Revision 8:ebec2e50d421, committed 2016-08-02

Comitter:

elwinong

Date:

Tue Aug 02 19:49:55 2016 +0000

Parent:

7:609e7bb06486

Commit message:

Arduino I2C to mDot example

Changed in this revision

diff -r 609e7bb06486 -r ebec2e50d421 main.cpp
--- a/main.cpp	Thu Nov 19 20:15:09 2015 +0000
+++ b/main.cpp	Tue Aug 02 19:49:55 2016 +0000
@@ -1,25 +1,63 @@
+/* Adafruit I2C Temp Sensor MCP9808 -> Multitech mDot -> The Things Network (TTN)
+ *
+ * This program connects the Adafruit temp sensor board MCP9808 through I2C
+ * and sends the temperature output to the The Things Network.
+ *
+ * Based on:
+ * - mDot TTN Connect Example: https://developer.mbed.org/users/ropu/code/mDot_LoRa_example_TTN_connect/rev/609e7bb06486
+ * - Adafruit MCP9808 Library: https://github.com/adafruit/Adafruit_MCP9808_Library
+ * - mbed I2C Example: https://developer.mbed.org/handbook/I2C
+ * - TTN Backend: https://www.thethingsnetwork.org/wiki/Backend/Overview
+ *
+ * Requiremens:
+ * - Multitech UDK board and mDot: https://developer.mbed.org/platforms/MTS-mDot-F411/
+ * - Adafruit MCP9809: https://learn.adafruit.com/adafruit-mcp9808-precision-i2c-temperature-sensor-guide/overview
+ * - Serial to USB like this or similar: https://www.amazon.com/Sabrent-Serial-RS-232-Converter-CB-DB9P/dp/B00IDSM6BW/ref=sr_1_5?ie=UTF8&qid=1470167137&sr=8-5&keywords=serial+usb
+ * - Default serial port baudrate is 9600
+ *
+ * Wiring:
+ * MCP9808      :       UDK
+ * - Vdd        :       - D8 3.3V
+ * - Gnd        :       - D3 GND
+ * - SCL        :       - D15
+ * - SDA        :       - D14   
+ */
+
 #include "mbed.h"
 #include "mDot.h"
 #include "MTSLog.h"
 #include <string>
 #include <vector>
 #include <algorithm>
-// these options must match the settings on your Conduit
-// TTN Keys
-static const uint8_t netowork_session_key_array[] = {0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, 0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C};
-static const uint8_t data_session_key_array[] = {0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, 0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C};
-// uncomment the following lines and edit their values to match your configuration
-//static const uint8_t network_address_array[] = {0x02, 0x01, 0xBA, 0x01}; // use yours based on http://thethingsnetwork.org/wiki/AddressSpace
+
+// TTN Keys, setup your application and get your own keys at https://www.thethingsnetwork.org/wiki/Backend/Overview 
+static const uint8_t netowork_session_key_array[] = { 0x35, 0x41, 0x32, 0x67, 0x79, 0x76, 0x49, 0x8B, 0xBE, 0x98, 0x10, 0x80, 0x76, 0xB7, 0x61, 0x8B };
+static const uint8_t data_session_key_array[] = { 0xD3, 0x6F, 0x5E, 0x66, 0x4A, 0x1B, 0xEC, 0x0C, 0x4A, 0x63, 0x8E, 0x1C, 0x2D, 0xB3, 0x18, 0xA4 };
+static const uint8_t network_address_array[] = { 0x10, 0x81, 0xDA, 0x6F };
+
 static std::vector<uint8_t> netowork_session_key (netowork_session_key_array, netowork_session_key_array + sizeof(netowork_session_key_array) / sizeof(uint8_t));
 static std::vector<uint8_t> data_session_key (data_session_key_array, data_session_key_array + sizeof(data_session_key_array) / sizeof(uint8_t));
 static std::vector<uint8_t> network_address (network_address_array, network_address_array + sizeof(network_address_array) / sizeof(uint8_t));
-static uint8_t config_frequency_sub_band = 4;
+
+static uint8_t config_frequency_sub_band = 2;
+
+// Initialize I2C
+I2C i2c(I2C_SDA , I2C_SCL ); 
+const int addr7bit = 0x18;      // 7 bit I2C address
+const int addr8bit = addr7bit << 1; // 8bit I2C address, 0x90
+
 
 int main() {
+    
+    // Declare and initialize variables
     int32_t ret;
     mDot* dot;
-    std::vector<uint8_t> data;
-    std::string data_str = "hello ropu!";
+    char cmd[2];                        // I2C command address byte 8-bit
+    char my_data[2];                    // I2C return address bytes 16-bit
+    uint16_t amb;                       // Intermediate variable
+    std::vector<uint8_t> data;          // mDot data->send variable
+    char data_str[64];                  // Intermediate conversion variable
+    uint32_t update_interval = 15000;   // TTN transmission interval (loop interval)
     
     // get a mDot handle
     dot = mDot::getInstance();
@@ -46,7 +84,6 @@
     }
     
     
-    
     // request receive confirmation of packets from the gateway
     logInfo("enabling ACKs");
     if ((ret = dot->setAck(0)) != mDot::MDOT_OK) {
@@ -70,20 +107,57 @@
         osDelay(std::max((uint32_t)1000, (uint32_t)dot->getNextTxMs()));
     }
 
-    // format data for sending to the gateway
-    for (std::string::iterator it = data_str.begin(); it != data_str.end(); it++)
-        data.push_back((uint8_t) *it);
+    while (true) {   
+            
+        // Wake temp sensor 
+        cmd[0] = 0x01;
+        cmd[1] = 0x00;
+        i2c.write(addr8bit, cmd, 2);
+        logInfo("Wake temp sensor");
 
-    while (true) {
+        // Read ambient temperature
+        cmd[0] = 0x05;     // For list of MCP9808 commands and addresses, see https://github.com/adafruit/Adafruit_MCP9808_Library/blob/master/Adafruit_MCP9808.h
+        i2c.write(addr8bit, cmd, 1);
+        i2c.read( addr8bit, my_data, 2);
+                
+        // This section is converted from Arduino version: https://github.com/adafruit/Adafruit_MCP9808_Library/blob/master/Adafruit_MCP9808.cpp
+        amb = my_data[0];
+        amb <<= 8;
+        amb |= my_data[1];
+        
+        float tmpC = float(amb & 0x0FFF);
+        tmpC /= 16.0;
+        if (amb & 0x1000) tmpC -= 256;
+        float tmpF = (tmpC * 9.0 / 5.0 + 32.0);
+        
+        logInfo("Temp = %4.2f*C \t\t %4.2f*F", tmpC, tmpF);
+        
+        // Shutdown temp sensor
+        cmd[0] = 0x00;
+        cmd[1] = 0x00;
+        i2c.write(addr8bit, cmd, 2);
+        logInfo("Shutdown temp sensor\n");
+        
+        // Empty data vector
+        data.clear();
+        
+        // Push temperature value into data array
+        sprintf(data_str, "%4.2f", tmpF);
+        for (int i = 0; i<strlen(data_str); i++)
+        {
+            data.push_back(((char*)data_str)[i]);
+        }
+                
         // send the data to the gateway
         if ((ret = dot->send(data)) != mDot::MDOT_OK) {
             logError("failed to send", ret, mDot::getReturnCodeString(ret).c_str());
         } else {
-            logInfo("successfully sent data to gateway");
+            logInfo("successfully sent data to gateway: %s", data_str);
         }
 
         // in the 868 (EU) frequency band, we need to wait until another channel is available before transmitting again
-        osDelay(std::max((uint32_t)5000, (uint32_t)dot->getNextTxMs()));
+        osDelay(std::max(update_interval, (uint32_t)dot->getNextTxMs()));
+
     }
 
     return 0;