/* TMRh20 2014 - Optimized RF24 Library Fork */ /** * Example using Dynamic Payloads * * This is an example of how to use payloads of a varying (dynamic) size. */ #include #include #include #include #include using namespace std; // // Hardware configuration // Configure the appropriate pins for your connections /****************** Raspberry Pi ***********************/ RF24 radio(22,0); // CE GPIO, CSN SPI-BUS int interruptPin = 23; // GPIO pin for interrupts /**************************************************************/ // Radio pipe addresses for the 2 nodes to communicate. const uint64_t pipes[2] = { 0xF0F0F0F0E1LL, 0xF0F0F0F0D2LL }; const int min_payload_size = 4; const int max_payload_size = 32; const int payload_size_increments_by = 1; int next_payload_size = min_payload_size; char receive_payload[max_payload_size+1]; // +1 to allow room for a terminating NULL char bool role_ping_out = 1, role_pong_back = 0; bool role = 0; void intHandler(){ // // Pong back role. Receive each packet, dump it out, and send it back // if ( role == role_pong_back ) { // if there is data ready if ( radio.available() ) { // Dump the payloads until we've gotten everything uint8_t len=0; while (radio.available()) { // Fetch the payload, and see if this was the last one. len = radio.getDynamicPayloadSize(); radio.read( receive_payload, len ); // Put a zero at the end for easy printing receive_payload[len] = 0; // Spew it printf("Got payload size=%i value=%s\n\r",len,receive_payload); } // First, stop listening so we can talk radio.stopListening(); // Send the final one back. radio.write( receive_payload, len ); printf("Sent response.\n\r"); // Now, resume listening so we catch the next packets. radio.startListening(); } } } int main(int argc, char** argv){ // Print preamble: cout << "RF24/examples/pingpair_dyn/\n"; // Setup and configure rf radio radio.begin(); radio.enableDynamicPayloads(); radio.setRetries(5,15); radio.printDetails(); /********* Role chooser ***********/ printf("\n ************ Role Setup ***********\n"); string input = ""; char myChar = {0}; cout << "Choose a role: Enter 0 for receiver, 1 for transmitter (CTRL+C to exit) \n>"; getline(cin,input); if(input.length() == 1) { myChar = input[0]; if(myChar == '0'){ cout << "Role: Pong Back, awaiting transmission " << endl << endl; }else{ cout << "Role: Ping Out, starting transmission " << endl << endl; role = role_ping_out; } } /***********************************/ if ( role == role_ping_out ) { radio.openWritingPipe(pipes[0]); radio.openReadingPipe(1,pipes[1]); } else { radio.openWritingPipe(pipes[1]); radio.openReadingPipe(1,pipes[0]); radio.startListening(); } attachInterrupt(interruptPin, INT_EDGE_FALLING, intHandler); //Attach interrupt to bcm pin 23 // forever loop while (1) { if (role == role_ping_out) { // The payload will always be the same, what will change is how much of it we send. static char send_payload[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ789012"; // First, stop listening so we can talk. radio.stopListening(); // Take the time, and send it. This will block until complete printf("Now sending length %i...",next_payload_size); radio.write( send_payload, next_payload_size ); // Now, continue listening radio.startListening(); // Wait here until we get a response, or timeout unsigned long started_waiting_at = millis(); bool timeout = false; while ( ! radio.available() && ! timeout ) if (millis() - started_waiting_at > 500 ) timeout = true; // Describe the results if ( timeout ) { printf("Failed, response timed out.\n\r"); } else { // Grab the response, compare, and send to debugging spew uint8_t len = radio.getDynamicPayloadSize(); radio.read( receive_payload, len ); // Put a zero at the end for easy printing receive_payload[len] = 0; // Spew it printf("Got response size=%i value=%s\n\r",len,receive_payload); } // Update size for next time. next_payload_size += payload_size_increments_by; if ( next_payload_size > max_payload_size ) next_payload_size = min_payload_size; // Try again 1s later delay(100); } } }