From ad3786f6999e89bc2c9222f0d488ed8c0c3b21af Mon Sep 17 00:00:00 2001
From: James Devine <devine.jd@gmail.com>
Date: Sun, 16 Oct 2016 17:05:20 +0200
Subject: [PATCH]

---
 Cosmic Pi Trigger Threshold test | 60 +++++++++++++++++++-------------
 1 file changed, 36 insertions(+), 24 deletions(-)

diff --git a/Cosmic Pi Trigger Threshold test b/Cosmic Pi Trigger Threshold test
index d657032..5189841 100644
--- a/Cosmic Pi Trigger Threshold test	
+++ b/Cosmic Pi Trigger Threshold test	
@@ -9,51 +9,63 @@
 //Hardware is more reliable than DUE's noise immunity.
 //Note the MAX5387LAUD+ doesn't support I2C readback.
 
+//detailed threshold calibration could be done, but our signal generator doesn't plug in very well.
+//using DAC would be a nice option for checking the thresholds.
+
 void setup() {
   // put your setup code here, to run once:
-  pinMode(48, OUTPUT);
-  pinMode(49, OUTPUT);
-  pinMode(35, OUTPUT);
-  pinMode(36, OUTPUT);
-  pinMode(37, OUTPUT);
-  pinMode(A1, INPUT);
-  pinMode(A2, INPUT);
-  digitalWrite(35, LOW);
-  digitalWrite(36, LOW);
-  digitalWrite(37, LOW);
-  //pinMode(38, INPUT);
-  //pinMode(39, INPUT);
-  pinMode(5, INPUT);
-  attachInterrupt(38, striga, RISING);
-  attachInterrupt(39, strigb, RISING);  
-  attachInterrupt(5, realint, RISING);
-   Wire.begin();
-   Serial.begin(9600);
-  Serial.print("Address ");
+  pinMode(48, OUTPUT); //used to inject 3.3V signals if required with jumpers
+  pinMode(49, OUTPUT); //used to inject as well
+  pinMode(35, OUTPUT); //setup for the MAX5387 - later set to 0. signal PA0
+  pinMode(36, OUTPUT);//setup for the MAX5387 - later set to 0. signal PA1
+  pinMode(37, OUTPUT);//setup for the MAX5387 - later set to 0. signal PA2
+  pinMode(A1, INPUT); //make sure the input pins are in high impedance mode
+  pinMode(A2, INPUT);//make sure the input pins are in high impedance mode
+  digitalWrite(35, LOW);//configure the address of the MAX5387 pot
+  digitalWrite(36, LOW);//configure the address of the MAX5387 pot
+  digitalWrite(37, LOW);//configure the address of the MAX5387 pot
+  //pinMode(38, INPUT); //optional high impedance mode for strigA - note forcing signal high doesn't really work.
+  //pinMode(39, INPUT);//optional high impedance mode for strigB - note forcing signal high doesn't really work.
+  pinMode(5, INPUT); //set the interrupt pin for trigger as high impedance, probably not required
+  attachInterrupt(38, striga, RISING); //interrupt on STRIGA
+  attachInterrupt(39, strigb, RISING);  //interrupt on STRIGB
+  attachInterrupt(5, realint, RISING); //interrupt on the real trigger - note rising, 
+  
+  //setup the serial for debug
+  Serial.begin(9600);
+  //setup the MAX5387 pot
+  Wire.begin();
+  Serial.print("MAX5387 Address ");
   Serial.print(0x28, HEX);
   Wire.beginTransmission(byte(0x28)); // transmit to device #112
   Wire.write(byte(B00010011));
   Wire.write(byte(0x50));// sets register pointer to echo #1 register (0x02)
   Wire.endTransmission();      // stop transmitting
-  Serial.println("threshold set to 0x80");
-  //digitalWrite(48, HIGH);
-  //digitalWrite(49, HIGH);
+  Serial.println("threshold set to 0x50"); //note that this is manually updated by the human!
 }
 
+//interrupt routine for event on STRIGA signal (channel A high)
 void striga(){
 Serial.print("a");
 }
+
+//interrupt routine for event on STRIGB signal (channel B high)
 void strigb(){
 Serial.println("b");
 }
+
+//interrupt routine for event on TRIG signal (AND output high)
 void realint(){
 Serial.println("real");
 }
+
+
 void loop() {
   // put your main code here, to run repeatedly:
-  //delay(100);
+//nothing to do here at the moment.
+//delay(100);
 
-//digitalWrite(48, HIGH);
+//digitalWrite(48, HIGH); //3.3v signal injections via pins 48 and 49 if required.
 //digitalWrite(49, HIGH);