From c8e4120b3cc117b9b35cea99d519de23ecb9bad0 Mon Sep 17 00:00:00 2001
From: Philip Lampkin <plampkin@chem.wisc.edu>
Date: Wed, 30 Dec 2020 00:10:01 -0600
Subject: Wrote PR controller sketches for slave and master

---
 .../Master_Photoreactor_Controller.ino             | 40 +++++++++++++++
 .../Slave_Photoreactor_Controller.ino              | 59 ++++++++++++++++++++++
 2 files changed, 99 insertions(+)
 create mode 100644 Digital Photoreactor Controller Firmware/Master_Photoreactor_Controller/Master_Photoreactor_Controller.ino
 create mode 100644 Digital Photoreactor Controller Firmware/Slave_Photoreactor_Controller/Slave_Photoreactor_Controller.ino

diff --git a/Digital Photoreactor Controller Firmware/Master_Photoreactor_Controller/Master_Photoreactor_Controller.ino b/Digital Photoreactor Controller Firmware/Master_Photoreactor_Controller/Master_Photoreactor_Controller.ino
new file mode 100644
index 0000000..8c2ffa4
--- /dev/null
+++ b/Digital Photoreactor Controller Firmware/Master_Photoreactor_Controller/Master_Photoreactor_Controller.ino	
@@ -0,0 +1,40 @@
+////////////////////////////////////////////////////////////////////////////////////
+//       Digital Photoreactor Controller Slave Program Controlled by I2C          //
+//          Run this slave program on the Arduino Uno or Rasberry Pi.             //      
+////////////////////////////////////////////////////////////////////////////////////
+
+#include <Wire.h>
+
+#define I2C_SLAVE_ADDR  0x26            // I2C slave address (38, 0x26)
+
+void setup()
+{
+  // init the Wire object
+  Wire.begin(); 
+  
+  // wait for slave to finish any init sequence
+  delay(2000);
+}
+
+void loop()
+{
+
+  //generate buffer containing data to send via I2C
+  uint8_t buf[1];
+  buf[0] = 25;  // adjusting this byte changes fan speed. Can be adjusted from 0 to 256.
+  buf[1] = 1;  // adjusting this byte changes LED intensity. Can be adjusted from 0 to 256. 
+
+  // send buffer 
+  Wire.beginTransmission(I2C_SLAVE_ADDR);
+  Wire.write( buf, 2);
+  Wire.endTransmission();
+  
+  // delay 20 milliseconds to accomodate slave onReceive()
+  delay(20);
+
+  /////////////////////// WHY DO I NEED THIS PART?//////////////////////////
+  Wire.requestFrom(I2C_SLAVE_ADDR, 1);
+  
+  // delay 1 second so user can watch results
+  delay(1000);
+}
diff --git a/Digital Photoreactor Controller Firmware/Slave_Photoreactor_Controller/Slave_Photoreactor_Controller.ino b/Digital Photoreactor Controller Firmware/Slave_Photoreactor_Controller/Slave_Photoreactor_Controller.ino
new file mode 100644
index 0000000..8f7acbb
--- /dev/null
+++ b/Digital Photoreactor Controller Firmware/Slave_Photoreactor_Controller/Slave_Photoreactor_Controller.ino	
@@ -0,0 +1,59 @@
+////////////////////////////////////////////////////////////////////////////////////
+//       Digital Photoreactor Controller Slave Program Controlled by I2C          //
+//                    Run this slave program on the AtTiny85.                     //      
+////////////////////////////////////////////////////////////////////////////////////
+
+#include "TinyWireS.h"                  // wrapper class for I2C slave routines
+
+#define I2C_SLAVE_ADDR  0x26            // I2C slave address (38, 0x26), 
+
+uint8_t master_data[1];               // global buffer to store data sent from the master.
+uint8_t master_bytes;                  // global variable to number of bytes sent from the master.
+
+const int LEDPin = 4;                  //Arduino pin 4, pin 3 on AtTiny85 pinout
+const int FanPin = 1;                  //Arduino pin 1, pin 6 on AtTiny85 pinout
+const int BlinkPin = 3;                //Arduino pin 3, pin 2 on AtTiny85 pinout
+
+void setup()
+{
+  // initialize the TinyWireS and usiTwiSlave libraries
+  TinyWireS.begin(I2C_SLAVE_ADDR);      // init I2C Slave mode
+
+  // register the onReceive() callback function
+  TinyWireS.onReceive(receiveEvent);
+  
+  pinMode(LEDPin, OUTPUT);   // set pin for LED PWM
+  pinMode(FanPin, OUTPUT);   // set pin for Fan PWM
+  pinMode(BlinkPin, OUTPUT); // set pin to blink LED
+  
+  TCCR0B = TCCR0B & 0b11111000 | 0b001; // sets internal timer of AtTiny85 to 31250 Hz for fast PWM for controlling fan speed
+}
+
+// Gets called when the ATtiny85 receives an I2C write slave request
+void receiveEvent(uint8_t num_bytes)
+{
+  uint8_t i;
+  
+  // save the number of bytes sent from the master
+  master_bytes = num_bytes;
+
+  // store the data from the master into the data buffer
+  for (i = 0; i < master_bytes; i++)
+    master_data[i] = TinyWireS.receive();
+
+  // set LED and Fan PWM duty to random byte values recieved from the master
+  analogWrite(FanPin, master_data[0]);
+  analogWrite(LEDPin, master_data[1]);
+
+  // blink LED whenever data is successfuly recieved
+  digitalWrite(BlinkPin, HIGH);
+  delay(10);
+  digitalWrite(BlinkPin, LOW);
+  delay(10);
+
+}
+
+void loop()
+{
+  
+}
-- 
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