main.cpp

00001 /*
00002     STM32 Nucleo MQTT Ultrasound Demonstration
00003     Author : Sam Walsh
00004     Date: 24/10/16
00005     Platform: STM32F746ZG NUCLEO (ARM Cortex M7 @ 216MHz)
00006     
00007     Description: This code exercises the ethernet and digital IO on the F7 Nucleo
00008     by connecting to an MQTT broker automatically through the ethernet and then
00009     publishing values from a sensor (ultrasound sensor HCSR04)
00010     
00011     Although not fully tested it is publishing values from the sensor to the MQTT broker
00012     (Raspberry Pi 3 connected on a 100Mb LAN) at a rate of about 10Hz, this is limited
00013     by the timeout functionality I have added to the default HCSR04 software - it usually
00014     waits for an echo indefinitely which leads to lags in program, so I added some timeouts (10ms)
00015     to each echo to stop that. These could be tweaked to gain more time I think.
00016     
00017     I have benchmarked the Nucleo to be able to send messages to the Pi at a rate of about 16k per second 
00018     with a payload of just "0.5", it is the ultrasound limiting the speed of transfer
00019     
00020     <samuel.walsh@manchester.ac.uk>
00021 */
00022 
00023 #include "mbed.h"
00024 #include "rtos.h"
00025 #include "EthernetInterface.h"
00026 #include <stdio.h>
00027 #include "hcsr04.h"
00028 
00029 #define MQTTCLIENT_QOS2 1
00030 #include "MQTTEthernet.h"
00031 #include "MQTTClient.h"
00032 
00033 HCSR04 UltrasonicSensor_FrontLeft(D2,D3); //Trigger,Echo 
00034 HCSR04 UltrasonicSensor_FrontCentre(D4,D5); //Trigger,Echo 
00035 HCSR04 UltrasonicSensor_FrontRight(D6,D7); //Trigger,Echo 
00036 
00037 
00038 HCSR04 UltrasonicSensor_BackLeft(PG_5,PG_6); //Trigger,Echo 
00039 HCSR04 UltrasonicSensor_BackCentre(PE_0,PG_8); //Trigger,Echo 
00040 HCSR04 UltrasonicSensor_BackRight(PF_15,PF_11); //Trigger,Echo 
00041 Serial pc(USBTX, USBRX);
00042 
00043 float distance;
00044  
00045 EthernetInterface eth;
00046 
00047 DigitalOut led1(LED1);
00048 
00049 int arrivedcount = 0;
00050 
00051 //Callback function for arriving messages
00052 void messageArrived(MQTT::MessageData& md)
00053 {
00054     MQTT::Message &message = md.message;
00055     printf("\n\rMessage arrived: qos %d, retained %d, dup %d, packetid %d\n", message.qos, message.retained, message.dup, message.id);
00056     printf("\n\rPayload %.*s\n", message.payloadlen, (char*)message.payload);
00057     ++arrivedcount;
00058 }
00059 
00060 int main()
00061 {
00062     printf("\n\n*** Ethernet MQTT Demo for STM32F746ZG***\r\n");
00063     printf("Starting to connect to Ethernet\r\n");
00064     
00065     MQTTEthernet ipstack = MQTTEthernet();
00066               
00067     MQTT::Client<MQTTEthernet, Countdown> client = MQTT::Client<MQTTEthernet, Countdown>(ipstack);
00068     
00069     //This is just my MQTT broker, this could be anything//
00070     char* hostname = "192.168.1.2";
00071     int port = 1883;
00072     printf("Connecting to %s:%d\n", hostname, port);
00073     int rc = ipstack.connect(hostname, port);
00074     if (rc != 0)
00075         printf("rc from TCP connect is %d\n", rc);
00076  
00077     MQTTPacket_connectData data = MQTTPacket_connectData_initializer;  
00078          
00079     data.MQTTVersion = 3;
00080     data.clientID.cstring = "mbed-sample";
00081     data.username.cstring = "testuser";
00082     data.password.cstring = "testpassword";
00083     
00084     
00085     //Connect to broker
00086     printf("Connecting to MQTT Broker\r\n");
00087     if ((rc = client.connect(data)) != 0)
00088         printf("rc from MQTT connect is %d\n", rc);
00089     
00090 
00091     //Start building Message
00092     MQTT::Message message;
00093     // QoS 0
00094     char buf[100];
00095     message.qos = MQTT::QOS0;
00096     message.retained = false;
00097     message.dup = false;
00098     
00099     //Publish ultrasonic distance
00100     while(1)
00101     {
00102         //I have not fully benchmarked this loop but by eye it seems to be publishing sensor data about 10Hz TODO:Speed it up as much as possible and properly characterise sensor update rates
00103         distance = UltrasonicSensor_FrontLeft.distance();
00104         wait_ms(10);
00105         if(distance == 17182){
00106             //this is just 999999 error code ran through distance calc, i should change this but 
00107             printf("\n\rOut of range ->  echo timed out");
00108             distance = 99999;
00109         }
00110         else{
00111             printf("\n\rDistance is: %0.2f", distance);
00112         }
00113         
00114         sprintf(buf, "%d", int(distance));
00115         message.payload = (void*)buf;
00116         message.payloadlen = strlen(buf)+1;
00117         rc = client.publish("RobotSensors/Ultrasound/FrontLeft", message);
00118         
00119         //Read Front Centre
00120         distance = UltrasonicSensor_FrontCentre.distance();
00121         wait_ms(10);
00122         if(distance == 17182){
00123             //this is just 999999 error code ran through distance calc, i should change this but 
00124             printf("\n\rOut of range ->  echo timed out");
00125             distance = 99999;
00126         }
00127         else{
00128             printf("\n\rDistance is: %0.2f", distance);
00129         }
00130         
00131         sprintf(buf, "%d", int(distance));
00132         message.payload = (void*)buf;
00133         message.payloadlen = strlen(buf)+1;
00134         rc = client.publish("RobotSensors/Ultrasound/FrontCentre", message);
00135         
00136         //Read Front Right
00137         distance = UltrasonicSensor_FrontRight.distance();
00138         wait_ms(10);
00139         if(distance == 17182){
00140             //this is just 999999 error code ran through distance calc, i should change this but 
00141             printf("\n\rOut of range ->  echo timed out");
00142             distance = 99999;
00143         }
00144         else{
00145             printf("\n\rDistance is: %0.2f", distance);
00146         }
00147         
00148         sprintf(buf, "%d", int(distance));
00149         message.payload = (void*)buf;
00150         message.payloadlen = strlen(buf)+1;
00151         rc = client.publish("RobotSensors/Ultrasound/FrontRight", message);
00152         
00153         
00154         
00155         distance = UltrasonicSensor_BackLeft.distance();
00156         wait_ms(10);
00157         if(distance == 17182){
00158             //this is just 999999 error code ran through distance calc, i should change this but 
00159             printf("\n\rOut of range ->  echo timed out");
00160             distance = 99999;
00161         }
00162         else{
00163             printf("\n\rDistance is: %0.2f", distance);
00164         }
00165         
00166         sprintf(buf, "%d", int(distance));
00167         message.payload = (void*)buf;
00168         message.payloadlen = strlen(buf)+1;
00169         rc = client.publish("RobotSensors/Ultrasound/BackLeft", message);
00170         
00171         //Read Front Centre
00172         distance = UltrasonicSensor_BackCentre.distance();
00173         wait_ms(10);
00174         if(distance == 17182){
00175             //this is just 999999 error code ran through distance calc, i should change this but 
00176             printf("\n\rOut of range ->  echo timed out");
00177             distance = 99999;
00178         }
00179         else{
00180             printf("\n\rDistance is: %0.2f", distance);
00181         }
00182         
00183         sprintf(buf, "%d", int(distance));
00184         message.payload = (void*)buf;
00185         message.payloadlen = strlen(buf)+1;
00186         rc = client.publish("RobotSensors/Ultrasound/BackCentre", message);
00187         
00188         //Read Front Right
00189         distance = UltrasonicSensor_BackRight.distance();
00190         wait_ms(10);
00191         if(distance == 17182){
00192             //this is just 999999 error code ran through distance calc, i should change this but 
00193             printf("\n\rOut of range ->  echo timed out");
00194             distance = 99999;
00195         }
00196         else{
00197             printf("\n\rDistance is: %0.2f", distance);
00198         }
00199         
00200         sprintf(buf, "%d", int(distance));
00201         message.payload = (void*)buf;
00202         message.payloadlen = strlen(buf)+1;
00203         rc = client.publish("RobotSensors/Ultrasound/BackRight", message);
00204     }
00205     //client.yield(100);              
00206 //    if ((rc = client.unsubscribe(topic)) != 0)
00207 //        printf("rc from unsubscribe was %d\n", rc);
00208 //    
00209 //    if ((rc = client.disconnect()) != 0)
00210 //        printf("rc from disconnect was %d\n", rc);
00211 //    
00212 //    ipstack.disconnect();
00213     
00214 
00215 }