+ }
+#ifdef AUDIO_ENABLE
+ play_sound = true;
+#endif
+ break;
+ }
+ case 1:
+ if (active) {
+ muse_mode = true;
+ } else {
+ muse_mode = false;
+ }
+ }
+}
+
+void matrix_scan_user(void) {
+#ifdef AUDIO_ENABLE
+ if (muse_mode) {
+ if (muse_counter == 0) {
+ uint8_t muse_note = muse_offset + SCALE[muse_clock_pulse()];
+ if (muse_note != last_muse_note) {
+ stop_note(compute_freq_for_midi_note(last_muse_note));
+ play_note(compute_freq_for_midi_note(muse_note), 0xF);
+ last_muse_note = muse_note;
+ }
+ }
+ muse_counter = (muse_counter + 1) % muse_tempo;
+ } else {
+ if (muse_counter) {
+ stop_all_notes();
+ muse_counter = 0;
+ }
+ }
+#endif
+}
+
+bool music_mask_user(uint16_t keycode) {
+ switch (keycode) {
+ case RAISE:
+ case LOWER:
+ return false;
+ default:
+ return true;
+ }
+}
diff --git a/keyboards/planck/keymaps/atreus/readme.md b/keyboards/planck/keymaps/atreus/readme.md
new file mode 100644
index 000000000..81940642c
--- /dev/null
+++ b/keyboards/planck/keymaps/atreus/readme.md
@@ -0,0 +1,9 @@
+
+
+# Keyboardio Atreus layout for Planck
+
+This is the same layout as the new Atreus from Keyboardio (the one with 44 keys, so not the atreus v1).
+There are 4 unused keys in the center as the Planck has 48 keys.
+It is mostly for people with a Planck to try this new layout before buying.
+
+More details here: https://shop.keyboard.io/products/keyboardio-atreus
diff --git a/keyboards/planck/keymaps/atreus/rules.mk b/keyboards/planck/keymaps/atreus/rules.mk
new file mode 100644
index 000000000..dcf16bef3
--- /dev/null
+++ b/keyboards/planck/keymaps/atreus/rules.mk
@@ -0,0 +1 @@
+SRC += muse.c