main.cpp

00001 #include "mbed.h"
00002 #include <string>
00003 #include <ctype.h>
00004 
00005 // E45-TTL-100 RADIO------KL25Z
00006 // AUX--------------------PTD4
00007 // M1---------------------PTA12
00008 // M0---------------------PTA4
00009 // RXD--------------------PTE22(TX)
00010 // TXD--------------------PTE23(RX)
00011 // LORA Radio Transmits @ 868 mHz
00012 // Expected range 2000m
00013 // https://quadmeup.com/wp-content/uploads/2017/09/E45-TTL-100_Datasheet_EN_v1.2.pdf
00014 
00015 Ticker timer;
00016 Serial pc(USBTX, USBRX);    // tx, rx of the pc
00017 Serial e45(PTE22, PTE23);   // tx, rx of the E45 radio
00018 
00019 InterruptIn aux(PTD4);              // AUX the E45 radio
00020 DigitalOut m1(PTA12,PullUp);        // M1 the E45 radio
00021 DigitalOut m0(PTA4, PullUp);        // M0 the E45 radio
00022 DigitalOut myled(LED_RED);          // KL25Z RED led
00023 
00024 int ping=1;      // this number bounces between radios 
00025 bool send_something_flag= 0;         // Send flag
00026 
00027 void flank_up()
00028 {
00029     myled=1;        //Rising Edge Detected
00030 }
00031 
00032 void flank_down()
00033 {
00034     myled=0;        //Falling Edge Detected
00035 }
00036 
00037 void timer_func()   // Send something every 3 seconds
00038 {
00039     send_something_flag= 1;  // Set the send Flag
00040 }
00041 
00042 int main()
00043 {
00044     int count=0;
00045     string incoming;
00046     char c;
00047 
00048     pc.baud(115200);
00049     e45.baud(9600);                         // Default for E45
00050     e45.format(8, SerialBase::None, 1);     // Default for E45
00051     pc.printf("\n\r\nE45-TTL-100 LORA\n\r");
00052 
00053     aux.rise(&flank_up);       //Service RISING EDGE Interrupt
00054     aux.fall(&flank_down);     //Service FALLING EDGE Interrupt
00055 
00056     // select mode
00057     // Transparant Transmission
00058     if (myled ==1) {        //Check ready or not
00059         while(myled==0) {   //Wait when not yet ready
00060             count++;
00061             if (count > 2000000) {  //Kill time
00062                 count=0;
00063                 pc.printf("Wait for AUX Rising edge ");
00064             }
00065         }
00066     }
00067     wait_ms(2);
00068     m0= 0;      //Set transparant mode
00069     m1= 0;      //Set transparant mode
00070     wait_ms(1);
00071 
00072     pc.printf("E45 is now ready to send and receive \n\r");
00073     timer.attach(&timer_func, 3.0);
00074 
00075     while(1) {
00076         if (ping>9999) ping=1;
00077 
00078         if (send_something_flag==1) {
00079             if (myled == 1)  {   // AUX is high (Buffer empty), send something
00080                 wait_ms(3);
00081                 ping++;          // Increase the value
00082                 e45.printf("%04d\n\r", ping);
00083                 while(myled==0) {
00084                 }
00085                 send_something_flag=0;
00086                 pc.printf("\n\rRadio has sent %04d\n\r", ping);
00087             }
00088         }
00089 
00090         if (myled == 0)  {      // AUX is low, Chars received
00091             incoming= "";     // Clear the string
00092             while(myled==0) {
00093                 if (e45.readable()) {
00094                     c=e45.getc();
00095                     if (isdigit(c))
00096                         incoming += c;
00097                 } else {            // End transmission
00098                     if (incoming.length()==4) {
00099                         ping= atoi(incoming.c_str());
00100                         pc.printf("incoming value %4d \n\r", ping);
00101                         incoming= "";   // Clear the string
00102                     }
00103                 }
00104             }
00105         }
00106     }
00107 }