main.cpp

00001 #include "mbed.h"
00002 #include "nRF24L01P.h"
00003 #include <iostream>
00004 #include <string>
00005 
00006 #define TRANSFER_SIZE   8
00007 
00008 Serial pc(USBTX, USBRX); // tx, rx
00009 nRF24L01P my_nrf24l01p(p5, p6, p7, p8, p9, p10);    // mosi, miso, sck, csn, ce, irq
00010 DigitalOut myled1(LED1);
00011 DigitalOut myled2(LED2);
00012 
00013 char txData[TRANSFER_SIZE], rxData[TRANSFER_SIZE], acked[TRANSFER_SIZE], 
00014     nacked[TRANSFER_SIZE];
00015 bool ack = false;
00016 int txDataCnt = 0;
00017 int rxDataCnt = 0;
00018 
00019 void waitForAck() {
00020     //RECEIVE ACK
00021     if (my_nrf24l01p.readable()) {
00022         // ...read the data into the receive buffer
00023         rxDataCnt = my_nrf24l01p.read( NRF24L01P_PIPE_P0, rxData, sizeof(rxData));
00024         // match with ack array
00025         if(strcmp(rxData, acked)==-1) {
00026             pc.printf("ACK\n\r");
00027             ack = true;
00028         } else {
00029             pc.printf("NACK\n\r");
00030             ack = false;
00031         }
00032         rxDataCnt = 0;
00033         // Toggle LED2 (to help debug nRF24L01+ -> Host communication)
00034         myled2 = !myled2;
00035     }
00036 }
00037 
00038 void checkValid() {
00039     waitForAck();   //other code has SWITCH statement
00040     if(ack) {//if valid, wait til next ack
00041         pc.printf("valid, please wait to send again\n\r");
00042         ack = false;
00043         while(!ack) {
00044             waitForAck();
00045         }
00046         pc.printf("ready to send again\r\n");
00047     } else {//if invalid
00048         pc.printf("invalid command, send another\n\r");
00049     }   
00050 }
00051 
00052 void send() {
00053     //SEND
00054     // If we've received anything over the host serial link...
00055     if (pc.readable()) {
00056         // ...add it to the transmit buffer
00057         txData[txDataCnt++] = pc.getc();
00058         // If the transmit buffer is full
00059         if (txDataCnt >= sizeof(txData)) {
00060             // Send the transmitbuffer via the nRF24L01+
00061             my_nrf24l01p.write(NRF24L01P_PIPE_P0, txData, txDataCnt);
00062             txDataCnt = 0;
00063             pc.printf("Sent command\n\r");
00064             
00065             //wait for valid confirmation
00066             checkValid();
00067         }
00068         // Toggle LED1 (to help debug Host -> nRF24L01+ communication)
00069         myled1 = !myled1;
00070     }
00071 }
00072 
00073 int main() {
00074     //initialize the arrays recognized as ACK and NACK
00075     for(int i = 0; i < TRANSFER_SIZE; i++) {
00076         acked[i] = '0';
00077         nacked[i] = '1';
00078     }
00079     my_nrf24l01p.powerUp();
00080     // Display the (default) setup of the nRF24L01+ chip
00081     printf("\n\r--------\r\n");
00082     printf("BASE STATION\r\n");
00083     printf("Begin communications...\r\n");
00084     printf("--------\r\n");
00085     my_nrf24l01p.setTransferSize( TRANSFER_SIZE );
00086     my_nrf24l01p.setReceiveMode();
00087     my_nrf24l01p.enable();
00088 
00089     while (1) {
00090         if(!ack) {
00091             waitForAck();
00092         } else {
00093             send();
00094         }  
00095     }
00096 }