diff --git a/CMakeLists.txt b/CMakeLists.txt
index 699156b..89937a8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,7 @@ set(CMAKE_CXX_STANDARD 17)
 pico_sdk_init()
 
 add_executable(test
-	main.c
+	main.c oled.c
 	ufb/framebuffer.c ufb/utf8.c ufb/font.c ufb/fb_7seg.c ufb/fb_text.c
 )
 
diff --git a/main.c b/main.c
index b785904..3a98a31 100644
--- a/main.c
+++ b/main.c
@@ -7,191 +7,23 @@
 
 #include "framebuffer.h"
 #include "fb_text.h"
-
-const uint LED_PIN = 25;
-const uint DC_PIN = 20;
-const uint RST_PIN = 21;
+#include "oled.h"
 
 #define SSD1309_HEIGHT 64
 
-
+const uint LED_PIN = 25;
 
 /* Picotool info */
-// Make the SPI pins available to picotool
-bi_decl(bi_2pins_with_func(PICO_DEFAULT_SPI_TX_PIN, PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI))
-bi_decl(bi_1pin_with_name(PICO_DEFAULT_SPI_CSN_PIN, "SPI CS"))
-bi_decl(bi_1pin_with_name(DC_PIN, "OLED DC"))
-bi_decl(bi_1pin_with_name(RST_PIN, "OLED RST"))
+bi_decl(bi_program_description("OLED demo"))
 bi_decl(bi_1pin_with_name(LED_PIN, "Blink LED"))
 
-static inline void cs_select() {
-    asm volatile("nop \n nop \n nop");
-    gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 0);  // Active low
-    asm volatile("nop \n nop \n nop");
-}
-
-static inline void cs_deselect() {
-    asm volatile("nop \n nop \n nop");
-    gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 1);
-    asm volatile("nop \n nop \n nop");
-}
-
-static inline void dc_command() {
-    gpio_put(DC_PIN, 0);
-}
-
-static inline void dc_data() {
-    gpio_put(DC_PIN, 1);
-}
-
-static void oled_command16(uint8_t cmd, uint8_t arg) {
-    uint8_t buf[2];
-    buf[0] = cmd;
-    buf[1] = arg;
-    dc_command();
-    cs_select();
-    spi_write_blocking(spi_default, buf, 2);
-    cs_deselect();
-}
-
-static void oled_command(uint8_t cmd) {
-    dc_command();
-    cs_select();
-    spi_write_blocking(spi_default, &cmd, 1);
-    cs_deselect();
-}
-
-static void oled_reset() {
-    // Issue a display reset
-    gpio_put(RST_PIN, 0);
-    sleep_ms(1);
-    gpio_put(RST_PIN, 1);
-    sleep_ms(1);
-}
-
 int main() {
-	bi_decl(bi_program_description("This is a test binary."));
-	bi_decl(bi_1pin_with_name(LED_PIN, "On-board LED"));
-
-
-
 	stdio_init_all();
 
     gpio_init(LED_PIN);
     gpio_set_dir(LED_PIN, GPIO_OUT);
 
-
-    // This example will use SPI0 at 10MHz.
-    spi_init(spi_default, 10 * 1000 * 1000);
-    gpio_set_function(PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI);
-    gpio_set_function(PICO_DEFAULT_SPI_TX_PIN, GPIO_FUNC_SPI);
-
-    // Chip select is active-low, so we'll initialise it to a driven-high state
-    gpio_init(PICO_DEFAULT_SPI_CSN_PIN);
-    gpio_set_dir(PICO_DEFAULT_SPI_CSN_PIN, GPIO_OUT);
-    gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 1);
-
-    gpio_init(DC_PIN);
-    gpio_set_dir(DC_PIN, GPIO_OUT);
-
-    gpio_init(RST_PIN);
-    gpio_set_dir(RST_PIN, GPIO_OUT);
-
-    oled_reset();
-
-    // simplified display init
-
-    oled_command(0xAE); /* Display off */
-    //oled_command16(0xD5, 0xF0); // set clock speed
-
-    oled_command16(0x20, 0b00); // page addressing mode: 00 - horizontal, 01 vertical, 10 page
-
-    oled_command16(0x81, 0xFF);
-    
-    //oled_command16(0xD9, 0xff);
-
-    oled_command(0xAF); /*--turn on SSD1309 panel */
-
-#if 0
-
-    /* Init OLED */
-    oled_command(0xAE); /* Display off */
-
-    // Configure the display - only setting things that differ from the default:
-
-
-    oled_command16(0x20, 0b10); /* Set Memory Addressing Mode */
-    /* 00,Horizontal Addressing Mode; 01,Vertical Addressing Mode; */
-    /* 10,Page Addressing Mode (RESET); 11,Invalid */
-
-    oled_command(0xB0); /*Set Page Start Address for Page Addressing Mode, B0-B7 */
-
-#ifdef SSD1309_MIRROR_VERT
-    oled_command(0xC1);
-#else
-    oled_command(0xC0);
-#endif
-
-    // lower nibble is value
-    oled_command(0x00); /*---set low column address 00~0F  */
-
-    oled_command(0x10); /*---set high column address 10~1F */
-
-    oled_command(0x40); /*--set start line address - 40~7F */
-
-    oled_command16(0x81, 0x7F); /*--set contrast control register - ? 0xFF */
-
-#ifdef SSD1309_MIRROR_HORIZ
-    oled_command(0xA1);
-#else
-    oled_command(0xA0);
-#endif
-
-#ifdef SSD1309_INVERSE_COLOR
-    oled_command(0xA7); /*--set inverse color */
-#else
-    oled_command(0xA6); /*--set normal color */
-#endif
-
-    /*--set multiplex ratio(1 to 64) */
-#if (SSD1309_HEIGHT == 32)
-    oled_command16(0xA8, 0x1F);
-#elif (SSD1309_HEIGHT == 64)
-    oled_command16(0xA8, 0x3F);
-#else
-#error "bad height"
-#endif
-
-    oled_command(0xA4); /* 0xA4, Output follows RAM content;0xa5,Output ignores RAM content */
-
-    oled_command16(0xD3, 0x00); /*-set display offset */
-
-    oled_command16(0xD5, 0xF0); /*--set display clock divide ratio/oscillator frequency */
-
-    oled_command16(0xD9, 0x22); /*--set pre-charge period */
-
-    /*--set com pins hardware configuration */
-#if (SSD1309_HEIGHT == 32)
-    oled_command16(0xDA, 0x02);
-#elif (SSD1309_HEIGHT == 64)
-    oled_command16(0xDA, 0x12);
-#else
-#error "bad height"
-#endif
-
-    oled_command16(0xDB, 0x34); /*--set vcomh */
-
-    // ??? not listed in the datasheet
-//    oled_command(0x8D); /*--set DC-DC enable */
-//    oled_command(0x14); /*                   */
-
-    oled_command(0xAF); /*--turn on SSD1309 panel */
-
-
-    oled_command(0xA5); // entire display on - for test
-
-#endif
-
+    oled_init();
 
 #define ZIR_W 12
 #define ZIR_H 24
@@ -239,27 +71,18 @@ int main() {
 
     fb_clear();
     fb_bitmap(5, 5, ZIR_W, ZIR_H, zirafa, 1);
-    fb_text(40, 23, "MEOW", FONT_DOUBLE, 1);
-    fb_text(50, 35, "meow", FONT_DOUBLE, 1);
+    fb_text(40, 35, "MEOW", FONT_DOUBLE, 1);
+    fb_text(50, 20, "meow", FONT_DOUBLE, 1);
     fb_frame(0, 0, 128, 64, 2, 1);
     fb_blit();
 
-//    dc_data();
-//    cs_select();
-//    uint8_t pattern = 0;
-//    for (uint i = 0; i < 128 * 8; i++) {
-//        pattern = i & 0xFF;
-//        spi_write_blocking(spi_default, &pattern, 1);
-//    }
-//    cs_deselect();
-
 	while (1) {
-        oled_command(0xA6); // invert
+        oled_invert(true);
 
 		gpio_put(LED_PIN, 0);
 		sleep_ms(1000);
 
-        oled_command(0xA7); // uninvert
+        oled_invert(false);
 
 		gpio_put(LED_PIN, 1);
 
@@ -267,10 +90,3 @@ int main() {
 		sleep_ms(1000);
 	}
 }
-
-void fb_blit() {
-    dc_data();
-    cs_select();
-    spi_write_blocking(spi_default, fb, FB_LEN);
-    cs_deselect();
-}
diff --git a/oled.c b/oled.c
new file mode 100644
index 0000000..6eec4e0
--- /dev/null
+++ b/oled.c
@@ -0,0 +1,199 @@
+//
+// Created by MightyPork on 2022/12/28.
+//
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/gpio.h"
+#include "pico/binary_info.h"
+
+#include "hardware/spi.h"
+
+#include "framebuffer.h"
+
+static const uint DC_PIN = 20;
+static const uint RST_PIN = 21;
+
+#define SSD1309_HEIGHT 64
+
+/* Picotool info */
+// Make the SPI pins available to picotool
+bi_decl(bi_2pins_with_func(PICO_DEFAULT_SPI_TX_PIN, PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI))
+bi_decl(bi_1pin_with_name(PICO_DEFAULT_SPI_CSN_PIN, "SPI CS"))
+bi_decl(bi_1pin_with_name(DC_PIN, "OLED DC"))
+bi_decl(bi_1pin_with_name(RST_PIN, "OLED RST"))
+
+static inline void cs_select() {
+    asm volatile("nop \n nop \n nop");
+    gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 0);  // Active low
+    asm volatile("nop \n nop \n nop");
+}
+
+static inline void cs_deselect() {
+    asm volatile("nop \n nop \n nop");
+    gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 1);
+    asm volatile("nop \n nop \n nop");
+}
+
+static inline void dc_command() {
+    gpio_put(DC_PIN, 0);
+}
+
+static inline void dc_data() {
+    gpio_put(DC_PIN, 1);
+}
+
+void oled_command16(uint8_t cmd, uint8_t arg) {
+    uint8_t buf[2];
+    buf[0] = cmd;
+    buf[1] = arg;
+    dc_command();
+    cs_select();
+    spi_write_blocking(spi_default, buf, 2);
+    cs_deselect();
+}
+
+void oled_command(uint8_t cmd) {
+    dc_command();
+    cs_select();
+    spi_write_blocking(spi_default, &cmd, 1);
+    cs_deselect();
+}
+
+void oled_reset() {
+    // Issue a display reset
+    gpio_put(RST_PIN, 0);
+    sleep_ms(1);
+    gpio_put(RST_PIN, 1);
+    sleep_ms(1);
+}
+
+void oled_invert(bool invert) {
+    if (invert) {
+        oled_command(0xA6);
+    } else {
+        oled_command(0xA7);
+    }
+}
+
+void oled_init() {
+    // This example will use SPI0 at 10MHz.
+    spi_init(spi_default, 10 * 1000 * 1000);
+    gpio_set_function(PICO_DEFAULT_SPI_SCK_PIN, GPIO_FUNC_SPI);
+    gpio_set_function(PICO_DEFAULT_SPI_TX_PIN, GPIO_FUNC_SPI);
+
+    // Chip select is active-low, so we'll initialise it to a driven-high state
+    gpio_init(PICO_DEFAULT_SPI_CSN_PIN);
+    gpio_set_dir(PICO_DEFAULT_SPI_CSN_PIN, GPIO_OUT);
+    gpio_put(PICO_DEFAULT_SPI_CSN_PIN, 1);
+
+    gpio_init(DC_PIN);
+    gpio_set_dir(DC_PIN, GPIO_OUT);
+
+    gpio_init(RST_PIN);
+    gpio_set_dir(RST_PIN, GPIO_OUT);
+
+    oled_reset();
+
+    // simplified display init
+
+    oled_command(0xAE); /* Display off */
+    //oled_command16(0xD5, 0xF0); // set clock speed
+
+    oled_command16(0x20, 0b00); // page addressing mode: 00 - horizontal, 01 vertical, 10 page
+
+    oled_command16(0x81, 0xFF); // contrast
+
+    oled_command(0xAF); /*--turn on SSD1309 panel */
+
+#if 0
+
+    /* Init OLED */
+    oled_command(0xAE); /* Display off */
+
+    // Configure the display - only setting things that differ from the default:
+
+
+    oled_command16(0x20, 0b10); /* Set Memory Addressing Mode */
+    /* 00,Horizontal Addressing Mode; 01,Vertical Addressing Mode; */
+    /* 10,Page Addressing Mode (RESET); 11,Invalid */
+
+    oled_command(0xB0); /*Set Page Start Address for Page Addressing Mode, B0-B7 */
+
+#ifdef SSD1309_MIRROR_VERT
+    oled_command(0xC1);
+#else
+    oled_command(0xC0);
+#endif
+
+    // lower nibble is value
+    oled_command(0x00); /*---set low column address 00~0F  */
+
+    oled_command(0x10); /*---set high column address 10~1F */
+
+    oled_command(0x40); /*--set start line address - 40~7F */
+
+    oled_command16(0x81, 0x7F); /*--set contrast control register - ? 0xFF */
+
+#ifdef SSD1309_MIRROR_HORIZ
+    oled_command(0xA1);
+#else
+    oled_command(0xA0);
+#endif
+
+#ifdef SSD1309_INVERSE_COLOR
+    oled_command(0xA7); /*--set inverse color */
+#else
+    oled_command(0xA6); /*--set normal color */
+#endif
+
+    /*--set multiplex ratio(1 to 64) */
+#if (SSD1309_HEIGHT == 32)
+    oled_command16(0xA8, 0x1F);
+#elif (SSD1309_HEIGHT == 64)
+    oled_command16(0xA8, 0x3F);
+#else
+#error "bad height"
+#endif
+
+    oled_command(0xA4); /* 0xA4, Output follows RAM content;0xa5,Output ignores RAM content */
+
+    oled_command16(0xD3, 0x00); /*-set display offset */
+
+    oled_command16(0xD5, 0xF0); /*--set display clock divide ratio/oscillator frequency */
+
+    oled_command16(0xD9, 0x22); /*--set pre-charge period */
+
+    /*--set com pins hardware configuration */
+#if (SSD1309_HEIGHT == 32)
+    oled_command16(0xDA, 0x02);
+#elif (SSD1309_HEIGHT == 64)
+    oled_command16(0xDA, 0x12);
+#else
+#error "bad height"
+#endif
+
+    oled_command16(0xDB, 0x34); /*--set vcomh */
+
+    // ??? not listed in the datasheet
+//    oled_command(0x8D); /*--set DC-DC enable */
+//    oled_command(0x14); /*                   */
+
+    oled_command(0xAF); /*--turn on SSD1309 panel */
+
+
+    oled_command(0xA5); // entire display on - for test
+
+#endif
+}
+
+void oled_data(uint8_t *data, size_t len) {
+    dc_data();
+    cs_select();
+    spi_write_blocking(spi_default, data, len);
+    cs_deselect();
+}
+
+void fb_blit() {
+    oled_data(fb, FB_LEN);
+}
diff --git a/oled.h b/oled.h
new file mode 100644
index 0000000..c74c270
--- /dev/null
+++ b/oled.h
@@ -0,0 +1,19 @@
+//
+// Created by MightyPork on 2022/12/28.
+//
+
+#ifndef TEST_PROJECT_OLED_H
+#define TEST_PROJECT_OLED_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+void oled_init();
+void oled_reset();
+void oled_command(uint8_t cmd);
+void oled_command16(uint8_t cmd, uint8_t arg);
+void oled_invert(bool invert);
+
+void oled_data(uint8_t *data, size_t len);
+
+#endif //TEST_PROJECT_OLED_H