docs

docs/Assignments/week_12_machine_building/machine_building.md

@@ -29,7 +29,10 @@ Starting the project we used last years prototype as our starting point.
 (Our robot already strapped with an Ultrasonic and a Time of flight sensor)
 Dylan and I wanted to do the coding and electronics of the robot and Patrick and Irja took the designing and building part of the robot.
 
-We realized quickly that we only had 2 ports left over because all other where in use by the arduino motor drive hat. These 2 ports that where left over where the I2C port SDA and SCL. So I thought let's use ToF sensors since you can hook up multiple on I2C. After some digging in the datasheet I found out that wouldn't work because whenever you assign a I2C address to a VL53X1L it would forget it next power cycle. So I thought: what if I used a multiplexer connected to all the XSHUT pins of the ToF sensor to turn them on one by one and assign them each their own I2C address on startup.
+We realized quickly that we only had 2 ports left over because all other where in use by the arduino motor drive hat. These 2 ports that where left over where the I2C port SDA and SCL.
+![alt text](image-14.jpg)
+
+So I thought let's use ToF sensors since you can hook up multiple on I2C. After some digging in the datasheet I found out that wouldn't work because whenever you assign a I2C address to a VL53X1L it would forget it next power cycle. So I thought: what if I used a multiplexer connected to all the XSHUT pins of the ToF sensor to turn them on one by one and assign them each their own I2C address on startup.
 ![alt text](image-11.jpg)
 
 Luckily we had the I2C multiplexer [PA9555](https://www.nxp.com/docs/en/data-sheet/PCA9555.pdf). So I used I2C for everything because I had limited pins. So I started designing a circuit.
@@ -500,4 +503,60 @@ So the main MCU would do all the thinking and readings from the sensors and the
     }
     ```
 
-So now I could send commands to the motors over Serial and see the motors spin in realtime. The command is structured like this. `1,500` Where 1 is the motor number and 500 is the speed of the motor. So like this I could control every motor separately. 
+So now I could send commands to the motors over Serial and see the motors spin in realtime. The command is structured like this. `1,500` Where 1 is the motor number and 500 is the speed of the motor. So like this I could control every motor separately. 
+
+## Using an ESPC6
+Since we couldn't use the Arduino for any logic stuff we needed something else to talk to the arduino that's where the ESP came in to play. I only attached the Esp Tx to the Rx of the arduino because these 2 mcu's work on different logic levels and I was concerned that the arduino may fry the the ESP if it send anything back.  
+//TODO: add more docs
+
+## Getting ultrasonic sensors to work (Again)
+On the last day I tried to connect everything together. I first started out with one ultrasonic sensor but I noticed I wasn't getting any data from it. So I started debugging and only running the code necessary to get the sensor running but that also didn't work
+
+??? Code
+    ```cpp
+    int trigPin = D4;    // Trigger
+    int echoPin = D9;    // Echo
+    long duration, cm, inches;
+    
+    void setup() {
+      //Serial Port begin
+      Serial.begin(9600);
+      //Define inputs and outputs
+      pinMode(trigPin, OUTPUT);
+      pinMode(echoPin, INPUT);
+    }
+    
+    void loop() {
+      // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
+      // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
+      digitalWrite(trigPin, LOW);
+      delayMicroseconds(5);
+      digitalWrite(trigPin, HIGH);
+      delayMicroseconds(10);
+      digitalWrite(trigPin, LOW);
+    
+      // Read the signal from the sensor: a HIGH pulse whose
+      // duration is the time (in microseconds) from the sending
+      // of the ping to the reception of its echo off of an object.
+      duration = pulseIn(echoPin, HIGH);
+    
+      // Convert the time into a distance
+      cm = (duration/2) / 29.1;     // Divide by 29.1 or multiply by 0.0343
+      inches = (duration/2) / 74;   // Divide by 74 or multiply by 0.0135
+      
+      Serial.print(inches);
+      Serial.print("in, ");
+      Serial.print(cm);
+      Serial.print("cm");
+      Serial.println();
+      
+      delay(250);
+    }
+    ```
+
+I double, triple checked every connection and grabbed new wires in case that was the issue. After a while a directly connected it to the mcu but that also didn't work and then I gave up.
+
+![alt text](image-13.jpg)
+
+After going to Henk and reading the datasheet he said I needed to use 5 volts instead of 3.3 volts
+When I changed that connection it worked.