diff --git a/Cargo.lock b/Cargo.lock
index 582faf5..8153ae3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3,10 +3,16 @@
 version = 4
 
 [[package]]
-name = "az"
-version = "1.3.0"
+name = "autocfg"
+version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be5eb007b7cacc6c660343e96f650fedf4b5a77512399eb952ca6642cf8d13f7"
+checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
+
+[[package]]
+name = "az"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7b7e4c2464d97fe331d41de9d5db0def0a96f4d823b8b32a2efd503578988973"
 
 [[package]]
 name = "bare-metal"
@@ -61,6 +67,7 @@ checksum = "8ec610d8f49840a5b376c69663b6369e71f4b34484b9b2eb29fb918d92516cb9"
 dependencies = [
  "bare-metal",
  "bitfield",
+ "critical-section",
  "embedded-hal 0.2.7",
  "volatile-register",
 ]
@@ -91,6 +98,15 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "790eea4361631c5e7d22598ecd5723ff611904e3344ce8720784c93e3d83d40b"
 
+[[package]]
+name = "critical-section-lock-mut"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbb9762738c1ef9d31b7586c00c0158d20025a734f9f6905282c1fc5a2e182f0"
+dependencies = [
+ "critical-section",
+]
+
 [[package]]
 name = "crunchy"
 version = "0.2.4"
@@ -106,6 +122,29 @@ dependencies = [
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "embedded-graphics"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e8da660bb0c829b34a56a965490597f82a55e767b91f9543be80ce8ccb416fe"
+dependencies = [
+ "az",
+ "byteorder",
+ "embedded-graphics-core",
+ "float-cmp",
+ "micromath",
+]
+
+[[package]]
+name = "embedded-graphics-core"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95743bef3ff70fcba3930246c4e6872882bbea0dcc6da2ca860112e0cd4bd09f"
+dependencies = [
+ "az",
+ "byteorder",
+]
+
 [[package]]
 name = "embedded-hal"
 version = "0.2.7"
@@ -122,6 +161,16 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "361a90feb7004eca4019fb28352a9465666b24f840f5c3cddf0ff13920590b89"
 
+[[package]]
+name = "embedded-hal-bus"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "513e0b3a8fb7d3013a8ae17a834283f170deaf7d0eeab0a7c1a36ad4dd356d22"
+dependencies = [
+ "critical-section",
+ "embedded-hal 1.0.0",
+]
+
 [[package]]
 name = "embedded-io"
 version = "0.7.1"
@@ -136,9 +185,9 @@ checksum = "a21dea9854beb860f3062d10228ce9b976da520a73474aed3171ec276bc0c032"
 
 [[package]]
 name = "fixed"
-version = "1.31.0"
+version = "1.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9af2cbf772fa6d1c11358f92ef554cb6b386201210bcf0e91fb7fba8a907fb40"
+checksum = "707070ccf8c4173548210893a0186e29c266901b71ed20cd9e2ca0193dfe95c3"
 dependencies = [
  "az",
  "bytemuck",
@@ -146,6 +195,15 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "float-cmp"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "98de4bbd547a563b716d8dfa9aad1cb19bfab00f4fa09a6a4ed21dbcf44ce9c4"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "half"
 version = "2.7.1"
@@ -253,13 +311,21 @@ version = "0.1.0"
 dependencies = [
  "cortex-m",
  "cortex-m-rt",
+ "critical-section",
+ "critical-section-lock-mut",
+ "embedded-graphics",
  "embedded-hal 1.0.0",
+ "embedded-hal-bus",
  "embedded-io",
  "heapless 0.9.3",
  "libm",
  "lsm303agr",
  "microbit-v2",
+ "mipidsi",
+ "nrf52833-hal",
  "panic-halt",
+ "panic-rtt-target",
+ "rtt-target",
 ]
 
 [[package]]
@@ -282,6 +348,23 @@ dependencies = [
  "microbit-common",
 ]
 
+[[package]]
+name = "micromath"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3c8dda44ff03a2f238717214da50f65d5a53b45cd213a7370424ffdb6fae815"
+
+[[package]]
+name = "mipidsi"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "790ebd28bd67addbccf41b1c0c188c26bb9f5bdcd91d4d6da9bd558e20d97a1d"
+dependencies = [
+ "embedded-graphics-core",
+ "embedded-hal 1.0.0",
+ "heapless 0.8.0",
+]
+
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -307,6 +390,7 @@ dependencies = [
  "cfg-if",
  "cortex-m",
  "embedded-dma",
+ "embedded-hal 0.2.7",
  "embedded-hal 1.0.0",
  "embedded-io",
  "embedded-storage",
@@ -351,12 +435,32 @@ dependencies = [
  "vcell",
 ]
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "panic-halt"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a513e167849a384b7f9b746e517604398518590a9142f4846a32e3c2a4de7b11"
 
+[[package]]
+name = "panic-rtt-target"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8116ffce1f89818647b84fba66d16cfdf3c0bee3c9320e606588d3e7415ce7"
+dependencies = [
+ "critical-section",
+ "portable-atomic",
+ "rtt-target",
+]
+
 [[package]]
 name = "portable-atomic"
 version = "1.13.1"
@@ -409,6 +513,17 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "76afc826de14238e6e8c374ddcc1fa19e374fd8dd986b0d2af0d02377261d83c"
 
+[[package]]
+name = "rtt-target"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7afed1f4302eeba88c601636cf2c554c45e1cbb464bab44c6012bab0e71473c"
+dependencies = [
+ "critical-section",
+ "portable-atomic",
+ "ufmt-write",
+]
+
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -479,6 +594,12 @@ version = "1.20.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "40ce102ab67701b8526c123c1bab5cbe42d7040ccfd0f64af1a385808d2f43de"
 
+[[package]]
+name = "ufmt-write"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e87a2ed6b42ec5e28cc3b94c09982969e9227600b2e3dcbc1db927a84c06bd69"
+
 [[package]]
 name = "unicase"
 version = "2.9.0"
diff --git a/Cargo.toml b/Cargo.toml
index 4686acc..d736b9a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,8 +8,16 @@ cortex-m-rt = "0.7.5"
 microbit-v2 = "0.16.0"
 embedded-hal = "1.0.0"
 panic-halt = "1.0.0"
-cortex-m = "0.7.7"
+cortex-m = { version = "0.7.7", features = ["critical-section-single-core"] }
 embedded-io = "0.7.1"
 heapless = "0.9.3"
 lsm303agr = "1.1.0"
 libm = "0.2.16"
+panic-rtt-target = "0.2.0"
+rtt-target = "0.6.2"
+critical-section = "1.2.0"
+critical-section-lock-mut = "0.1.2"
+nrf52833-hal = "0.19.0"
+mipidsi = "0.10.0"
+embedded-graphics = "0.8.2"
+embedded-hal-bus = "0.3.0"
diff --git a/src/bin/analog.rs b/src/bin/analog.rs
new file mode 100644
index 0000000..6dabc47
--- /dev/null
+++ b/src/bin/analog.rs
@@ -0,0 +1,60 @@
+#![no_main]
+#![no_std]
+
+use cortex_m_rt::entry;
+use embedded_hal::delay::DelayNs;
+use microbit::{Board, adc::Default};
+use nrf52833_hal::{Saadc, Timer, saadc::SaadcConfig};
+use panic_rtt_target as _;
+use rtt_target::{rprintln, rtt_init_print};
+
+const THRESHOLD: i16 = 16;
+
+const LEFT_VALUE: i16 = -1;
+const LEFT_NAME: &str = "LEFT";
+
+const UP_VALUE: i16 = 117;
+const UP_NAME: &str = "UP";
+
+const DOWN_VALUE: i16 = 269;
+const DOWN_NAME: &str = "DOWN";
+
+const RIGHT_VALUE: i16 = 413;
+const RIGHT_NAME: &str = "RIGHT";
+
+const SEL_VALUE: i16 = 609;
+const SEL_NAME: &str = "SELECT";
+
+const NO_VALUE: i16 = 845;
+const NO_NAME: &str = "NO";
+
+#[entry]
+fn main() -> ! {
+    rtt_init_print!();
+    let board = Board::take().unwrap();
+    let mut timer = Timer::new(board.TIMER0);
+
+    let saadc_config = SaadcConfig::default_10bit();
+    let mut saadc = Saadc::new(board.ADC, saadc_config);
+    let mut saadc_pin = board.edge.e00;
+
+    loop {
+        if let Ok(value) = saadc.read_channel(&mut saadc_pin) {
+            rprintln!("value is {}", value);
+
+            for (test, name) in [
+                ( LEFT_VALUE, LEFT_NAME ),
+                ( UP_VALUE, UP_NAME ),
+                ( DOWN_VALUE, DOWN_NAME ),
+                ( RIGHT_VALUE, RIGHT_NAME ),
+                ( SEL_VALUE, SEL_NAME ), 
+                ( NO_VALUE, NO_NAME ),
+            ] {
+                if value > test - THRESHOLD && value < test + THRESHOLD {
+                    rprintln!("detected {}", name);
+                }
+            }
+        }
+        timer.delay_ms(1000);
+    }
+}
diff --git a/src/bin/compass.rs b/src/bin/compass.rs
new file mode 100644
index 0000000..935a501
--- /dev/null
+++ b/src/bin/compass.rs
@@ -0,0 +1,75 @@
+#![no_main]
+#![no_std]
+
+use core::f32::consts::PI;
+
+use cortex_m_rt::entry;
+use embedded_hal::delay::DelayNs;
+use libm::{atan2f, floorf};
+use lsm303agr::{Lsm303agr, MagMode, MagOutputDataRate};
+use microbit::{display::blocking::Display, hal::{Timer, Twim}, pac::twim0::frequency::FREQUENCY_A};
+use panic_halt as _;
+
+mod calibration {
+    type Vec = (i32, i32, i32);
+
+    const CAL_CENTER: Vec = (-12892, 21810, -1080);
+    const CAL_SCALE: Vec = (1066, 1049, 1072);
+
+    pub fn calibrate(v: Vec) -> Vec {
+        let mut out = (-v.1, -v.0, v.2);
+        out.0 = ((out.0 - CAL_CENTER.0) * CAL_SCALE.0) >> 10;
+        out.1 = ((out.1 - CAL_CENTER.1) * CAL_SCALE.1) >> 10;
+        out.2 = ((out.2 - CAL_CENTER.2) * CAL_SCALE.2) >> 10;
+        (-out.1, out.0, out.2)
+    }
+}
+
+#[entry]
+fn main() -> ! {
+    let board = microbit::Board::take().unwrap();
+
+    let i2c = Twim::new(board.TWIM0, board.i2c_internal.into(), FREQUENCY_A::K100);
+    let mut timer = Timer::new(board.TIMER0);
+    let mut display = Display::new(board.display_pins);
+
+    let mut sensor = Lsm303agr::new_with_i2c(i2c);
+    sensor.init().unwrap();
+    sensor.set_mag_mode_and_odr(&mut timer, MagMode::HighResolution, MagOutputDataRate::Hz10).unwrap();
+    let mut sensor = sensor.into_mag_continuous().ok().unwrap();
+
+    let mut leds = [[0u8; 5]; 5];
+
+    let indices = [
+        (2, 0) /* W */, (3, 0) /* W-SW */, (4, 0) /* SW */, (4, 1) /* S-SW */,
+        (4, 2) /* S */, (4, 3) /* S-SE */, (4, 4) /* SE */, (3, 4) /* E-SE */,
+        (2, 4) /* E */, (1, 4) /* E-NE */, (0, 4) /* NE */, (0, 3) /* N-NE */,
+        (0, 2) /* N */, (0, 1) /* N-NW */, (0, 0) /* NW */, (1, 0) /* W-NW */,
+    ];
+    
+    loop {
+        while !sensor.mag_status().unwrap().xyz_new_data() {
+            timer.delay_ms(1u32);
+        }
+
+        let (x, y, _) = calibration::calibrate(sensor.magnetic_field().unwrap().xyz_nt());
+        //let (x, y, _) = sensor.magnetic_field().unwrap().xyz_nt();
+
+        let theta = atan2f(y as f32, x as f32);
+
+        let seg = floorf(16.0 * theta / PI) as i8;
+
+        let index = if seg >= 15 || seg <= -15 {
+            8
+        } else if seg >= 0 {
+            (seg / 2) as usize
+        } else {
+            ((31 + seg) / 2) as usize
+        };
+        let (r, c) = indices[index];
+        leds[r][c] = 255u8;
+        display.show(&mut timer, leds, 100);
+        leds[r][c] = 0u8;
+        display.clear();
+    }
+}
diff --git a/src/bin/display.rs b/src/bin/display.rs
new file mode 100644
index 0000000..ea1992b
--- /dev/null
+++ b/src/bin/display.rs
@@ -0,0 +1,64 @@
+#![no_main]
+#![no_std]
+
+use cortex_m_rt::entry;
+use embedded_graphics::{pixelcolor::Rgb565, prelude::{DrawTarget, Point, WebColors}, primitives::Rectangle};
+use embedded_hal::digital::OutputPin;
+use embedded_hal_bus::spi::ExclusiveDevice;
+use microbit::Board;
+use mipidsi::{Builder, interface::SpiInterface, models, options::ColorInversion};
+use nrf52833_hal::{Timer, gpio::Level, spi::{self, Spi}, spim};
+use panic_rtt_target as _;
+use rtt_target::{rprintln, rtt_init_print};
+
+#[entry]
+fn main() -> ! {
+    rtt_init_print!();
+    let board = Board::take().unwrap();
+
+    let mut timer0 = Timer::new(board.TIMER0);
+    let mut timer1 = Timer::new(board.TIMER1);
+
+    board.pins.p0_01.into_push_pull_output(Level::Low).set_high();
+    
+    let spi_pins = spi::Pins {
+        sck: Some(board.pins.p0_17.into_push_pull_output(Level::Low).degrade()),
+        mosi: Some(board.pins.p0_13.into_push_pull_output(Level::Low).degrade()),
+        miso: None,
+    };
+
+    let bus = Spi::new(board.SPI0, spi_pins, spi::Frequency::M8, spim::MODE_3);
+    let spi = ExclusiveDevice::new(
+        bus,
+        board.edge.e16.into_push_pull_output(Level::Low),
+        &mut timer0,
+    ).unwrap();
+    
+    let mut buffer = [0u8; 512];
+
+    let interface = SpiInterface::new(
+        spi,
+        board.edge.e08.into_push_pull_output(Level::Low),
+        &mut buffer,
+    );
+    
+    let mut display = Builder::new(models::ST7789, interface)
+        .display_size(240, 320)
+        .invert_colors(ColorInversion::Inverted)
+        .init(&mut timer1).unwrap();
+
+    display.clear(Rgb565::CSS_GREEN).unwrap();
+    display.fill_solid(
+        &Rectangle::with_corners(
+            Point::new(100, 100),
+            Point::new(150, 150),
+        ),
+        Rgb565::CSS_ROYAL_BLUE,
+    ).unwrap();
+
+    rprintln!("Should be done here");
+
+    loop {
+        continue;
+    }
+}
diff --git a/src/bin/interrupt.rs b/src/bin/interrupt.rs
new file mode 100644
index 0000000..6314357
--- /dev/null
+++ b/src/bin/interrupt.rs
@@ -0,0 +1,63 @@
+#![no_main]
+#![no_std]
+
+use core::sync::atomic::AtomicUsize;
+
+use cortex_m::asm;
+use cortex_m_rt::entry;
+use critical_section_lock_mut::LockMut;
+use microbit::{Board, hal::{Timer, gpiote::Gpiote}, pac::{self, interrupt}};
+use panic_rtt_target as _;
+use rtt_target::{rprintln, rtt_init_print};
+
+static COUNTER: AtomicUsize = AtomicUsize::new(0);
+static GPIOTE_PERIPHERAL: LockMut<Gpiote> = LockMut::new();
+static DEBOUNCE_TIMER: LockMut<Timer<pac::TIMER0>> = LockMut::new();
+
+const DEBOUNCE_TIME: u32 = 100 * 1_000_000 / 1000;
+
+#[interrupt]
+fn GPIOTE() {
+    DEBOUNCE_TIMER.with_lock(|t| {
+        if t.read() == 0 {
+            let _ = COUNTER.fetch_add(1, core::sync::atomic::Ordering::AcqRel);
+            t.start(DEBOUNCE_TIME);
+        }
+    });
+    GPIOTE_PERIPHERAL.with_lock(|g| {
+        g.channel0().reset_events();
+    });
+}
+
+#[entry]
+fn main() -> ! {
+    rtt_init_print!();
+    let board = Board::take().unwrap();
+    let button_a = board.buttons.button_a.into_floating_input();
+    
+    let gpiote = Gpiote::new(board.GPIOTE);
+    let channel = gpiote.channel0();
+    channel.input_pin(&button_a.degrade())
+        .hi_to_lo()
+        .enable_interrupt();
+    channel.reset_events();
+    GPIOTE_PERIPHERAL.init(gpiote);
+
+    let mut timer = Timer::new(board.TIMER0);
+    timer.disable_interrupt();
+    timer.reset_event();
+    DEBOUNCE_TIMER.init(timer);
+
+    unsafe { pac::NVIC::unmask(pac::Interrupt::GPIOTE) };
+    pac::NVIC::unpend(pac::Interrupt::GPIOTE);
+
+    let mut cur_count = 0;
+    loop {
+        asm::wfi();
+        let count = COUNTER.load(core::sync::atomic::Ordering::Acquire);
+        if count > cur_count {
+            rprintln!("ouch {}", count);
+            cur_count = count;
+        }
+    }
+}