Moved all files to md dir

4 files changed, 0 insertions, 828 deletions

diff --git a/writeup/article.md b/writeup/article.md
deleted file mode 100644
index c198ecf..0000000
--- a/writeup/article.md
+++ /dev/null
@@ -1,183 +0,0 @@
-# RTLSDR usage
-
-# Index
-
-
-1. Setup rtlsdr
- 1.1. Get sources
- 1.2. Drivers
- 1.3. Check if works
-2. Collection of tools
-  2.1. FM
-  2.2. Spectrum diagram
-  2.3. ADSB
-  2.4. AFSK1200
-3. Projects where rtlsdr used
-  3.1. WebSDR
-4. Problems
-  4.1. Sync errors
-5. Links
-6. Changelog
-
-
-## 1.Setup rtlsdr
-
-
-By rtlsdr usually call RTL2832U chip based tv-tunners which
-can be used for not just recievin DVB-T frequencies but much more
-and yes price is ~$10 it mean that anyone can just buy and try
-without "loosing" money.
-
-
-### 1.1.Get sources
-
-
-Main development repository is on http://sdr.osmocom.org/trac/wiki/rtl-sdr
-on github you can find more repos with experminental 
-features (https://github.com/keenerd/rtl-sdr).
-
-Getting sources from git:
-```
-  git clone git://git.osmocom.org/rtl-sdr.git
-```
-I prefer using plain binaries without any kind of installation. Just
-compile and use binary without any troubles.
-Build:
-```bash
-  cmake .
-  make
-```
-All binaries is in src dir
-
-
-### 1.2.Drivers
-
-
-Linux kernel have some drivers for rtlsdr stick and DVB-T. When you will plug
-rtlsdr then kernel probably will load DVB-T drivers and you will not able
-to use you rtlsdr for sdr. Way yo fix is it add some drivers to black list and
-next time when you will plug rtlsdr this drivers will not be loaded.
-
-Check if rtlsdr related drivers is loaded:
-```bash
-  lsmod | grep rtl28
-```
-If there is some drivers then balcklist driver by creating file
-in */etc/modprobe.d/* with content:
-```
-  blacklist dvb_usb_rtl28xxu
-```
-Next thing that could appear is permissions on rtlsdr usage when its pluged in.
-To allow everyone to use create file in */etc/udev/rules.d/* with content:
-```
-  SUBSYSTEM=="usb", ATTRS{idVendor}=="0bda", ATTRS{idProduct}=="2838", \
-  GROUP="adm", MODE="0666", SYMLINK+="rtl_sdr"
-```
-
-### 1.3.Check if works
-
-How to test if rtlsdr works? Run one of commands:
-  rtl_test
-
-I like to run rtl_adsb as you can see there that something is recieved and
-you see that everything "works":
-  rtl_adsb
-
-There should be line by line showing up some "hex" lines. If some data is showen
-then adsb data from plains is recieved.
-
-## 2.Collection of tools  
-
-
-### 2.1.FM
-
-Get some sound trancmited from FM radio stations.
-
-```bash
-  rtl_fm -f 96.3e6 -M wbfm -s 200000 -r 48000 - | aplay -r 48k -f S16_LE
-```
-
-
-### 2.2.Spectrum diagram
-
-Scan spectrum to find some activities on different frequencies.
-Good link with all description is http://kmkeen.com/rtl-power/ . 
-Main usage of rtl_power is :
-```bash
-  rtl_power -f 76M:108M:125k -i 1 fm_stations.csv
-```
-and then draw image :
-```bash
-  heatmap.py fm_stations.csv fm_stations.png
-```
-
-### 2.3.ADSB
-
-ADS-B ( Automatic dependent surveillance broadcast ) in simple words airplain
-geoposition, speed, height and flight number broadcasting. You can recieve
-this data and see how many plains is around and sometimes flight number.
-
-rtlsdr have default one rtl_adsb programm but it shows only recieved data,
-without any decoding. Here is dump1090 specifically for rtlsdr and nothing
-more:
-
-  https://github.com/antirez/dump1090
-
-description howto install could be found also here
-
-  http://www.satsignal.eu/raspberry-pi/dump1090.html
-
-Using in interactive mode with height in metrs:
-```bash
-  dump1090 --interactive --metric
-```
-Output:
-
-```
-  Hex    Flight   Altitude  Speed   Lat       Lon       Track  Messages Seen .  
-  ------------------------------------------------------------------------------
-  71be01          10052     1009    36.434    33.544    45    9         1 sec
-  424913 SDM6329  10966     711     36.440    33.405    221   65        0 sec
-```
-
-
-### 2.4.AFSK1200
-
-Gqrx is graphical SDR software where you can travel across frequencies
-and in real time search for some transmission.
-
-  http://gqrx.dk/
-
-It have builtin AFSK1200 demodulator or in simple words ham radio packets.
-And you could try to see what people sending in tex around the world.
-
-## 3.Projects where rtlsdr used  
-
-### 3.1.WebSDR
-
-WebSDR probably best site where you can go and click on some radio reciever 
-and liste what happends in some particular country. WebSDR site contains
-about 80 radio recievers around the world that can be accessed trought web
-interface. 
-  http://websdr.org/
-
-If you whant setup your own radio reciever read FAQ, prepare mail and send mail
-after that you could recieve precompiled websdr software with is easy
-to setup with rtlsdr stick.
-
-## 4.Problems 
-
-### 4.1.Sync errors
-
-Once there was sync error when was trying to use rtl_test or rtl_adsb.
-To fix that changes for better quality usb cable.
-
-# 5.Links
-
-1. [http://kmkeen.com/rtl-demod-guide/](http://kmkeen.com/rtl-demod-guide/)
-2. http://kmkeen.com/rtl-power/
-3. http://sdr.osmocom.org/trac/wiki/rtl-sdr
-4. http://www.rtl-sdr.com/
-5. https://github.com/antirez/dump1090
-6. http://gqrx.dk
-
diff --git a/writeup/article1.md b/writeup/article1.md
deleted file mode 100644
index 4995b15..0000000
--- a/writeup/article1.md
+++ /dev/null
@@ -1,462 +0,0 @@
-<pre>
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                                RTLSDR usage                                  +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                                    INDEX                                     +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
- 1. Setup rtlsdr
-   1.1. Get sources
-   1.2. Drivers
-   1.3. Check if works
- 2. Collection of tools
-   2.1. FM
-   2.2. Spectrum diagram
-   2.3. ADSB
-   2.4. AFSK1200
- 3. Projects where rtlsdr used
-   3.1. WebSDR
- 4. Problems
-   4.1. Sync errors
- 5. Links
- 6. Changelog
-
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                               1.Setup rtlsdr                                 +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-
-By rtlsdr usually call RTL2832U chip based tv-tunners which
-can be used for not just recievin DVB-T frequencies but much more
-and yes price is ~$10 it mean that anyone can just buy and try
-without "loosing" money.
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-1.1.Get sources
-
-
-Main development repository is on http://sdr.osmocom.org/trac/wiki/rtl-sdr
-on github you can find more repos with experminental 
-features (https://github.com/keenerd/rtl-sdr).
-
-Getting sources from git:
-  git clone git://git.osmocom.org/rtl-sdr.git
-
-I prefer using plain binaries without any kind of installation. Just
-compile and use binary without any troubles.
-Build:
-  cmake .
-  make
-
-All binaries is in src dir
-
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-1.2.Drivers
-
-
-Linux kernel have some drivers for rtlsdr stick and DVB-T. When you will plug
-rtlsdr then kernel probably will load DVB-T drivers and you will not able
-to use you rtlsdr for sdr. Way yo fix is it add some drivers to black list and
-next time when you will plug rtlsdr this drivers will not be loaded.
-
-Check if rtlsdr related drivers is loaded:
-  lsmod | grep rtl28
-
-If there is some drivers then balcklist driver by creating file
-in /etc/modprobe.d/ with content:
-  blacklist dvb_usb_rtl28xxu
-
-Next thing that could appear is permissions on rtlsdr usage when its pluged in.
-To allow everyone to use create file in /etc/udev/rules.d/ with content:
-  SUBSYSTEM=="usb", ATTRS{idVendor}=="0bda", ATTRS{idProduct}=="2838", \
-  GROUP="adm", MODE="0666", SYMLINK+="rtl_sdr"
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-1.3.Check if works
-
-How to test if rtlsdr works? Run one of commands:
-  rtl_test
-
-I like to run rtl_adsb as you can see there that something is recieved and
-you see that everything "works":
-  rtl_adsb
-
-There should be line by line showing up some "hex" lines. If some data is showen
-then adsb data from plains is recieved.
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                            2.Collection of tools                             +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-2.1.FM
-
-Get some sound trancmited from FM radio stations.
-
-  rtl_fm -f 96.3e6 -M wbfm -s 200000 -r 48000 - | aplay -r 48k -f S16_LE
-
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-2.2.Spectrum diagram
-
-Scan spectrum to find some activities on different frequencies.
-Good link with all description is http://kmkeen.com/rtl-power/ . 
-Main usage of rtl_power is :
-
-  rtl_power -f 76M:108M:125k -i 1 fm_stations.csv
-
-and then draw image :
-
-  heatmap.py fm_stations.csv fm_stations.png
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-2.3.ADSB
-
-ADS-B ( Automatic dependent surveillance broadcast ) in simple words airplain
-geoposition, speed, height and flight number broadcasting. You can recieve
-this data and see how many plains is around and sometimes flight number.
-
-rtlsdr have default one rtl_adsb programm but it shows only recieved data,
-without any decoding. Here is dump1090 specifically for rtlsdr and nothing
-more:
-
-  https://github.com/antirez/dump1090
-
-description howto install could be found also here
-
-  http://www.satsignal.eu/raspberry-pi/dump1090.html
-
-Using in interactive mode with height in metrs:
-  
-  dump1090 --interactive --metric
-
-Output:
-
-  Hex    Flight   Altitude  Speed   Lat       Lon       Track  Messages Seen .  
-  ------------------------------------------------------------------------------
-  71be01          10052     1009    36.434    33.544    45    9         1 sec
-  424913 SDM6329  10966     711     36.440    33.405    221   65        0 sec
-
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-2.4.AFSK1200
-
-Gqrx is graphical SDR software where you can travel across frequencies
-and in real time search for some transmission.
-
-  http://gqrx.dk/
-
-It have builtin AFSK1200 demodulator or in simple words ham radio packets.
-And you could try to see what people sending in tex around the world.
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                        3.Projects where rtlsdr used                          +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-3.1.WebSDR
-
-WebSDR probably best site where you can go and click on some radio reciever 
-and liste what happends in some particular country. WebSDR site contains
-about 80 radio recievers around the world that can be accessed trought web
-interface. 
-  http://websdr.org/
-
-If you whant setup your own radio reciever read FAQ, prepare mail and send mail
-after that you could recieve precompiled websdr software with is easy
-to setup with rtlsdr stick.
-
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                                 4.Problems                                   +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-4.1.Sync errors
-
-Once there was sync error when was trying to use rtl_test or rtl_adsb.
-To fix that changes for better quality usb cable.
-
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-+                                   5.Links                                    +
-++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-[1] http://kmkeen.com/rtl-demod-guide/
-[2] http://kmkeen.com/rtl-power/
-[3] http://sdr.osmocom.org/trac/wiki/rtl-sdr
-[4] http://www.rtl-sdr.com/
-[5] https://github.com/antirez/dump1090
-[6] http://gqrx.dk
-</pre>
-
-```c
-
-#include <stdint.h>
-#include <arpa/inet.h>
-#include <stdio.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <fcntl.h>
-#include <string.h>
-#include <unistd.h>
-#include <stdlib.h>
-#define _GNU_SOURCE
-#include <getopt.h>
-
-
-struct ihex_binrec {
-	struct ihex_binrec *next; /* not part of the real data structure */
-        uint32_t addr;
-        uint16_t len;
-        uint8_t data[];
-};
-
-/**
- * nybble/hex are little helpers to parse hexadecimal numbers to a byte value
- **/
-static uint8_t nybble(const uint8_t n)
-{
-       if      (n >= '0' && n <= '9') return n - '0';
-       else if (n >= 'A' && n <= 'F') return n - ('A' - 10);
-       else if (n >= 'a' && n <= 'f') return n - ('a' - 10);
-       return 0;
-}
-
-static uint8_t hex(const uint8_t *data, uint8_t *crc)
-{
-       uint8_t val = (nybble(data[0]) << 4) | nybble(data[1]);
-       *crc += val;
-       return val;
-}
-
-static int process_ihex(uint8_t *data, ssize_t size);
-static void file_record(struct ihex_binrec *record);
-static int output_records(int outfd);
-
-static int sort_records = 0;
-static int wide_records = 0;
-static int include_jump = 0;
-
-static int usage(void)
-{
-	fprintf(stderr, "ihex2fw: Convert ihex files into binary "
-		"representation for use by Linux kernel\n");
-	fprintf(stderr, "usage: ihex2fw [<options>] <src.HEX> <dst.fw>\n");
-	fprintf(stderr, "       -w: wide records (16-bit length)\n");
-	fprintf(stderr, "       -s: sort records by address\n");
-	fprintf(stderr, "       -j: include records for CS:IP/EIP address\n");
-	return 1;
-}
-
-int main(int argc, char **argv)
-{
-	int infd, outfd;
-	struct stat st;
-	uint8_t *data;
-	int opt;
-
-	while ((opt = getopt(argc, argv, "wsj")) != -1) {
-		switch (opt) {
-		case 'w':
-			wide_records = 1;
-			break;
-		case 's':
-			sort_records = 1;
-			break;
-		case 'j':
-			include_jump = 1;
-			break;
-		default:
-			return usage();
-		}
-	}
-
-	if (optind + 2 != argc)
-		return usage();
-
-	if (!strcmp(argv[optind], "-"))
-	    infd = 0;
-	else
-		infd = open(argv[optind], O_RDONLY);
-	if (infd == -1) {
-		fprintf(stderr, "Failed to open source file: %s",
-			strerror(errno));
-		return usage();
-	}
-	if (fstat(infd, &st)) {
-		perror("stat");
-		return 1;
-	}
-	data = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, infd, 0);
-	if (data == MAP_FAILED) {
-		perror("mmap");
-		return 1;
-	}
-
-	if (!strcmp(argv[optind+1], "-"))
-	    outfd = 1;
-	else
-		outfd = open(argv[optind+1], O_TRUNC|O_CREAT|O_WRONLY, 0644);
-	if (outfd == -1) {
-		fprintf(stderr, "Failed to open destination file: %s",
-			strerror(errno));
-		return usage();
-	}
-	if (process_ihex(data, st.st_size))
-		return 1;
-
-	return output_records(outfd);
-}
-
-static int process_ihex(uint8_t *data, ssize_t size)
-{
-	struct ihex_binrec *record;
-	uint32_t offset = 0;
-	uint32_t data32;
-	uint8_t type, crc = 0, crcbyte = 0;
-	int i, j;
-	int line = 1;
-	int len;
-
-	i = 0;
-next_record:
-	/* search for the start of record character */
-	while (i < size) {
-		if (data[i] == '\n') line++;
-		if (data[i++] == ':') break;
-	}
-
-	/* Minimum record length would be about 10 characters */
-	if (i + 10 > size) {
-		fprintf(stderr, "Can't find valid record at line %d\n", line);
-		return -EINVAL;
-	}
-
-	len = hex(data + i, &crc); i += 2;
-	if (wide_records) {
-		len <<= 8;
-		len += hex(data + i, &crc); i += 2;
-	}
-	record = malloc((sizeof (*record) + len + 3) & ~3);
-	if (!record) {
-		fprintf(stderr, "out of memory for records\n");
-		return -ENOMEM;
-	}
-	memset(record, 0, (sizeof(*record) + len + 3) & ~3);
-	record->len = len;
-
-	/* now check if we have enough data to read everything */
-	if (i + 8 + (record->len * 2) > size) {
-		fprintf(stderr, "Not enough data to read complete record at line %d\n",
-			line);
-		return -EINVAL;
-	}
-
-	record->addr  = hex(data + i, &crc) << 8; i += 2;
-	record->addr |= hex(data + i, &crc); i += 2;
-	type = hex(data + i, &crc); i += 2;
-
-	for (j = 0; j < record->len; j++, i += 2)
-		record->data[j] = hex(data + i, &crc);
-
-	/* check CRC */
-	crcbyte = hex(data + i, &crc); i += 2;
-	if (crc != 0) {
-		fprintf(stderr, "CRC failure at line %d: got 0x%X, expected 0x%X\n",
-			line, crcbyte, (unsigned char)(crcbyte-crc));
-		return -EINVAL;
-	}
-
-	/* Done reading the record */
-	switch (type) {
-	case 0:
-		/* old style EOF record? */
-		if (!record->len)
-			break;
-
-		record->addr += offset;
-		file_record(record);
-		goto next_record;
-
-	case 1: /* End-Of-File Record */
-		if (record->addr || record->len) {
-			fprintf(stderr, "Bad EOF record (type 01) format at line %d",
-				line);
-			return -EINVAL;
-		}
-		break;
-
-	case 2: /* Extended Segment Address Record (HEX86) */
-	case 4: /* Extended Linear Address Record (HEX386) */
-		if (record->addr || record->len != 2) {
-			fprintf(stderr, "Bad HEX86/HEX386 record (type %02X) at line %d\n",
-				type, line);
-			return -EINVAL;
-		}
-
-		/* We shouldn't really be using the offset for HEX86 because
-		 * the wraparound case is specified quite differently. */
-		offset = record->data[0] << 8 | record->data[1];
-		offset <<= (type == 2 ? 4 : 16);
-		goto next_record;
-
-	case 3: /* Start Segment Address Record */
-	case 5: /* Start Linear Address Record */
-		if (record->addr || record->len != 4) {
-			fprintf(stderr, "Bad Start Address record (type %02X) at line %d\n",
-				type, line);
-			return -EINVAL;
-		}
-
-		memcpy(&data32, &record->data[0], sizeof(data32));
-		data32 = htonl(data32);
-		memcpy(&record->data[0], &data32, sizeof(data32));
-
-		/* These records contain the CS/IP or EIP where execution
-		 * starts. If requested output this as a record. */
-		if (include_jump)
-			file_record(record);
-		goto next_record;
-
-	default:
-		fprintf(stderr, "Unknown record (type %02X)\n", type);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static struct ihex_binrec *records;
-
-static void file_record(struct ihex_binrec *record)
-{
-	struct ihex_binrec **p = &records;
-
-	while ((*p) && (!sort_records || (*p)->addr < record->addr))
-		p = &((*p)->next);
-
-	record->next = *p;
-	*p = record;
-}
-
-static int output_records(int outfd)
-{
-	unsigned char zeroes[6] = {0, 0, 0, 0, 0, 0};
-	struct ihex_binrec *p = records;
-
-	while (p) {
-		uint16_t writelen = (p->len + 9) & ~3;
-
-		p->addr = htonl(p->addr);
-		p->len = htons(p->len);
-		if (write(outfd, &p->addr, writelen) != writelen)
-			return 1;
-		p = p->next;
-	}
-	/* EOF record is zero length, since we don't bother to represent
-	   the type field in the binary version */
-	if (write(outfd, zeroes, 6) != 6)
-		return 1;
-	return 0;
-}
-```
\ No newline at end of file
diff --git a/writeup/gdb_helper_functions.md b/writeup/gdb_helper_functions.md
deleted file mode 100644
index e69de29..0000000
--- a/writeup/gdb_helper_functions.md
+++ /dev/null
diff --git a/writeup/rtlsdr_usage.md b/writeup/rtlsdr_usage.md
deleted file mode 100644
index c198ecf..0000000
--- a/writeup/rtlsdr_usage.md
+++ /dev/null
@@ -1,183 +0,0 @@
-# RTLSDR usage
-
-# Index
-
-
-1. Setup rtlsdr
- 1.1. Get sources
- 1.2. Drivers
- 1.3. Check if works
-2. Collection of tools
-  2.1. FM
-  2.2. Spectrum diagram
-  2.3. ADSB
-  2.4. AFSK1200
-3. Projects where rtlsdr used
-  3.1. WebSDR
-4. Problems
-  4.1. Sync errors
-5. Links
-6. Changelog
-
-
-## 1.Setup rtlsdr
-
-
-By rtlsdr usually call RTL2832U chip based tv-tunners which
-can be used for not just recievin DVB-T frequencies but much more
-and yes price is ~$10 it mean that anyone can just buy and try
-without "loosing" money.
-
-
-### 1.1.Get sources
-
-
-Main development repository is on http://sdr.osmocom.org/trac/wiki/rtl-sdr
-on github you can find more repos with experminental 
-features (https://github.com/keenerd/rtl-sdr).
-
-Getting sources from git:
-```
-  git clone git://git.osmocom.org/rtl-sdr.git
-```
-I prefer using plain binaries without any kind of installation. Just
-compile and use binary without any troubles.
-Build:
-```bash
-  cmake .
-  make
-```
-All binaries is in src dir
-
-
-### 1.2.Drivers
-
-
-Linux kernel have some drivers for rtlsdr stick and DVB-T. When you will plug
-rtlsdr then kernel probably will load DVB-T drivers and you will not able
-to use you rtlsdr for sdr. Way yo fix is it add some drivers to black list and
-next time when you will plug rtlsdr this drivers will not be loaded.
-
-Check if rtlsdr related drivers is loaded:
-```bash
-  lsmod | grep rtl28
-```
-If there is some drivers then balcklist driver by creating file
-in */etc/modprobe.d/* with content:
-```
-  blacklist dvb_usb_rtl28xxu
-```
-Next thing that could appear is permissions on rtlsdr usage when its pluged in.
-To allow everyone to use create file in */etc/udev/rules.d/* with content:
-```
-  SUBSYSTEM=="usb", ATTRS{idVendor}=="0bda", ATTRS{idProduct}=="2838", \
-  GROUP="adm", MODE="0666", SYMLINK+="rtl_sdr"
-```
-
-### 1.3.Check if works
-
-How to test if rtlsdr works? Run one of commands:
-  rtl_test
-
-I like to run rtl_adsb as you can see there that something is recieved and
-you see that everything "works":
-  rtl_adsb
-
-There should be line by line showing up some "hex" lines. If some data is showen
-then adsb data from plains is recieved.
-
-## 2.Collection of tools  
-
-
-### 2.1.FM
-
-Get some sound trancmited from FM radio stations.
-
-```bash
-  rtl_fm -f 96.3e6 -M wbfm -s 200000 -r 48000 - | aplay -r 48k -f S16_LE
-```
-
-
-### 2.2.Spectrum diagram
-
-Scan spectrum to find some activities on different frequencies.
-Good link with all description is http://kmkeen.com/rtl-power/ . 
-Main usage of rtl_power is :
-```bash
-  rtl_power -f 76M:108M:125k -i 1 fm_stations.csv
-```
-and then draw image :
-```bash
-  heatmap.py fm_stations.csv fm_stations.png
-```
-
-### 2.3.ADSB
-
-ADS-B ( Automatic dependent surveillance broadcast ) in simple words airplain
-geoposition, speed, height and flight number broadcasting. You can recieve
-this data and see how many plains is around and sometimes flight number.
-
-rtlsdr have default one rtl_adsb programm but it shows only recieved data,
-without any decoding. Here is dump1090 specifically for rtlsdr and nothing
-more:
-
-  https://github.com/antirez/dump1090
-
-description howto install could be found also here
-
-  http://www.satsignal.eu/raspberry-pi/dump1090.html
-
-Using in interactive mode with height in metrs:
-```bash
-  dump1090 --interactive --metric
-```
-Output:
-
-```
-  Hex    Flight   Altitude  Speed   Lat       Lon       Track  Messages Seen .  
-  ------------------------------------------------------------------------------
-  71be01          10052     1009    36.434    33.544    45    9         1 sec
-  424913 SDM6329  10966     711     36.440    33.405    221   65        0 sec
-```
-
-
-### 2.4.AFSK1200
-
-Gqrx is graphical SDR software where you can travel across frequencies
-and in real time search for some transmission.
-
-  http://gqrx.dk/
-
-It have builtin AFSK1200 demodulator or in simple words ham radio packets.
-And you could try to see what people sending in tex around the world.
-
-## 3.Projects where rtlsdr used  
-
-### 3.1.WebSDR
-
-WebSDR probably best site where you can go and click on some radio reciever 
-and liste what happends in some particular country. WebSDR site contains
-about 80 radio recievers around the world that can be accessed trought web
-interface. 
-  http://websdr.org/
-
-If you whant setup your own radio reciever read FAQ, prepare mail and send mail
-after that you could recieve precompiled websdr software with is easy
-to setup with rtlsdr stick.
-
-## 4.Problems 
-
-### 4.1.Sync errors
-
-Once there was sync error when was trying to use rtl_test or rtl_adsb.
-To fix that changes for better quality usb cable.
-
-# 5.Links
-
-1. [http://kmkeen.com/rtl-demod-guide/](http://kmkeen.com/rtl-demod-guide/)
-2. http://kmkeen.com/rtl-power/
-3. http://sdr.osmocom.org/trac/wiki/rtl-sdr
-4. http://www.rtl-sdr.com/
-5. https://github.com/antirez/dump1090
-6. http://gqrx.dk
-