Add SSD1306 OLED display support to TKC1800 (#2293)

* Add support for SSD1306 OLED display

* Correct keymap

Had tilde on keymap instead of grave, corrected.

* Winkeyless keymap

keyboards/tkc1800/i2c.c

@@ -0,0 +1,166 @@
+#include <util/twi.h>
+#include <avr/io.h>
+#include <stdlib.h>
+#include <avr/interrupt.h>
+#include <util/twi.h>
+#include <stdbool.h>
+#include "i2c.h"
+
+#ifdef USE_I2C
+
+// Limits the amount of we wait for any one i2c transaction.
+// Since were running SCL line 100kHz (=> 10μs/bit), and each transactions is
+// 9 bits, a single transaction will take around 90μs to complete.
+//
+// (F_CPU/SCL_CLOCK)  =>  # of μC cycles to transfer a bit
+// poll loop takes at least 8 clock cycles to execute
+#define I2C_LOOP_TIMEOUT (9+1)*(F_CPU/SCL_CLOCK)/8
+
+#define BUFFER_POS_INC() (slave_buffer_pos = (slave_buffer_pos+1)%SLAVE_BUFFER_SIZE)
+
+volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
+
+static volatile uint8_t slave_buffer_pos;
+static volatile bool slave_has_register_set = false;
+
+// Wait for an i2c operation to finish
+inline static
+void i2c_delay(void) {
+  uint16_t lim = 0;
+  while(!(TWCR & (1<<TWINT)) && lim < I2C_LOOP_TIMEOUT)
+    lim++;
+
+  // easier way, but will wait slightly longer
+  // _delay_us(100);
+}
+
+// Setup twi to run at 100kHz
+void i2c_master_init(void) {
+  // no prescaler
+  TWSR = 0;
+  // Set TWI clock frequency to SCL_CLOCK. Need TWBR>10.
+  // Check datasheets for more info.
+  TWBR = ((F_CPU/SCL_CLOCK)-16)/2;
+}
+
+// Start a transaction with the given i2c slave address. The direction of the
+// transfer is set with I2C_READ and I2C_WRITE.
+// returns: 0 => success
+//          1 => error
+uint8_t i2c_master_start(uint8_t address) {
+  TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
+
+  i2c_delay();
+
+  // check that we started successfully
+  if ( (TW_STATUS != TW_START) && (TW_STATUS != TW_REP_START))
+    return 1;
+
+  // send device address
+  TWDR = address;
+  TWCR = (1<<TWINT) | (1<<TWEN);
+
+  i2c_delay();
+
+  if ( (TW_STATUS != TW_MT_SLA_ACK) && (TW_STATUS != TW_MR_SLA_ACK) )
+    return 1; // slave did not acknowledge
+  else
+    return 0; // success
+}
+
+
+// Finish the i2c transaction.
+void i2c_master_stop(void) {
+  TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
+
+  uint16_t lim = 0;
+  while(!(TWCR & (1<<TWSTO)) && lim < I2C_LOOP_TIMEOUT)
+    lim++;
+}
+
+// Write one byte to the i2c slave.
+// returns 0 => slave ACK
+//         1 => slave NACK
+uint8_t i2c_master_write(uint8_t data) {
+  TWDR = data;
+  TWCR = (1<<TWINT) | (1<<TWEN);
+
+  i2c_delay();
+
+  // check if the slave acknowledged us
+  return (TW_STATUS == TW_MT_DATA_ACK) ? 0 : 1;
+}
+
+// Read one byte from the i2c slave. If ack=1 the slave is acknowledged,
+// if ack=0 the acknowledge bit is not set.
+// returns: byte read from i2c device
+uint8_t i2c_master_read(int ack) {
+  TWCR = (1<<TWINT) | (1<<TWEN) | (ack<<TWEA);
+
+  i2c_delay();
+  return TWDR;
+}
+
+void i2c_reset_state(void) {
+  TWCR = 0;
+}
+
+void i2c_slave_init(uint8_t address) {
+  TWAR = address << 0; // slave i2c address
+  // TWEN  - twi enable
+  // TWEA  - enable address acknowledgement
+  // TWINT - twi interrupt flag
+  // TWIE  - enable the twi interrupt
+  TWCR = (1<<TWIE) | (1<<TWEA) | (1<<TWINT) | (1<<TWEN);
+}
+
+ISR(TWI_vect);
+
+ISR(TWI_vect) {
+  uint8_t ack = 1;
+  switch(TW_STATUS) {
+    case TW_SR_SLA_ACK:
+      // this device has been addressed as a slave receiver
+      slave_has_register_set = false;
+      break;
+
+    case TW_SR_DATA_ACK:
+      // this device has received data as a slave receiver
+      // The first byte that we receive in this transaction sets the location
+      // of the read/write location of the slaves memory that it exposes over
+      // i2c.  After that, bytes will be written at slave_buffer_pos, incrementing
+      // slave_buffer_pos after each write.
+      if(!slave_has_register_set) {
+        slave_buffer_pos = TWDR;
+        // don't acknowledge the master if this memory loctaion is out of bounds
+        if ( slave_buffer_pos >= SLAVE_BUFFER_SIZE ) {
+          ack = 0;
+          slave_buffer_pos = 0;
+        }
+        slave_has_register_set = true;
+      } else {
+        i2c_slave_buffer[slave_buffer_pos] = TWDR;
+        BUFFER_POS_INC();
+      }
+      break;
+
+    case TW_ST_SLA_ACK:
+    case TW_ST_DATA_ACK:
+      // master has addressed this device as a slave transmitter and is
+      // requesting data.
+      TWDR = i2c_slave_buffer[slave_buffer_pos];
+      BUFFER_POS_INC();
+      break;
+
+    case TW_BUS_ERROR: // something went wrong, reset twi state
+      TWCR = 0;
+    default:
+      break;
+  }
+  // Reset everything, so we are ready for the next TWI interrupt
+  TWCR |= (1<<TWIE) | (1<<TWINT) | (ack<<TWEA) | (1<<TWEN);
+}
+
+
+
+#endif

keyboards/tkc1800/i2c.h

@@ -0,0 +1,49 @@
+#ifndef I2C_H
+#define I2C_H
+
+#include <stdint.h>
+
+#ifndef F_CPU
+#define F_CPU 16000000UL
+#endif
+
+#define I2C_READ 1
+#define I2C_WRITE 0
+
+#define I2C_ACK 1
+#define I2C_NACK 0
+
+#define SLAVE_BUFFER_SIZE 0x10
+
+// i2c SCL clock frequency
+#define SCL_CLOCK  800000L
+
+extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
+
+void i2c_master_init(void);
+uint8_t i2c_master_start(uint8_t address);
+void i2c_master_stop(void);
+uint8_t i2c_master_write(uint8_t data);
+uint8_t i2c_master_read(int);
+void i2c_reset_state(void);
+void i2c_slave_init(uint8_t address);
+
+
+static inline unsigned char i2c_start_read(unsigned char addr) {
+  return i2c_master_start((addr << 1) | I2C_READ);
+}
+
+static inline unsigned char i2c_start_write(unsigned char addr) {
+  return i2c_master_start((addr << 1) | I2C_WRITE);
+}
+
+// from SSD1306 scrips
+extern unsigned char i2c_rep_start(unsigned char addr);
+extern void i2c_start_wait(unsigned char addr);
+extern unsigned char i2c_readAck(void);
+extern unsigned char i2c_readNak(void);
+extern unsigned char i2c_read(unsigned char ack);
+
+#define i2c_read(ack)  (ack) ? i2c_readAck() : i2c_readNak();
+
+#endif

keyboards/tkc1800/keymaps/default/config.h

@@ -19,6 +19,11 @@
 
 #include "../../config.h"
 
+#define USE_I2C
+#define SSD1306OLED
+//#define OLED_ROTATE180
+#define SSD1306_ADDRESS 0x3C
+
 // place overrides here
 
 #endif

keyboards/tkc1800/keymaps/default/keymap.c

@@ -14,21 +14,33 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "tkc1800.h"
+#include "LUFA/Drivers/Peripheral/TWI.h"
+#include "i2c.h"
+#include "ssd1306.h"
+
 
 #define MODS_SHFT_MASK  (MOD_BIT(KC_LSHIFT)|MOD_BIT(KC_RSHIFT)|MOD_BIT(KC_LGUI)|MOD_BIT(KC_RGUI))
 #define MODS_GUI_MASK   (MOD_BIT(KC_LGUI)|MOD_BIT(KC_RGUI))
 
+
 // Helpful defines
 #define ______ KC_TRNS
 #define XXXXXX KC_NO
 
-#define _DEFAULT 0
-#define _FUNCTION 1
+//Layers
+
+enum {
+	BASE = 0,
+	FUNCTION,
+};
+
+//13 characters max without re-writing the "Layer: " format in iota_gfx_task_user()
+static char layer_lookup[][14] = {"Base","Function"};
+
 
-//RGB_TOG, RGB_MOD, RGB_HUI, RGB_HUD, RGB_SAI, RGB_SAD, RGB_VAI, RGB_VAD
 
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
-  /* Keymap _BL: (Base Layer) Default Layer
+  /* Keymap BASE: (Base Layer) Default Layer
    * ,-------------------------------------------------------.     ,-------------------.
    * |Esc| F1| F2| F3| F4| | F5| F6| F7| F8| | F9|F10|F11|F12|     |Ins |Home|PgUp|PrSc|
    * `-------------------------------------------------------'     |-------------------|
@@ -45,41 +57,89 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
    * |Ctrl|Gui |Alt |      Space           |Alt |Gui|Ctr|Left |Down|Rght| 0  | .  |    |
    * `---------------------------------------------------------------------------------'
    */
-	[_DEFAULT] = KEYMAP(
+	[BASE] = KEYMAP(
 		KC_ESC, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_INS, KC_HOME, KC_PGUP, KC_PSCR, \
 		                                                                                               KC_DEL, KC_END,  KC_PGDN, KC_SLCK, \
-		KC_TILD, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_BSPC, XXXXXX, KC_NLCK, KC_PSLS, KC_PAST, KC_PAUS, \
+		KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_BSPC, XXXXXX, KC_NLCK, KC_PSLS, KC_PAST, KC_PAUS, \
 		KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_LBRC, KC_RBRC, KC_BSLS, KC_P7, KC_P8, KC_P9, KC_PMNS, \
 		KC_CAPS, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT, XXXXXX, KC_ENT, KC_P4, KC_P5, KC_P6, KC_PPLS, \
-		KC_LSFT, XXXXXX, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT,KC_SLSH, KC_RSFT, KC_UP, KC_P1, KC_P2, KC_P3, KC_PENT, \
-		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, MO(_FUNCTION), KC_RGUI, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0, KC_PDOT, XXXXXX
+		KC_LSFT, XXXXXX, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT,KC_SLSH, KC_RSFT, KC_UP, KC_P1, KC_P2, KC_P3, XXXXXX, \
+		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, KC_RALT, MO(FUNCTION), KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0, KC_PDOT, KC_PENT
 	),
-	[_FUNCTION] = KEYMAP(
+	[FUNCTION] = KEYMAP(
 		KC_ESC, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_INS, KC_HOME, KC_PGUP, KC_PSCR, \
 		                                                                                               KC_DEL, KC_END,  KC_PGDN, KC_SLCK, \
-		KC_TILD, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_BSPC, XXXXXX, KC_NLCK, KC_PSLS, KC_PAST, KC_PAUS, \
+		KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, RESET, XXXXXX, KC_NLCK, KC_PSLS, KC_PAST, KC_PAUS, \
 		KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_LBRC, KC_RBRC, KC_BSLS, KC_P7, KC_P8, KC_P9, KC_PMNS, \
 		KC_CAPS, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT, XXXXXX, KC_ENT, KC_P4, KC_P5, KC_P6, KC_PPLS, \
-		KC_LSFT, XXXXXX, RGB_TOG,RGB_MOD,RGB_HUI,RGB_HUD,RGB_SAI,RGB_SAD,RGB_VAI,RGB_VAD, KC_DOT,KC_SLSH, KC_RSFT, KC_UP, KC_P1, KC_P2, KC_P3, KC_PENT, \
-		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, ______, KC_RGUI, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0, KC_PDOT, XXXXXX
+		KC_LSFT, XXXXXX, RGB_TOG,RGB_MOD,RGB_HUI,RGB_HUD,RGB_SAI,RGB_SAD,RGB_VAI,RGB_VAD, KC_DOT,KC_SLSH, KC_RSFT, KC_UP, KC_P1, KC_P2, KC_P3, XXXXXX, \
+		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, KC_RALT, ______, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0, KC_PDOT, KC_PENT
 	),
 };
 
 // const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) {};
 
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+    return true;
+}
 
-void matrix_init_user(void) {
+void led_set_user(uint8_t usb_led) {
 
 }
+void matrix_init_user(void) {
+  #ifdef USE_I2C
+    i2c_master_init();
+  #ifdef SSD1306OLED
+  // calls code for the SSD1306 OLED
+        _delay_ms(400);
+        TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 800000));
+        iota_gfx_init();   // turns on the display
+  #endif
+  #endif
+    #ifdef AUDIO_ENABLE
+        startup_user();
+    #endif
+}
 
 void matrix_scan_user(void) {
-
+    #ifdef SSD1306OLED
+     iota_gfx_task();  // this is what updates the display continuously
+    #endif
 }
 
-bool process_record_user(uint16_t keycode, keyrecord_t *record) {
-    return true;
+void matrix_update(struct CharacterMatrix *dest,
+                          const struct CharacterMatrix *source) {
+  if (memcmp(dest->display, source->display, sizeof(dest->display))) {
+    memcpy(dest->display, source->display, sizeof(dest->display));
+    dest->dirty = true;
+  }
 }
 
-void led_set_user(uint8_t usb_led) {
+void iota_gfx_task_user(void) {
+#if DEBUG_TO_SCREEN
+  if (debug_enable) {
+    return;
+  }
+#endif
+
+  struct CharacterMatrix matrix;
+
+  matrix_clear(&matrix);
+  matrix_write_P(&matrix, PSTR("TKC1800"));
+  
+  uint8_t layer = biton32(layer_state);
+
+  char buf[40];
+  snprintf(buf,sizeof(buf), "Undef-%d", layer);
+  matrix_write_P(&matrix, PSTR("\nLayer: "));
+  matrix_write(&matrix, layer_lookup[layer]);
 
+  // Host Keyboard LED Status
+  char led[40];
+    snprintf(led, sizeof(led), "\n\n%s  %s  %s",
+            (host_keyboard_leds() & (1<<USB_LED_NUM_LOCK)) ? "NUMLOCK" : "       ",
+            (host_keyboard_leds() & (1<<USB_LED_CAPS_LOCK)) ? "CAPS" : "    ",
+            (host_keyboard_leds() & (1<<USB_LED_SCROLL_LOCK)) ? "SCLK" : "    ");
+  matrix_write(&matrix, led);
+  matrix_update(&display, &matrix);
 }

keyboards/tkc1800/keymaps/wkl/config.h

@@ -0,0 +1,29 @@
+/* Copyright 2017 Mathias Andersson <wraul@dbox.se>
+ *
+ * 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_USER_H
+#define CONFIG_USER_H
+
+#include "../../config.h"
+
+#define USE_I2C
+#define SSD1306OLED
+//#define OLED_ROTATE180
+#define SSD1306_ADDRESS 0x3C
+
+// place overrides here
+
+#endif

keyboards/tkc1800/keymaps/wkl/keymap.c

@@ -0,0 +1,145 @@
+/* Copyright 2017 Mathias Andersson <wraul@dbox.se>
+ *
+ * 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 "tkc1800.h"
+#include "LUFA/Drivers/Peripheral/TWI.h"
+#include "i2c.h"
+#include "ssd1306.h"
+
+
+#define MODS_SHFT_MASK  (MOD_BIT(KC_LSHIFT)|MOD_BIT(KC_RSHIFT)|MOD_BIT(KC_LGUI)|MOD_BIT(KC_RGUI))
+#define MODS_GUI_MASK   (MOD_BIT(KC_LGUI)|MOD_BIT(KC_RGUI))
+
+
+// Helpful defines
+#define ______ KC_TRNS
+#define XXXXXX KC_NO
+
+//Layers
+
+enum {
+	BASE = 0,
+	FUNCTION,
+};
+
+//13 characters max without re-writing the "Layer: " format in iota_gfx_task_user()
+static char layer_lookup[][14] = {"Base","Function"};
+
+
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+  /* Keymap BASE: (Base Layer) Default Layer
+   * ,-------------------------------------------------------.     ,-------------------.
+   * |Esc| F1| F2| F3| F4| | F5| F6| F7| F8| | F9|F10|F11|F12|     |Ins |Home|PgUp|PrSc|
+   * `-------------------------------------------------------'     |-------------------|
+   *                                                               |Del |End |PgDn|ScrL|
+   * ,-----------------------------------------------------------. |-------------------|
+   * | ~ | 1 |  2|  3|  4|  5|  6|  7|  8|  9|  0|  -|  =|Backsp | |NumL| /  | *  |Paus|
+   * |-----------------------------------------------------------| |-------------------|
+   * |Tab  |  Q|  W|  E|  R|  T|  Y|  U|  I|  O|  P|  [|  ]|  \  | | 7  | 8  | 9  | -  |
+   * |-----------------------------------------------------------| |-------------------|
+   * |CAPS   |  A|  S|  D|  F|  G|  H|  J|  K|  L|  ;|  '|Return | | 4  | 5  | 6  | +  |
+   * |-----------------------------------------------------------' |-------------------|
+   * |Shift   |  Z|  X|  C|  V|  B|  N|  M|  ,|  .|  /|Shift  | Up | 1  | 2  | 3  | Ent|
+   * |--------------------------------------------------------'----`--------------|    |
+   * |Ctrl|Gui |Alt |      Space           |Alt |Gui|Ctr|Left |Down|Rght| 0  | .  |    |
+   * `---------------------------------------------------------------------------------'
+   */
+	[BASE] = KEYMAP(
+		KC_ESC, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_INS, KC_HOME, KC_PGUP, KC_PSCR, \
+		                                                                                               KC_DEL, KC_END,  KC_PGDN, KC_SLCK, \
+		KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, KC_BSPC, XXXXXX, KC_NLCK, KC_PSLS, KC_PAST, KC_PAUS, \
+		KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_LBRC, KC_RBRC, KC_BSLS, KC_P7, KC_P8, KC_P9, KC_PMNS, \
+		KC_CAPS, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT, XXXXXX, KC_ENT, KC_P4, KC_P5, KC_P6, KC_PPLS, \
+		KC_LSFT, XXXXXX, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT,KC_SLSH, KC_RSFT, KC_UP, KC_P1, KC_P2, KC_P3, XXXXXX, \
+		KC_LCTL, KC_LALT, XXXXXX, KC_SPC, XXXXXX, MO(FUNCTION), KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0, KC_PDOT, KC_PENT
+	),
+	[FUNCTION] = KEYMAP(
+		KC_ESC, KC_F1, KC_F2, KC_F3, KC_F4, KC_F5, KC_F6, KC_F7, KC_F8, KC_F9, KC_F10, KC_F11, KC_F12, KC_INS, KC_HOME, KC_PGUP, KC_PSCR, \
+		                                                                                               KC_DEL, KC_END,  KC_PGDN, KC_SLCK, \
+		KC_GRV, KC_1, KC_2, KC_3, KC_4, KC_5, KC_6, KC_7, KC_8, KC_9, KC_0, KC_MINS, KC_EQL, RESET, XXXXXX, KC_NLCK, KC_PSLS, KC_PAST, KC_PAUS, \
+		KC_TAB, KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_LBRC, KC_RBRC, KC_BSLS, KC_P7, KC_P8, KC_P9, KC_PMNS, \
+		KC_CAPS, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_QUOT, XXXXXX, KC_ENT, KC_P4, KC_P5, KC_P6, KC_PPLS, \
+		KC_LSFT, XXXXXX, RGB_TOG,RGB_MOD,RGB_HUI,RGB_HUD,RGB_SAI,RGB_SAD,RGB_VAI,RGB_VAD, KC_DOT,KC_SLSH, KC_RSFT, KC_UP, KC_P1, KC_P2, KC_P3, XXXXXX, \
+		KC_LCTL, KC_LGUI, KC_LALT, KC_SPC, XXXXXX, ______, KC_RCTL, KC_LEFT, KC_DOWN, KC_RGHT, KC_P0, KC_PDOT, KC_PENT
+	),
+};
+
+// const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) {};
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+    return true;
+}
+
+void led_set_user(uint8_t usb_led) {
+
+}
+void matrix_init_user(void) {
+  #ifdef USE_I2C
+    i2c_master_init();
+  #ifdef SSD1306OLED
+  // calls code for the SSD1306 OLED
+        _delay_ms(400);
+        TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 800000));
+        iota_gfx_init();   // turns on the display
+  #endif
+  #endif
+    #ifdef AUDIO_ENABLE
+        startup_user();
+    #endif
+}
+
+void matrix_scan_user(void) {
+    #ifdef SSD1306OLED
+     iota_gfx_task();  // this is what updates the display continuously
+    #endif
+}
+
+void matrix_update(struct CharacterMatrix *dest,
+                          const struct CharacterMatrix *source) {
+  if (memcmp(dest->display, source->display, sizeof(dest->display))) {
+    memcpy(dest->display, source->display, sizeof(dest->display));
+    dest->dirty = true;
+  }
+}
+
+void iota_gfx_task_user(void) {
+#if DEBUG_TO_SCREEN
+  if (debug_enable) {
+    return;
+  }
+#endif
+
+  struct CharacterMatrix matrix;
+
+  matrix_clear(&matrix);
+  matrix_write_P(&matrix, PSTR("TKC1800"));
+  
+  uint8_t layer = biton32(layer_state);
+
+  char buf[40];
+  snprintf(buf,sizeof(buf), "Undef-%d", layer);
+  matrix_write_P(&matrix, PSTR("\nLayer: "));
+  matrix_write(&matrix, layer_lookup[layer]);
+
+  // Host Keyboard LED Status
+  char led[40];
+    snprintf(led, sizeof(led), "\n\n%s  %s  %s",
+            (host_keyboard_leds() & (1<<USB_LED_NUM_LOCK)) ? "NUMLOCK" : "       ",
+            (host_keyboard_leds() & (1<<USB_LED_CAPS_LOCK)) ? "CAPS" : "    ",
+            (host_keyboard_leds() & (1<<USB_LED_SCROLL_LOCK)) ? "SCLK" : "    ");
+  matrix_write(&matrix, led);
+  matrix_update(&display, &matrix);
+}

keyboards/tkc1800/rules.mk

@@ -45,7 +45,7 @@ OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
 #   Atmel DFU loader 4096
 #   LUFA bootloader  4096
 #   USBaspLoader     2048
-OPT_DEFS += -DBOOTLOADER_SIZE=4096
+OPT_DEFS += -DBOOTLOADER_SIZE=8192
 
 
 # Build Options
@@ -66,3 +66,6 @@ MIDI_ENABLE ?= no            # MIDI controls
 UNICODE_ENABLE ?= no         # Unicode
 BLUETOOTH_ENABLE ?= no       # Enable Bluetooth with the Adafruit EZ-Key HID
 AUDIO_ENABLE ?= no           # Audio output on port C6
+
+SRC = i2c.c \
+	  ssd1306.c