Diff: main.cpp

Revision:

0:2286a98ea739

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Dec 08 22:11:23 2012 +0000
@@ -0,0 +1,129 @@
+#include "mbed.h"
+#include "nrf24l01.h"
+
+Serial pc(USBTX, USBRX); // tx, rx
+
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+DigitalIn     mode(p20);
+
+DigitalOut     nRF_CSN(p8);
+DigitalOut     nRF_CE(p11);
+DigitalIn     nRF_IRQ(p12);
+SPI                    nRF_spi(p5, p6, p7);
+
+int main() {
+    uint8_t dump[35];
+    unsigned char scratch[5];
+    pc.baud(115200);
+    pc.printf("mbed: nRF24L01 tranceiver\r\n");
+
+    #define _NRF24L01P_SPI_MAX_DATA_RATE     10000000
+    nRF_spi.frequency(_NRF24L01P_SPI_MAX_DATA_RATE/5);     // 2Mbit, 1/5th the maximum transfer rate for the SPI bus
+  nRF_spi.format(8,0);                                   // 8-bit, ClockPhase = 0, ClockPolarity = 0
+
+    //scratch[0] = 0x01;
+    //nrf24l01_write_register(nrf24l01_RF_SETUP, scratch , 1);    // -18 dbm, air rate 1 mbps
+    
+    pc.printf("Reading all registers:\r\n");
+    nrf24l01_get_all_registers(dump);
+    for(int i=0; i<sizeof(dump); i++){
+        pc.printf("0x%02x\r\n",dump[i]);
+    }
+    
+    /* "fork" */
+    if(mode){
+        // TX Mode
+        pc.printf("Set to transmitter mode p20 high\r\n");
+        //vars
+        unsigned char data; //register to hold letter sent and received
+        unsigned int count; //counter for for loop
+        // init
+        nrf24l01_initialize_debug(false, 1, true); //initialize the 24L01 to the debug configuration as TX, 1 data byte, and auto-ack enabled
+        //main program loop
+        while(1)
+        {
+            //check UART status register to see if data has been received.  if so, process
+            while(pc.readable())
+            {
+                data = pc.getc(); //get data from UART
+                nrf24l01_write_tx_payload(&data, 1, true); //transmit received char over RF
+
+                //wait until the packet has been sent or the maximum number of retries has been active
+                while(!(nrf24l01_irq_pin_active() && (nrf24l01_irq_tx_ds_active() || nrf24l01_irq_max_rt_active())));
+
+                //check to see if the maximum number of retries has been hit.  if not, wait for the RX device
+                // to send the char back.  if so, assume the packet is lost and send "*" back to UART
+                if(!nrf24l01_irq_max_rt_active())
+                {
+                    nrf24l01_irq_clear_all(); //clear all interrupts in the 24L01
+                    nrf24l01_set_as_rx(true); //change the device to an RX to get the character back from the other 24L01
+
+                    //wait a while to see if we get the data back (change the loop maximum and the lower if
+                    //  argument (should be loop maximum - 1) to lengthen or shorten this time frame
+                    for(count = 0; count < 25000; count++)
+                    {
+                        //check to see if the data has been received.  if so, get the data and exit the loop.
+                        //  if the loop is at its last count, assume the packet has been lost and set the data
+                        //  to go to the UART to "?".  If neither of these is true, keep looping.
+                        if((nrf24l01_irq_pin_active() && nrf24l01_irq_rx_dr_active()))
+                        {
+                            nrf24l01_read_rx_payload(&data, 1); //get the payload into data
+                            break;
+                        }
+                        
+                        //if loop is on its last iteration, assume packet has been lost.
+                        if(count == 24999)
+                            data = '?';
+                    }
+                    
+                    nrf24l01_irq_clear_all(); //clear interrupts again
+                    pc.printf("%c", data); //print the received data (or ? if none) to the screen
+                
+                    wait_us(130); //wait for receiver to come from standby to RX
+                    nrf24l01_set_as_tx(); //resume normal operation as a TX
+                }
+                else
+                {
+                    nrf24l01_flush_tx(); //get the unsent character out of the TX FIFO
+                    nrf24l01_irq_clear_all(); //clear all interrupts
+                    pc.printf("*"); //print "*" to the screen to show that the receiver did not receive the packet
+                }
+                                        
+                led1 = !led1; //toggle the on-board LED as visual indication that the loop has completed
+            }
+        }
+/* ########################################################################## */        
+    }else{
+        // RX Mode
+        pc.printf("Set to receiver mode p20 low\r\n");
+        unsigned char data; //register to hold letter received and sent
+        // Init
+        nrf24l01_initialize_debug(true, 1, true); //initialize the 24L01 to the debug configuration as RX, 1 data byte, and auto-ack enabled        
+        //main program loop
+        while(1)
+        {
+            //wait until a packet has been received
+            while(!(nrf24l01_irq_pin_active() && nrf24l01_irq_rx_dr_active()));
+            
+            nrf24l01_read_rx_payload(&data, 1); //read the packet into data
+            nrf24l01_irq_clear_all(); //clear all interrupts in the 24L01
+            
+            pc.putc(data);
+            wait_us(130); //wait for the other 24L01 to come from standby to RX
+            
+            nrf24l01_set_as_tx(); //change the device to a TX to send back from the other 24L01
+            nrf24l01_write_tx_payload(&data, 1, true); //transmit received char over RF
+            
+            //wait until the packet has been sent or the maximum number of retries has been reached
+            while(!(nrf24l01_irq_pin_active() && (nrf24l01_irq_tx_ds_active() || nrf24l01_irq_max_rt_active())));
+
+            nrf24l01_irq_clear_all(); //clear interrupts again
+            nrf24l01_set_as_rx(true); //resume normal operation as an RX
+
+            led1 = !led1; //toggle the on-board LED as visual indication that the loop has completed
+        }
+    }
+}