Fix a bug where arduino would crash on incorrectly sized i2c payload

README.md

@@ -0,0 +1,7 @@
+# To install on robot
+
+```
+git clone <url>
+cd lewis-crawler/crawler_software/raspberry_pi
+make install?
+```

crawler_software/arduino/crawler_slave/crawler_slave.ino

@@ -1,37 +1,63 @@
-/* Sweep
- by BARRAGAN <http://barraganstudio.com>
- This example code is in the public domain.
-
- modified 8 Nov 2013
- by Scott Fitzgerald
- http://www.arduino.cc/en/Tutorial/Sweep
-*/
+/* Crawler Slave
+ *  
+ *  This code runs on the crawler i2c network
+ *  and provides a cleaner, less CPU intensive control over PWM devices.
+ */
 
 #include <Wire.h>
 #include <Servo.h>
 
-Servo myservo;  // create servo object to control a servo
-// twelve servo objects can be created on most boards
+// This servo is used to wipe and clean the camera lens
+Servo windowWiperServo;
 
-int pos = 0;    // variable to store the servo position
+// Variables populated over i2c from master
+int id;
+int val;
 
 void setup() {
-  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
+  // For debugging
+  //Serial.begin(115200);
   
-  Wire.begin(0x8);
+  // Attach the wiper servo to pin 9
+  windowWiperServo.attach(9);
+
+  // This is the address the pi will speak to us at
+  Wire.begin(0x4);
   
   // Call receiveEvent when data received                
   Wire.onReceive(receiveEvent);
 
+  // Setup LED
+  pinMode(LED_BUILTIN, OUTPUT);
+  digitalWrite(LED_BUILTIN, LOW);
+
+  //Serial.println("Started");
 }
 
+// Just loop to keep the running code alive, and wait for events to happen.
 void loop() {
-  delay(10);
+  delay(50);
 }
 
-void receiveEvent(int howMany) {
-  while (Wire.available()) { // loop through all but the last
-    int pos = Wire.read(); // receive byte as a int
-    myservo.write(pos);
+// This method runs when we receive a message
+void receiveEvent(int n) {
+  Wire.read(); // Remove smbus trash
+  if (true) { // Dont do anything if this is not true
+    id  = Wire.read(); // ID of the servo/device to access
+    val = Wire.read(); // Value to assign
+
+    //Serial.println(id);
+    //Serial.println(val);
+  
+    switch(id) {
+      case 1:
+        windowWiperServo.write(val);
+        break;
+    }
+  }
+
+  // Prevents a bug where if bytes are left in buffer, arduino crashes.
+  while (Wire.available()) {
+    Wire.read();
   }
 }

crawler_software/raspberry_pi/crawler.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Crawler service overseer, manages running main crawler software
+After=multi-user.target
+
+[Service]
+Type=simple
+Restart=always
+ExecStart=/usr/bin/python /srv/crawler/crawler.py
+
+[Install]
+WantedBy=multi-user.target

crawler_software/raspberry_pi/tests/discordbot.py

@@ -5,18 +5,30 @@ from gps import *
 from smbus import SMBus
 import time
 
-addr = 0x8 # bus address
+addr = 0x4 # bus address
 bus = SMBus(1) # indicates /dev/ic2-1
 
 numb = 1
 
+def writeData(value):
+    byteValue = StringToBytes(value)    
+    bus.write_i2c_block_data(addr,0x00,byteValue) #first byte is 0=command byte.. just is.
+    return -1
+
+
+def StringToBytes(val):
+        retVal = []
+        for c in val:
+                retVal.append(ord(c))
+        return retVal
+
 try:
     for _x in range (0, 2):
-            for i in range(70, 130):
-                    bus.write_byte(addr, i)
+            for i in range(78, 130):
+                    writeData("WIPE-" + str(i))
                     time.sleep(0.02)
-            for i in range(130, 70, -1):
-                    bus.write_byte(addr, i)
+            for i in range(130, 78, -1):
+                    writeData("WIPE-" + str(i))
                     time.sleep(0.02)
 except OSError:
     print("Could not speak to ardujmemo")

crawler_software/raspberry_pi/tests/stack_overflow.py

@@ -0,0 +1,20 @@
+import smbus
+import time
+import struct
+
+# for RPI version 1, use bus = smbus.SMBus(0)
+bus = smbus.SMBus(1)
+
+# This is the address we setup in the Arduino Program
+address = 0x04
+
+try:
+    for _x in range (0, 2):
+            for i in range(78, 130):
+                    bus.write_i2c_block_data(address, 0, [1, i])
+                    time.sleep(0.02)
+            for i in range(130, 78, -1):
+                    bus.write_i2c_block_data(address, 0, [1, i])
+                    time.sleep(0.02)
+except OSError:
+    print("Could not speak to ardujmemo")