ldr draft

src/SUMMARY.md

@@ -34,5 +34,9 @@
         - [got module](./buzzer/got-module.md)
         - [Play](./buzzer/play.md)
     - [Active Beep](./buzzer/active-beep.md)
+- [LDR](./ldr/index.md)
+    - [ADC](./ldr/adc.md)
+    - [LDR and LED](./ldr/ldr-led.md)
+
 
 - [Resources](./resources.md)

src/ldr/adc.md

@@ -0,0 +1,3 @@
+# ADC (Analog to Digital Converter)
+
+# TODO: Explanation

src/ldr/index.md

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+## LDR (Light Dependent Resistor)
+
+# TODO: Explanation

src/ldr/ldr-led.md

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+## Turn on LED(or Lamp) in low Light with Pico 
+
+In this exercise, we'll control an LED based on ambient light levels. The goal is to automatically turn on the LED in low light conditions. 
+
+You can try this in a closed room by turning the room light on and off. When you turn off the room-light, the LED should turn on, given that the room is dark enough, and turn off again when the room-light is switched back on. Alternatively, you can adjust the sensitivity threshold or cover the light sensor (LDR) with your hand or some object to simulate different light levels.
+
+Note: You may need to adjust the ADC threshold based on your room's lighting conditions and the specific LDR you are using.
+
+# TODO: Explanation
+
+```rust
+bind_interrupts!(struct Irqs {
+    ADC_IRQ_FIFO => InterruptHandler;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_rp::init(Default::default());
+    let mut adc = Adc::new(p.ADC, Irqs, Config::default());
+
+    let mut p26 = Channel::new_pin(p.PIN_26, Pull::None);
+    let mut led = Output::new(p.PIN_15, Level::Low);
+
+    loop {
+        let level = adc.read(&mut p26).await.unwrap();
+        if level > 3800 {
+            led.set_high();
+        } else {
+            led.set_low();
+        }
+        Timer::after_secs(1).await;
+    }
+}
+```