Basic transmitter-only main loop

impl/src/main.c

@@ -1,5 +1,6 @@
 #include <linux/if.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 #include <math.h>
@@ -7,7 +8,10 @@
 
 #include <liquid/liquid.h>
 
+#include <sys/poll.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <poll.h>
 
 #include "utils.h"
 #include "layer1/tx.h"
@@ -15,6 +19,10 @@
 
 #include "layer2/tundev.h"
 
+#include "sdr/sdr.h"
+
+#include "config.h"
+
 #define RESULT_CHECK(stmt) { \
 	result_t res = stmt; \
 	if(res != OK) { \
@@ -108,11 +116,65 @@ void cb_rx(rx_evt_t evt, uint8_t *packet_data, size_t packet_len)
 }
 
 
+static int debug_fd;
+
+
+#define CHUNKSIZE_BB 512
+#define CHUNKSIZE_RF (CHUNKSIZE_BB * SDR_OVERSAMPLING)
+static result_t transmit_in_chunks(sdr_ctx_t *sdr, const float complex *samples, size_t len)
+{
+	size_t transmitted = 0;
+	unsigned retry_counter = 0;
+
+	float complex rf_samples[CHUNKSIZE_RF];
+
+	while(transmitted < len) {
+		size_t to_transmit_bb = len - transmitted;
+		if(to_transmit_bb > CHUNKSIZE_BB) {
+			to_transmit_bb = CHUNKSIZE_BB;
+		}
+
+		RESULT_CHECK(sdr_baseband_to_rf(sdr, samples + transmitted, to_transmit_bb, rf_samples, CHUNKSIZE_RF));
+
+		size_t to_transmit_rf = to_transmit_bb * SDR_OVERSAMPLING;
+
+		result_t result = sdr_transmit(sdr, rf_samples, to_transmit_rf, 100000);
+
+		if(result != OK) {
+			retry_counter++;
+			fprintf(stderr, "sdr_transmit failed %d times\n", retry_counter);
+
+			if(retry_counter > 3) {
+				return result;
+			} else {
+				continue;
+			}
+		}
+
+		write(debug_fd, rf_samples, to_transmit_rf*sizeof(rf_samples[0]));
+
+		fprintf(stderr, "t");
+
+		transmitted += to_transmit_bb;
+
+		retry_counter = 0;
+	}
+
+	return OK;
+}
+
+
 int main(void)
 {
 	layer1_tx_t tx;
 	layer1_rx_t rx;
 
+	sdr_ctx_t   sdr;
+
+	bool on_air = false;
+
+	debug_fd = open("/tmp/dump.cf32", O_CREAT | O_WRONLY | O_TRUNC);
+
 	// ** Initialize **
 
 	char devname[IFNAMSIZ] = "hamnet70";
@@ -122,22 +184,36 @@ int main(void)
 		return 1;
 	}
 
+	RESULT_CHECK(sdr_init(&sdr));
+
 	RESULT_CHECK(layer1_tx_init(&tx));
 	RESULT_CHECK(layer1_rx_init(&rx, cb_rx));
 
-	// channel emulation
-	channel_cccf channel = channel_cccf_create();
-
-	float snr = 15.0f;
-	channel_cccf_add_awgn(channel, -snr, snr);
-	channel_cccf_add_carrier_offset(channel, 0.20f, 1.00f);
-	//channel_cccf_add_shadowing(channel, 1.00f, 0.1f);
-
 	// ** Process packets **
 
-	uint8_t packetbuf[2048];
+	struct pollfd pfd;
+	memset(&pfd, 0, sizeof(pfd));
+
+	pfd.fd = m_tunfd;
+	pfd.events = POLLIN;
+
+	RESULT_CHECK(sdr_start_rx(&sdr));
+
+	unsigned rx_retries = 0;
+
+	float complex zeros[1024];
+	memset(zeros, 0, sizeof(zeros));
+
 	while(m_running) {
-		int ret = read(m_tunfd, packetbuf, sizeof(packetbuf));
+		if(on_air || !layer1_rx_is_busy(&rx)) {
+			int ret = poll(&pfd, 1, 0);
+			if(ret < 0) {
+				perror("poll");
+				break;
+			} else if(ret > 0) {
+				// there is a packet to be read.
+				uint8_t packetbuf[2048];
+				ret = read(m_tunfd, packetbuf, sizeof(packetbuf));
 				if(ret < 0) {
 					perror("read");
 					break;
@@ -160,30 +236,62 @@ int main(void)
 
 				dump_array_cf(whole_burst, burst_len, 1.0f, "/tmp/tx.cpx");
 
-		// ** Apply channel distortions **
+				if(!on_air) {
-
+					RESULT_CHECK(sdr_start_tx(&sdr));
-		float complex msg_received[burst_len];
-
-		channel_cccf_execute_block(channel, whole_burst, burst_len, msg_received);
-
-		// scale the entire signal to give the AGC something to do
-		for(size_t i = 0; i < burst_len; i++) {
-			msg_received[i] *= 0.02f;
 				}
 
-		dump_array_cf(msg_received, burst_len, 1.0f, "/tmp/rx.cpx");
+				RESULT_CHECK(transmit_in_chunks(&sdr, whole_burst, burst_len));
 
+				on_air = true;
+			} else if(on_air) { // ret == 0
+				//RESULT_CHECK(sdr_start_rx(&sdr));
+				//on_air = false;
+				fprintf(stderr, "z");
+				sdr_transmit(&sdr, zeros, sizeof(zeros)/sizeof(zeros[0]), 100000);
+			}
+		}
+
+		if(!on_air) {
 			// ** Receive signal **
 
-		RESULT_CHECK(layer1_rx_process(&rx, msg_received, burst_len));
+			float complex rf_samples[CHUNKSIZE_RF];
+			float complex bb_samples[CHUNKSIZE_BB];
+
+			size_t n_rf_samples = CHUNKSIZE_RF;
+			size_t n_bb_samples;
+
+			if(sdr_receive(&sdr, rf_samples, &n_rf_samples, 100000) != OK) {
+				rx_retries++;
+				fprintf(stderr, "sdr_receive() failed %d times.\n", rx_retries);
+				if(rx_retries >= 3) {
+					break;
+				} else {
+					continue;
+				}
 			}
 
-	// ** Cleanup **
+			rx_retries = 0;
 
-	channel_cccf_destroy(channel);
+			fprintf(stderr, "r");
+
+			RESULT_CHECK(sdr_rf_to_baseband(&sdr, rf_samples, n_rf_samples, bb_samples, CHUNKSIZE_BB));
+
+			n_bb_samples = n_rf_samples / SDR_OVERSAMPLING;
+
+			RESULT_CHECK(layer1_rx_process(&rx, bb_samples, n_bb_samples));
+		} else {
+			rx_retries = 0;
+		}
+	}
+
+	close(debug_fd);
+
+	// ** Cleanup **
 
 	layer1_tx_shutdown(&tx);
 	layer1_rx_shutdown(&rx);
 
+	sdr_destroy(&sdr);
+
 	fprintf(stderr, "Done.\n");
 }