Update docs/assignments/week12.md

docs/assignments/week12.md

@@ -129,18 +129,22 @@ This tutorial [^5] was created using..
 Use the three backticks to separate code.
 
 ```
-// the setup function runs once when you press reset or power the board
+int pump = 9;
+
 void setup() {
-  // initialize digital pin LED_BUILTIN as an output.
-  pinMode(LED_BUILTIN, OUTPUT);
+ pinMode(pump, OUTPUT);
 }
 
-// the loop function runs over and over again forever
 void loop() {
-  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
-  delay(1000);                       // wait for a second
-  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
-  delay(1000);                       // wait for a second
+ for(int i=70; i<255; i=i+10){
+ analogWrite(pump, i);
+ delay(200);
+ }
+
+ for(int i=255; i>70; i=i-10){
+ analogWrite(pump, i);
+ delay(200);
+ }
 }
 ```