Add sniffer application example running on Raspberry Pi

RPi/RF24/RF24.cpp

@@ -906,13 +906,13 @@ void RF24::openReadingPipe(uint8_t child, uint64_t address)
 
 /****************************************************************************/
 
-void RF24::setAddressWidth(uint8_t a_width){
-
-	if(a_width -= 2){
-		write_register(SETUP_AW,a_width%4);
-		addr_width = (a_width%4) + 2;
-	}
-
+void RF24::setAddressWidth(uint8_t a_width)
+{
+  // 2 bytes width is described as invalid in manual, but it works and is used in sniffer example application
+  if (a_width >= 2 && a_width <= 5){
+    write_register(SETUP_AW,a_width - 2);
+    addr_width = a_width;
+  }
 }
 
 /****************************************************************************/

RPi/RF24/examples/extra/Makefile

@@ -18,7 +18,7 @@ CCFLAGS=-Ofast -mfpu=vfp -mfloat-abi=hard -march=armv6zk -mtune=arm1176jzf-s
 #CCFLAGS=
 
 # define all programs
-PROGRAMS = rpi-hub scanner
+PROGRAMS = rpi-hub scanner sniffer
 
 SOURCES = ${PROGRAMS:=.cpp}
 

RPi/RF24/examples/extra/sniffer.cpp

@@ -0,0 +1,133 @@
+/*
+Copyright (C) 2014 Andrzej Bieniek <[email protected]> 
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+Sniffing implementation based on
+http://blog.cyberexplorer.me/2014/01/sniffing-and-decoding-nrf24l01-and.html
+*/
+
+#include <cstdlib>
+#include <iostream>
+#include <RF24/RF24.h>
+
+
+#define RADIO_CE_PIN    (RPI_V2_GPIO_P1_22)
+#define RADIO_CSN_PIN   (RPI_V2_GPIO_P1_24)
+RF24 radio(RADIO_CE_PIN, RADIO_CSN_PIN, BCM2835_SPI_SPEED_8MHZ);
+
+
+void setup(int channel, uint64_t rx_addr, int rx_addr_len, int payload_size, rf24_datarate_e speed) {
+	radio.begin();
+	radio.setDataRate(speed);
+	radio.setAutoAck(false);
+	radio.setChannel(channel);
+	radio.disableCRC();
+	radio.setPayloadSize(payload_size);
+	radio.setAddressWidth(rx_addr_len);
+	radio.openReadingPipe(1,rx_addr);
+	radio.stopListening();
+	radio.printDetails();
+}
+
+void run(int rx_addr_len) {
+	radio.startListening();
+	while(1) {
+		delayMicroseconds(10);
+		while (radio.available()) {
+			char buf[rx_addr_len];
+
+			radio.read(buf, rx_addr_len);
+			for(int i=0; i<rx_addr_len; i++) {
+				printf("%.2x", buf[i]);
+			}
+			printf("\n");
+		}
+	}
+	radio.stopListening();
+}
+
+
+int main(int argc, char** argv) {
+	int payload_size = 32;
+	uint64_t rx_addr = 0xaa;
+	rf24_datarate_e speed = RF24_1MBPS;
+	int channel = 0;
+	int rx_addr_len = 2;
+	int c;
+
+	while ((c = getopt (argc, argv, "a:c:l:s:p:h")) != -1) {
+		switch (c) {
+		case 'a':
+			rx_addr = strtoll(optarg, NULL, 0);
+			break;
+		case 'c':
+			channel = atoi(optarg);
+			if (channel < 0 || channel > 128) {
+				printf("error: channel %d out of range (allowed values from 0 to 128)\n", channel);
+				abort();
+			}
+			break;
+		case 'l':
+			rx_addr_len = atoi(optarg);
+			if (rx_addr_len < 2 || rx_addr_len > 5) {
+				printf("error: addr lenght %d out of range (allowed values from 2 to 5\n", rx_addr_len);
+			}
+			break;
+		case 's':
+			switch(atoi(optarg)) {
+			case 250:
+				speed = RF24_250KBPS;
+				break;
+			case 1000:
+				speed = RF24_1MBPS;
+				break;
+			case 2000:
+				speed = RF24_2MBPS;
+				break;
+			default:
+				printf("error: uknown speed %s (allowed values in kbps: 250, 1000, 2000)\n", optarg);
+				abort();
+				break;
+			}
+			break;
+		case 'p':
+			payload_size = atoi(optarg);
+			if (payload_size < 1 || payload_size > 32) {
+				printf("error: payload %d out of range (allowed values are from 1 to 32)\n", payload_size);
+				abort();
+			}
+			break;
+		case 'h':
+		case '?':
+		default:
+			printf("%s [OPTIONS]\n\n", argv[0]);
+			printf("  -a ADDRESS\t- hex address value, e.g.: -a 0x1234AB\n");
+			printf("  -l ADDR_LEN\t- address length in bytes\n");
+			printf("  -c CHANNEL\t- RF channel from 0 to 128 \n");
+			printf("  -s SPEED\t- Modulation speed in kbps: 250, 1000, 2000, e.g. -s 1000\n");
+			printf("  -p PAYLOAD_LEN\t- payload length in bytes, maximum is 32\n");
+			abort ();
+			break;
+		}
+	}
+	if (rx_addr >> (rx_addr_len * 8)) {
+		printf("error: address 0x%llx is longer than %d bytes\n", rx_addr, rx_addr_len);
+		abort();
+	}
+	setup(channel, rx_addr, rx_addr_len, payload_size, speed);
+	run(payload_size);
+	return 0;
+}