DreamCatcher

Specs (Version 2.03)

• L-band SAW filter (1525 - 1559 MHz)
• Two-stage L-band LNA with 34dB gain
• 1 PPM TCXO
• RF bypass for tuning from 24 - 1600 MHz - use as a regular RTL SDR!
• Software switchable bias tee
• 3 USB ports
• GPIO forest
• UARTs, I2C, SPI headers (unpopulated) for driving external hardware
• Two microSD card holders - for boot and storage!
• 1 GHz CPU
• 512 MB RAM
• USB wifi dongle (based on RTL8188CUS chipset) - AP mode capable!
• Lots of LEDs!
• Switches!
• microUSB OTG
• microUSB power port
• Audio In/Out
• Kernel Version 4.10 and Uboot (2017.01) support

Setting up the OS

There are two OSs that you can use on the DreamCatcher.

Armbian

Standard ARM Linux OS based on Debian, Highly supported but does NOT have build in support for Outernet. This OS requires lots of tweaking to get up and going...

Armbian for DreamCatcher, V5.27

NOTE: The kernel in this version of Armbian cannot be updated with apt, there is an issue with the Device Trees that will brick the device. Before doing an apt upgrade, set a hold on the kernel packages like this:

sudo apt-mark hold linux-dtb-next-sunxi linux-headers-next-sunxi linux-image-next-sunxi linux-firmware-image-next-sunxi 

Skylark

Os based on Busybox is read only and has the full Outernet system ready to go. This is the one to use if you want to play with outernet with no tweaking

Skylark, for the Passive Antenna, Released May 14, 2017

Skylark, for the Active Antenna, Released June 22, 2017

Burning the image to an SD Card

A microSD greater than 4GB in size is required.

Extract the image

It is compressed using "gzip.", many common Unzipping tools on your chosen OS can un-compress these.

Linux / OSx

gunzip [filename.gz]

Windows

use 7Zip

Write the image to the SD card

the best way to burn the SD card is by using etcher here---> https://etcher.io/

Startup the DreamCatcher with Armbian Distro

1) Insert SD card into Dreamcatcher board slot marked "SD0_OS," next to LED array.

2) insert the USB Wifi Dongle, or other USB network device if you have it.

3) Optionally - connect the USB Cable to your PC with a terminal application open.

4) connect power to a USB port, or alternatively the USB cable to PC can provide power

after the bootup process you should see a "Dreamcatcher Login:" prompt

Default Username

root

Default Password

1234

Configure Wifi

To connect to a wifi network, you can use one of the following methods, SSID/password will be stored and applied automatically at next boot.

Single Command Line

nmcli d wifi connect [your_ssid] password [your_password]

nmcli d wifi connect MYSSID password IMSOSECURE

if you succeed, you should see something like:

Connection with UUID '8f820c8a-5af3-4336-8161-6f57030a7ec5' created and activated on device 'wlan1'

Simple Command line Gui

nmtui

The UI is very self explanatory.

Check the current IP

to check assigned ip use:

ifconfig

root@dreamcatcher:/etc# ifconfig
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:8 errors:0 dropped:0 overruns:0 frame:0
          TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1104 (1.0 KiB)  TX bytes:1104 (1.0 KiB)

wlan1     Link encap:Ethernet  HWaddr e8:4e:06:4b:a6:fa  
          inet addr:10.0.1.150  Bcast:10.0.1.255  Mask:255.255.255.0
          inet6 addr: fe80::ea4e:6ff:fe4b:a6fa/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:78 errors:0 dropped:0 overruns:0 frame:0
          TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:14882 (14.5 KiB)  TX bytes:4947 (4.8 KiB)

Install The RTL-SDR Libraires and Utilities

To install librtlsdr and sdr utilities like rtl_fm etc, use:

apt update; apt install rtl-sdr

(you will need to have already connected to network for this to work)

Shutting Down

Unlike Skylark, the root filesystem here is modified and is writeable, so it is important you shut this down properly:

sudo poweroff

Hardware Details

Board LEDS

Onboard LEDs can be controlled by writing to the ON/OFF Control file in SysFs. In the case of LED1/Pckts to turn on the led, write a 1 to the SYSFS Device On/Off Control.

To Turn the Led on:

echo 1 > /sys/class/leds/packet/brightness

To Turn it off:

echo 0 > /sys/class/leds/packet/brightness

LED1 / Pckts
Description	Flashes with Outernet Packets are Received
Color	Green
Default at Boot	OFF
SysFs Device	/sys/class/leds/packet
Usage	On/Off = brightness
Notes	Unused in Armbian

LED2 / Flock
Description	Satellite Lock Indicator on when satellite signal is locked
Color	Red
Default at Boot	OFF
SysFs Device	/sys/class/leds/lock
Usage	On/Off = brightness
Notes	Unused in Armbian

LED3 / SNR1
Description	SNR indicator
Color	Blue
Default at Boot	OFF
SysFs Device	/sys/class/leds/snr1
Usage	On/Off = brightness
Notes	Unused in Armbian

LED4 / SNR2
Description	SNR indicator
Color	Blue
Default at Boot	OFF
SysFs Device	/sys/class/leds/snr2
Usage	On/Off = brightness
Notes	Unused in Armbian

LED5 / SNR3
Description	SNR indicator
Color	Blue
Default at Boot	OFF
SysFs Device	/sys/class/leds/snr3
Usage	On/Off = brightness
Notes	Unused in Armbian

LED6 / SNR4
Description	SNR indicator
Color	Blue
Default at Boot	OFF
SysFs Device	/sys/class/leds/snr4
Usage	On/Off = brightness
Notes	Unused in Armbian

LED7 / USR1
Description	sdcard activity indicator. equivalent of the HDD activity light
Color	Green
Default at Boot	OFF
SysFs Device	/sys/class/leds/storage
Usage	On/Off = brightness
Notes

LED8 / USR2
Description	heartbeat: flashes when kernel is booted and working normally.
Color	Green
Default at Boot	OFF
SysFs Device	/sys/class/leds/heartbeat
Usage	On/Off = brightness
Notes	long off, N short flashes, long off, repeat, where N = 2 * Load_Average

LED9 / PWR
Description	Power: White LED, on when board is powered.
Color	White
Default at Boot	ON
SysFs Device
Usage
Notes

LED10 / AGP3
Description
Color	Red
Default at Boot
SysFs Device
Usage
Notes

LED11 / STATUS
Description
Color	Green
Default at Boot
SysFs Device
Usage
Notes

LED12 / USBH
Description	USB Hub Indicator Light, Green when active
Color	Green
Default at Boot	ON
SysFs Device	/sys/class/leds/usbhuben
Usage	On/Off = brightness
Notes	Turning this off, will disable all USB ports.

RF Ports

There are two RF ports on the DreamCatcher, they are labeled "LNA_IN" (at the corner of the board), and "LNA_BYPASS". They are SMA Type connections. To enable them you will write a 0 or a 1 to the appropriate SYSFS file location. Writing a 1 will enable it, and a 0 will disable it. if you enable one, you must disable the other;

NOTE: you must be a Superuser to control these... use "sudo su" first

Enable LNA_BYPASS

This is normally selected when you are using an external LNA, or Active Antenna

echo 1 > /sys/class/leds/rfswitch1/brightness
echo 0 > /sys/class/leds/rfswitch2/brightness

Enable LNA_IN

This would be used with a passive antenna or internal LNA

echo 0 >  /sys/class/leds/rfswitch1/brightness
echo 1 >/sys/class/leds/rfswitch2/brightness

Enable LNA_BYPASS Bias Tee

To Enable the bias tee, use the following commands

NOTE: 68 mA current limit set by R76/100k

echo 119 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio119/direction
echo 1 > /sys/class/gpio/gpio119/value

Enable Internal Audio Speaker Amplifier

sudo su
cd /sys/class/gpio
echo 114 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio114/direction
echo 1 > /sys/class/gpio/gpio114/value

Running “alsamixer”, turn up the volume (navigate with cursors, cursor up volume up) and un-mute all channels (pressing “m” key while cursor on them)

Speaker amplifier output vias near C42, C43:

Temperature Monitoring

Armbian includes a monitoring application that gives you access to some of the hardware level details... for example to determine the CPU Temp use the following command:

armbianmonitor -m

however this of little use in automated monitoring or application development.

Usage: armbianmonitor [-h] [-b] [-c $path] [-d $device] [-D] [-m] [-p] [-r] [-u]

############################################################################

 Use armbianmonitor for the following tasks:

 armbianmonitor -c /path/to/test performs disk health/performance tests
 armbianmonitor -d monitors writes to $device
 armbianmonitor -D tries to upload debug disk info to improve armbianmonitor
 armbianmonitor -m provides simple CLI monitoring
 armbianmonitor -p tries to install cpuminer for performance measurements
 armbianmonitor -r tries to install RPi-Monitor
 armbianmonitor -u tries to upload armhwinfo.log for support purposes

############################################################################

Direct access to Temp

The following returns the temperature of the CPU in Celsius

cat /sys/class/thermal/thermal_zone0/temp

Returns:

32900

This is the same as 32.9C

TODO: I want to see how the RPi-Monitor works on the DreamCatcher, i know it works on the RaspberryPi and the OrangePi

Additional Headers

SPI1
Description	Serial Peripheral Interface
MOSI	Master Output, Slave Input
MISO	Master Input, Slave Output
CS0	Slave Select
CLK	Clock
GND	Ground

SPI2
Description	Serial Peripheral Interface
MOSI	Master Output, Slave Input
MISO	Master Input, Slave Output
CS0	Slave Select
CLK	Clock
GND	Ground

TWI2
Description	Two Wire Interface (I2C)
GND	Ground
3V3	3.3 Volt
SCK	Serial Clock Line
SDA	Serial Data Line

UART1
Description	Universal Asynchronous Receiver/Transmitter
GND	Ground
RX	Receive Line
TX	Transmit
3V3	3.3 Volt

JTAG
Description	Joint Test Action Group
RESET_N	Test Reset
GND	Ground
TDO	Test Data Out
TCK	Test Clock
TMS	Test Mode Select
TDI	Test Data In
3V3	3.3 Volt

GPIO
Description	These are in not in the correct order (what IS the CORRECT order?) Use the names to identify
5V0	5.0 Volt
GNDD1
PC15/NDQ7
PC13/NDQ5
PIN17/NRE
PC3/NCE1
PC1/NALE
PC19/NDQS
PG9/LED1
PG11/USBH
PE5
PB16
PB15
PE9
PE10
PE11
PB1
3V3
GNDD
GNDD2
PC14
PC4
PC2
PC0
PB10
PG10
PE4
PE6
PE7
PE8
PB4
PB3
PB2
PB0

Test Points

P1
Description

P4
Description

P7
Description

P5
Description

P3
Description

PWRON
Description

RESET
Description

AXPGP0
Description

AXPGP1
Description

AXPGP3
Description

AXPGP2
Description

NMI_N
Description

P11
Description

P12
Description

USBH_EN
Description

USB0_DRV
Description

SPK
Description

FACTORY
Description

LCD_020
Description

LCD_021
Description

LCD_022
Description

LCD_023
Description

LCD_CLK
Description

LCD_DE
Description

LCD_HSYNC
Description

LCD_VSYNC
Description

TPY2
Description

TPY1
Description

TPX1
Description

TPX2
Description

NON_REM1
Description

SDA
Description

SCL
Description

HS
Description

Outernet Specific Applications

Outernet Overview

NOTE: Complete Outernet support is provided by the SkyLark Release above. If you just want to play with Outernet, then using that build is much easier. The details for software setup below are more more advanced Outernet usage, without needing SkyLark..

Outernet Broadcasts on L-Band satellite

Satellite Details
Satellite Name	Orbital Position	Coverage Area	Outernet Frequency
I-4 F3 Americas	98°W	North, South, and Central America, Pacific and Atlantic Oceans	1539.8725 MHz
Alphasat	25°E	Europe, Africa, Middle East, East Asia, Atlantic and Indian Oceans	1545.9400 MHz
I-4 F1 APAC	144.0°E	Asia, Australia, Pacific and Indian Oceans	1545.9525 MHz

ONDD Setup

FTP to a DreamCatcher, copy the following files off of the system... be SURE to FORCE binary transfer.

/usr/sbin/ondd(md5:207723be33f4da57bd64a6549e11e95d)
/usr/sbin/ontimeout (md5:5092f17f0152ca352799290999ba7a6c)

Create an empty conf file

/etc/ondd/ondd.conf

Create a place to place downloads

/home/downloads (or wherever)

Create a place for download cache

/home/download_cache

Run ondd with the following command:

/usr/sbin/ondd -d --pid_file /var/run/ondd.pid --cfg-gile [empty cfg file you created] -c [location for download cache] -o [location for completed downloads] -D /var/run/ondd.data --sdr-timeout-handler /usr/sbin/ontimeout

Command Help

[Skylark][outernet@outernet:/usr/sbin]$ /usr/sbin/ondd -h
00:11:21.099 [main] Unable to load config: /etc/ondd.conf (null)
Usage: ondd 
--cfg-file CONFIG_FILE override default config file location
--pid-file PID_FILE override default pid file location
--ctrl-sock SOCK_FILE override default control socket path used for ipc
--status-sock SOCK_FILE override default status report socket path - status e
--cert-file CERT_FILE override default ceritificate file location
-D SOCK_FILE data socket path to which the demodulator sends raw s
--sdr-timeout-handler script to execute if no data arrives through the date
-o PATH path to output directory where downloaded files are d
-c PATH path to cache directory where partially downloaded fd
-O PATH if specified, files which path does not begin with td
-b N set the maximum number of download completion eventsy
-d start ondd in daemon mode
-i print to stdout the current signal strength and snr,d
-V enable verbose mode
-v display ondd version info
-h display this helptext

External API Access

Skylark has 3 known access points for external api access. These APIs provide access to specific items in a JSON format. They do not require login and are enabled by default as far as we can tell (version 4.4)

getTunerStatus

This provides the tuner connection status which is the same as what is available in the ui under Tuner-->Status tab.

Access URL

http://10.0.0.1/DIRECT/getTunerStatus

The following values are provided:

getTunerStatus Values
JSON Parameter	Description	Example Value
error	Indicates by TRUE or FALSE if there was an error in processing the request	false
result	contains the complete parameter value set	(see below)

getTunerStatus "result" Parameter Values
JSON Value	Description	Example
event		"packet_received"
event_details
lock	Indicates the status of the satellite lock where: 0 = Not Locked 1 = Locked	1
freq	Frequency the receiver is tuned to.	1539.87
freq_offset	The frequency offset in Hz from the Primary frequency
set_rs
rssi	Received signal strength indication (dBm)
snr	Signal to Noise Ratio	Indicates the strength of the incoming signal to the device, must be higher than 3.0 to 4.0 for a quality locked signal
ser	Symbol Error Rate	The rate of error for the received packet stream
crc_ok	The number of packets that passed the CRC check	317628
crc_err	The number of packets that failed the CRC check	0
alg_pk_mn	This describes how much the signal stands out from the noise.	28.06
state	Indicates the current signal lock state, where: 0 = Search 1 = Signal Detect 2 = Const Lock 3 = Code Lock 4 = Frame Lock	4
transfers	This is a JSON Array that contains the current transfers in progress. Although this is usually just one item, the code clearly supports multiple simultaneous downloads	(See Below)

getTunerStatus "result" --> "Transfer" Parameter Values
JSON Value	Description	Example
carousel_id
path	File path for the download object
hash
block_count
block_received
complete

example JSON:

{
	"result": {
		"event": "packet_received",
		"event_details": "",
		"lock": 1,
		"freq": 1539.87,
		"freq_offset": -2557.35,
		"set_rs": 4200,
		"rssi": -116.74,
		"snr": 11.58,
		"ser": 0,
		"crc_ok": 317628,
		"crc_err": 0,
		"alg_pk_mn": 28.06,
		"state": 4,
		"transfers": [{
			"carousel_id": 2,
			"path": "opaks/58d9-news-pack.2017-09-05_1743.tbz2",
			"hash": "bb4d85e4e41c190780b67dc44aee2add2be413137f6aee0c197052281a8c902d",
			"block_count": 225,
			"block_received": 136,
			"complete": 0
		}, {}]
	},
	"error": false
}

Duplicating the UI Tuner Status

the UI tuner status provides some values that must be calculated from the API Values provided above.

Implementing the Tuner UI Values
UI Label	API Value(s)	Calculation
SNR (dB)	snr	snr
Lock	lock	lock? "yes" : "no"
Rssi (dBm)	rssi	rssi
APkMn Ratio	alg_pk_mn	alg_pk_mn
Frequency (MHz)	freq	freq
Freq Offset (Hz)	freq_offset	freq_offset
Symbol Error Rate (SER)	ser	ser
Packets Received	crc_ok, crc_err	crc_ok + crc_err
Valid Packets	crc_ok	crc_ok
Valid packets %	crc_ok, crc_err	round(100*crc_ok / (crc_ok + crc_err)
Packet Error Rate (PER)	crc_err, crc_ok	round(1000*crc_err/ (crc_ok + crc_err) ) / 1000
Lock State	state	0=Search, 1=Signal Detect, 2=Const Lock, 3=Code Lock, 4=Frame Lock
Transfers:	path, block_received, block_count	path + (round( 100 * block_received / block_count)) + "%"

getAPRS

This interface provides a complete listing of the received APRS messages.

Access URL

http://10.0.0.1/DIRECT/getAPRS

getTunerStatus Values
JSON Value	Description	Example
result
error

example JSON:

{
	"result": "KE7WWT-1>APMI01,TCPIP*,qAS,KE7WWT:OUTNET\n
  KE7WWT-1>APMI01,TCPIP*,qAS,KE7WWT:OUTNET\n
  KE7WWT-1>APMI01,TCPIP*,qAS,KE7WWT:OUTNET\n",
	"error": false
}

=whatsNew

provides a list of the whats new listing

Access URL

http://10.0.0.1/DIRECT/whatsNew

getTunerStatus Values
JSON Value	Description
result	Complete result set, separated by "\n" between rows
error

Example JSON:

{"result":
	"1504634234,combined.js\n
 	1504634005,Amateur Radio/APRS/APRSAT/messages-2017-09-05_17:53.txt\n
 	1504633409,News/2017-09-05.EurekAlert - Breaking News.NASA sees development of Tropical Depression 19W.html\n
 	1504633409,News/2017-09-05.EurekAlert - Breaking News.Opioid abuse can be treated successfully in primary care settings, stud.html\n
 	1504633408,News/2017-09-05.EurekAlert - Breaking News.Eating meat linked to higher risk of diabetes.html\n",
 "error":false}

ADS-B reception using dump1090

Install Updates and Base Packages

sudo apt-mark hold linux-dtb-next-sunxi linux-headers-next-sunxi linux-image-next-sunxi linux-firmware-image-next-sunxi 
sudo apt update
sudo apt upgrade
sudo apt install rtl-sdr librtlsdr-dev pkg-config build-essential
wget https://raw.githubusercontent.com/keenerd/rtl-sdr/master/rtl-sdr.rules
sudo mv rtl-sdr.rules /etc/udev/rules.d/

Reboot the DreamCatcher

sudo reboot

Install dump1090

Download and compile dump1090 (one time only):

mkdir adsb
cd adsb
git clone https://github.com/MalcolmRobb/dump1090
cd dump1090
make

Antennas

Hook-up a 1090MHz antenna, suitable for ADS-B reception to the LNA_BYPASS RF input of Dreamcatcher. You can find some good starting points here: http://discussions.flightaware.com/ads-b-flight-tracking-f21/three-easy-diy-antennas-for-beginners-t20177.html

Running dump1090

echo 1 | sudo tee /sys/class/leds/rfswitch1/brightness
echo 0 | sudo tee /sys/class/leds/rfswitch2/brightness
./dump1090 --interactive --net

NOTE: The “rfswitch1” and “rfswitch2” lines are not strictly necessary, but will not hurt anything - the Dreamcatcher Armbian image ships with the LNA bypass enabled by default.

Running dump1090 as a daemon

if you dump1090 to run in the background after a reboot, you need to set it up as a daemon.

Create a Startup script in /etc/init.d

The following is a sample startup script. This was poached from this site: http://www.satsignal.eu/raspberry-pi/dump1090.html

• Create a simple script in /etc/init.d, in my case i called it, dump1090.sh
• Cut and paste the following into the file

#!/bin/bash
### BEGIN INIT INFO
#
# Provides:		dump1090
# Required-Start:	$remote_fs
# Required-Stop:	$remote_fs
# Default-Start:	2 3 4 5
# Default-Stop:		0 1 6
# Short-Description:	dump1090 initscript

#
### END INIT INFO
## Fill in name of program here.
PROG="dump1090"
PROG_PATH="/home/pi/dump1090"
PROG_ARGS="--interactive --net --no-fix --net-ro-size 500 --net-ro-rate 5 --net-heartbeat 60 --gain -10"
PIDFILE="/var/run/dump1090.pid"

start() {
      if [ -e $PIDFILE ]; then
          ## Program is running, exit with error.
          echo "Error! $PROG is currently running!" 1>&2
          exit 1
      else
          ## Change from /dev/null to something like /var/log/$PROG if you want to save output.
          cd $PROG_PATH
          ./$PROG $PROG_ARGS 2>&1 >/dev/null &
          echo "$PROG started"
          touch $PIDFILE
      fi
}

stop() {
      if [ -e $PIDFILE ]; then
          ## Program is running, so stop it
         echo "$PROG is running"
         killall $PROG
         rm -f $PIDFILE
         echo "$PROG stopped"
      else
          ## Program is not running, exit with error.
          echo "Error! $PROG not started!" 1>&2
          exit 1
      fi
}

## Check to see if we are running as root first.
## Found at http://www.cyberciti.biz/tips/shell-root-user-check-script.html
if [ "$(id -u)" != "0" ]; then
      echo "This script must be run as root" 1>&2
      exit 1
fi

case "$1" in
      start)
          start
          exit 0
      ;;
      stop)
          stop
          exit 0
      ;;
      reload|restart|force-reload)
          stop
          start
          exit 0
      ;;
      **)
          echo "Usage: $0 {start|stop|reload}" 1>&2
          exit 1
      ;;
esac
exit 0

NOTE: You need to alter the PROG_PATH value to the location of your dump1090 application

• Set the permission to executable

  sudo chmod +x /etc/init.d/dump1090.sh

• Install to the startup directories

  sudo update-rc.d dump1090.sh defaults

• If you want to remove it later

  sudo update-rc.d -f dump1090.sh remove

• Test Start the application

  sudo /etc/init.d/dump1090.sh start

• NOTE: If you want to stop it

  sudo /etc/init.d/dump1090.sh stop

Verify that it is running

To verify that the application is running connect to the IP Address of the system and 8080 like

http://10.0.1.150:8080

you should see a map load..

Running the Dreamcatcher SDR from another System

The SDR on the dreamcatcher is connected the the CPU via USB, this connection can be changed to an external USB and the SDR can be connected to another systems USB. Doing this will prevent the SDR from being used by the dreamcatcher.

To Do this:

1. Populate USB1 connector (or just solder wires for a usb pigtail cable)
2. Remove R72 and R73 and move them to the R116 and R117 footprints.

This will disconnect the SDR from the usb hub on the DreamCatcher and route it's usb to the external cable.

Listen to FM broadcasts

Its possible to listen to standard FM broadcast radio using the Dreamcatchers SDR.

Install necessary Software

sudo apt install rtl-sdr sox

Enable sound output through the 3.5mm TRRS connector

alsamixer

Enable every column except the second and third by pressing “m” (for mute/unmute) when the column is selected. Use the keyboard left-arrow and right-arrow keys to move among the columns. For the second column, use up-arrow and down-arrow keys to adjust output volume. Be careful to not set it too high; if the column color changes to white, it has been set too high. Leave the third column muted.

You may have to reset theseAon every boot. Alternatively, you can save and restore them using: sudo /usr/sbin/alsactl store sudo /usr/sbin/alsactl restore

Connect a TRRS (tip-ring-ring-sleeve) headset cable - the kind you might use with an Android phone - to the 3.5mm connector on Dreamcatcher that is labelled “headphn”. This has 4 conductors - a “normal” set of headphones has 3.

Run this:

rtl_fm -f 104.7M -M fm -s 340k -A fast -r 32k -l 0 -E deemp | play -r 32k -t raw -e s -b 16 -c 1 -V1 -

More information about the various command line options is at the rtl_fm homepage at http://kmkeen.com/rtl-demod-guide/

Obviously, the most important one is the -f option for selecting the tuned frequency. You may also have to play around with the -s if the output is noisy. FM broadcasts tend to be quite powerful signals, and I have not needed an antenna for receiving any of the local stations, but in case of bad reception, just adding a sub-1M SMA cable at the LNA_BYPASS RF input of the Dreamcatcher should improve reception dramatically.