From dd6f9bea39d1412ed3792bb3affc477f96c5f01a Mon Sep 17 00:00:00 2001
From: rtrimana <rtrimana@uci.edu>
Date: Mon, 23 Apr 2018 10:24:37 -0700
Subject: [PATCH] Warming-up sensor, turn on WiFi/Particle, read from sensor,
 send to cloud and sleep again (~3.8s).

---
 version2/src/C/Crypto.cpp         | 12 +++++++-----
 version2/src/C/Crypto.h           |  1 +
 version2/src/C/Sensor-Arduino.ino | 22 +++++++++++-----------
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/version2/src/C/Crypto.cpp b/version2/src/C/Crypto.cpp
index b1a3cb4..b8e3896 100755
--- a/version2/src/C/Crypto.cpp
+++ b/version2/src/C/Crypto.cpp
@@ -3,17 +3,19 @@
 
 AESKey::AESKey(Array<char> *password, Array<char> *salt, int iterationCount, int keyLength) {
 
-	// Check if we get the same salt and password from EEPROM---create new ones otherwise
+	// Read the stored password and salt from EEPROM
 	char saltBuffer[SALT_LEN], pwdBuffer[PWD_LEN], keyBuffer[KEY_LEN];
 	EEPROM.get(ADDR_SALT, saltBuffer);
-	Array<char> * storedSalt = new Array<char>(saltBuffer, SALT_LEN);
 	EEPROM.get(ADDR_PWD, pwdBuffer);
+	Array<char> * storedSalt = new Array<char>(saltBuffer, SALT_LEN);
 	Array<char> * storedPwd = new Array<char>(pwdBuffer, PWD_LEN);
-	if (storedSalt->equals(salt) && storedPwd->equals(password)) { // Take key from EEPROM if match
+	// Compare the input password and salt against the stored ones
+	if (storedSalt->equals(salt) && storedPwd->equals(password)) {
+		// Take key from EEPROM if match
 		EEPROM.get(ADDR_KEY, keyBuffer);
 		key = new Array<char>(keyBuffer, KEY_LEN);
-		delay(2000);	// Delay for sensor
-	} else {	// Generate a new key if not match
+	} else {
+		// Generate a new key if not match
 		key = new Array<char>(keyLength / 8);
 		PKCS5_PBKDF2_HMAC((unsigned char *) password->internalArray(), password->length(),
 											(unsigned char *) salt->internalArray(), salt->length(),
diff --git a/version2/src/C/Crypto.h b/version2/src/C/Crypto.h
index 15931bd..29a2186 100755
--- a/version2/src/C/Crypto.h
+++ b/version2/src/C/Crypto.h
@@ -9,6 +9,7 @@
 // 1) SALT
 // 2) PASSWORD
 // 3) LEN
+// We assume that these 3 items are put adjacently in the EEPROM
 #define SALT_LEN			8		// 8 bytes
 #define PWD_LEN				12		// 12 bytes
 #define KEY_LEN				16		// 16 bytes
diff --git a/version2/src/C/Sensor-Arduino.ino b/version2/src/C/Sensor-Arduino.ino
index 5f3f10c..241d652 100644
--- a/version2/src/C/Sensor-Arduino.ino
+++ b/version2/src/C/Sensor-Arduino.ino
@@ -15,8 +15,8 @@ SYSTEM_THREAD(ENABLED)
 #define DHTTYPE 			DHT22	// DHT 22  (AM2302)
 // IoTCloud
 #define SLEEP_TIME			30		// Sleep time in seconds
-#define RETRY_SLEEP_TIME	5		// Sleep time in seconds
-#define RETRY_TIME			100000	// stop trying after 5 seconds
+#define RETRY_SLEEP_TIME	15		// Sleep time in seconds
+#define RETRY_TIME			10000	// stop trying after 10 seconds
 
 // Initialize DHT sensor for normal 16mhz Arduino
 DHT dht(DHTPIN, DHTTYPE);
@@ -54,17 +54,18 @@ void setup() {
 	//Serial.begin();
 	//Serial.print("Time begin setup: ");
 	//Serial.println(micros());
-	Particle.connect();
-	// Wait for maximum 10 seconds - sleep if WiFi is not connected
-	// Wake up and try again after 5 seconds
-	if (!waitFor(Particle.connected, RETRY_TIME))
-		System.sleep(SLEEP_MODE_DEEP, RETRY_SLEEP_TIME);
-		
-	pinMode(PWRPIN, OUTPUT);
 	// Turn on sensor
+	pinMode(PWRPIN, OUTPUT);
 	digitalWrite(PWRPIN, HIGH);
 	// Arduino DHT
 	dht.begin();
+	// Connect to WiFi
+	Particle.connect();
+	// Wait for a maximum amount of time - sleep if WiFi is not connected
+	// Wake up and try again afterwards
+	if (!waitFor(Particle.connected, RETRY_TIME))
+		System.sleep(SLEEP_MODE_DEEP, RETRY_SLEEP_TIME);
+		
 	// Prepare device key from MAC (just last 2 of 6 digits)
 	byte mac[6];
 	WiFi.macAddress(mac);
@@ -160,8 +161,7 @@ void loop() {
 
 	//Serial.print("Time end loop: ");
 	//Serial.println(micros());
-	System.sleep(SLEEP_MODE_DEEP, SLEEP_TIME);
-
 	//while(true) { }
+	System.sleep(SLEEP_MODE_DEEP, SLEEP_TIME);
 }
 
-- 
2.34.1