FreeDV Modem

FreeDV is a digital voice mode specifically for Amateur Radio HF communications. It provides wide-bandwidth, crystal-clear, noise-free audio and works with weak signals down to 5 dB under the ambient HF noise level. For us it is a game-changer: We now use it every day to run our School Amateur Radio Club Net on 7083 kHz, which we previously ran for 10 years on 7105 kHz - often putting up with barely readable and very noisy analog single-sideband signals. With FreeDV we now have our Amateur Radio (rig) connected to Hi-Fi speakers and listen all day for stations calling in without the annoying snap, crackle and pop of HF band noise. We can hear local, and many more DX stations from ZL and VK6, just like they were in the other room! When conditions on 40 m are stable we can often work stations up to 300 km away on only 100 mW PEP. So what's not to love? Well, actually, one really big thing for us: How do we use FreeDV easily when setting up our portable station at parks or summits, or safely when mobile in our car, all without having to lug around and interact with a laptop computer?

This project provides a small, "black-box" modem to easily setup your portable FreeDV station, or to use it safely (hands-free) in your car. It has no distracting screen, keyboard or mouse and runs on 12 V DC. Instead a small dash-mounted console controls everything and provides visual feedback. You just plug in a USB headset and a USB controlled Amateur Radio transceiver. You can now take FreeDV with you wherever you go!

Mobile Setup with PyFreeDV Modem, PyFreeDV Console, Headset and Uninterruptable Power Supply

Features

Safe operation while mobile:

No distracting displays or keyboards
Hands free (except for dash-mounted PTT button)

Radio frequency and modulation mode is set using the rig
Rig Audio is via USB or an external USB sound adapter
Rig PTT is via USB or an external audio VOX control
Works with USB or Bluetooth, Headset or Mic and Speaker
FreeDV Reports are uploaded via WiFi a Smart-Phone Hotspot
FreeDV Reported Frequency is obtained from the rig or the configuration file
FreeDV Reports can be monitored on a Smart-Phone Web Browser
Automatic start-up: 65 second start-up time
Shut-down button with green 12V DC power indicator: 15 second shut-down time
Regulated 5.1 V USB Power for the Raspberry Pi prevents "Low Voltage Warning" and CPU throttling
Uninterruptible Power Supply (optional) keeps PyFreeDV Modem alive when the engine is off and charges when the engine is on
Fused, 12 V power cable with in-line power switch (optional)

Hardware Setup

This project uses the following hardware:

A Raspberry Pi 3B+ (or later model)
A Raspberry Pi 3B+ Enclosure
A 32 MB micro SDHC card
A USB Headset
A PyFreeDV Dash-Mounted Control Console, requiring the following parts and tools:

An Amidon FT-140/43 ferrite toroid for RFI suppression, if necessary
A USB power adapter; or

1 - XL4015 Step-Down DC/DC Converter

An optional Uninterruptible Power Supply:

2 - XL4015 Step-Down DC/DC Converters
2 - 1N5822 3A Schottky Diodes
2500 mAh, 9.6 V NiMH Battery Pack (8 - AA cells)
Enclosure, veroboard, cable gland, toggle switch

FreeDV Console Wiring

Prepare a 10-Way rainbow ribbon cable to connect between the PyFreeDV Modem and PyFreeDV dash-mounted console.

FUNCTION	PIN	PIN	FUNCTION	APPLICATION	LED VOLTAGE	LED CURRENT	LED RESISTOR	WIRE COLOUR
3.3V	1	2	5V	SHUTDOWN BUTTON LED	2.13 V	10 mA	270 R	BROWN
GPIO2	3	4	5V
GPIO3	5	6	GND
GPIO4	7	8	GPIO14	PTT BUTTON				RED
GND	9	10	GPIO15	GROUND FOR LEDS				ORANGE
GPIO17	11	12	GPIO18	RED LED	1.77 V	6 mA	270 R	YELLOW
GPIO27	13	14	GND	GREEN LED	2.35 V	6 mA	180 R	GREEN
GPIO22	15	16	GPIO23	BLUE LED	2.65 V	8 mA	82 R	BLUE
3.3V	17	18	GPIO24
GPIO10	19	20	GND
GPIO9	21	22	GPIO25
GPIO11	23	24	GPIO8
GND	25	26	GPIO7
N.C.	27	28	N.C.u
GPIO5	29	30	GND
GPIO6	31	32	GPIO12
GPIO13	33	34	GND	SHUTDOWN BUTTON				PURPLE
GPIO19	35	36	GPIO16	PTT BUTTON LED	1.77 V	10 mA	150 R	GREY
GPIO26	37	38	GPIO20	EXTRA				WHITE
GND	39	40	GPIO21	GROUND FOR BUTTONS				BLACK

Wiring Notes

Observe that the ribbon cable must thread into the Raspberry Pi enclosure of the PyFreeDV Modem and the PyFreeDV Console. First check that the cable and crimp connectors will fit through the apertures.

The blue highlighted blocks above indicate the position of the crimp sockets on the 40-pin header. The Application and columns to the right refer to those pins.

To calculate the LED resistor values use R = (V supply - V led) / I led. V supply = 5V for the Shutdown Button LED and 3.3V for all others. Choose the next highest preferred resistor value in the range.

To wire the 10-way rainbow ribbon cable to the 40-pin IDC header on the Raspberry Pi:

Do not solder the ribbon cable conductors directly to the pins
Buy an IDC Crimp Connector Kit!
Buy the correct Crimping Tool!
Separate the three sets of ribbon cable wires and shorten the centre bundle
Strip the wire ends to 2mm
Insert the wire ends into the crimp socket
Fold over the tabs with pinch-nose plyers to initially secure the wire
Crimp the socket using the Crimping Tool
Choose 1-pin, 5-pin and 4-pin housings from the kit
Insert the crimp sockets into the correct positions of the correct housing as shown above
Make sure the crimp sockets lock into the housings
Plug the ribbon cable into the 40-way IDC header on the Raspberry Pi

The IDC Crimp Connector Kit comes with both pin and socket crimp connectors. If required, you can make a disconnect in the cable as follows:

Cut the cable at the required position
Crimp pins to each wire on the PyFreeDV Console side
Crimp sockets to each wire on the Raspberry Pi side
Insert the pins and sockets into housings. You will need four, 5-way housings
Use superglue (sparingly) to glue the housings on each side of the cable together to make a single 10-way disconnect.

To wire the LED resistors:

Cut the LED resistor pigtails to 3mm long
Cut the RGB LED pigtails flush with the shortest lead (remember the RGB/Ground order)
Solder the LED resistors to the RGB LED and to the Switch LED connections

To wire the additional ground wires:

Cut black hook-up wire to 100mm long
Strip the ends to 2mm and tin them with a soldering iron
Solder a hook-up wire between the Switch LED Grounds
Thread thin heat-shrink tubing over one hook-up wire
Solder that hook-up wire between the RGB LED Ground and one Switch LED Ground

To wire the PyFreeDV Console:

Thread the ribbon cable into the enclosure
Separate and fan out the ribbon cable into three bundles 100mm long
Separate and fan out the ends of the ribbon cable 25mm long
Strip the wire ends to 2mm and tin them with a soldering iron
Thread thin heat-shrink tubing over the ends of the ribbon cable
Solder the ends of the ribbon cable to the correct components
Position and shrink the heat-shrink tubing over all exposed conductors

Connecting Crimp Sockets to the Ribbon Cable using the Crimping Tool

Connecting The Ribbon Cable to the Raspberry Pi

PiFreeDV Console

USB Power Adapter

It is a sad fact that those USB power outlets in cars (and most USB AC phone chargers for that matter) do not deliver sufficient voltage to boot up and power a Raspberry Pi without getting a "Low Voltage" alarm and causing the CPU frequency to be throttled. Instead, an elevated USB supply must be maintained between 5.1 V and 5.25 V. We always use a switch-mode regulator module to efficiently convert between 12 - 14 V car power and 5.1 V USB power. Our favourite is the XL4015 module which has a multiturn, pre-set potentiometer to set the output voltage (and often the same to set the output current limit). There are some precautions, though: A switch must be provided for the 12 V supply as the regulator has a quiescent current of 60 mA. When the regulator is first started it draws a large in-rush current and won't start if preceded by a current limiter of less than 2A.

USB Power Check

Always use the following command on a Raspberry Pi in a terminal window to check if it is or has been subject to under-voltage, temperature limits, mild CPU frequency capping or emergency CPU throttling:

vcgencmd get_throttled

It will return a hexadecimal bitmask code as follows:

• Bit 0 (0x00001): Under-voltage currently active
• Bit 1 (0x00002): ARM frequency currently capped
• Bit 2 (0x00004): Currently throttled
• Bit 3 (0x00008): Soft temperature limit currently active
• Bit 16 (0x10000): Under-voltage has occurred since last reboot
• Bit 17 (0x20000): Frequency capping has occurred since last reboot
• Bit 18 (0x40000): Throttling has occurred since last reboot
• Bit 19 (0x80000): Soft temperature limit has occurred since last reboot

The best result is 0x00000

Uninterruptable Power Supply (Optional)

An Uninterruptable Power Supply (UPS) is required if you want to protect against corruption of the Raspberry Pi's micro SDHC card in the event of an abrupt power failure. For example, turning off the car ignition switch without shutting down the PyFreeDV Modem first. The UPS may only be needed to keep the device running for a few minutes, long enough for you to remember to press the green shutdown button and then disconnect the batteries via the power toggle switch. There are many solutions for an automotive UPS, but we wanted to avoid the risks associated with charging Lithium batteries in a potentially hot car. We originally tried a 20000 mAh USB Power Bank, but it did not maintain sufficient output voltage during the boot up process. The "Under Voltage Alarm" was raised and the CPU frequency was throttled as a result.

Instead, we decided to design our own UPS. Nickel Metal Hydride (NiMH) batteries are safer than Lithium batteries. They can be charged to about 80% capacity using a simple Constant Current/Constant Voltage charging regime. They and do not need cell load-balancing. Since we were already using an XL4015 CC/CV DC/DC converter to provide 5.1V to run the Raspberry Pi, we thought we would use another one to charge a small 9.6 V (8S) 2550 mAh NiMH battery pack from the same 12V supply. The charging current was set to 0.1C = 255 mA and the charge voltage was set to 11.2 V. A low voltage-drop 1N5822 3A Schottky diode combiner circuit was used to provide an automatic changeover from the car battery supply to the UPS battery supply. The output regulator is set to 5.1 V, the minimum to avoid Raspberry Pi undervoltage alarms, and 3 A for good measure. A double-pole toggle switch simultaneously disconnects the car battery and the backup battery, preventing discharge. The following pictorial schematic diagram shows the wiring and the setting of the XL4015 potentiometers.

Uninterruptable Power Supply Pictorial Schematic

The following photo shows the general layout of the UPS. It is housed inside a plastic zippy box. Partitions are used to separate the regulators from the battery, and to hold everything in place. The 9.6 V battery pack was made from 8 AA cells. Tin tabs were spot-welded to join the adjacent cells together. It is well worth getting a battery-operated, spot-welder for this task. Absolutely do not try to directly solder to the battery terminals - They can short and may even explode. There is also an in-line 3 A fuse in the car power connector. We estimated the NiMH battery would probably power the PyFreeDV Modem for nearly three hours after the car power was switched off. So its OK to leave it running while you stop for coffee.

Uninterruptible Power Supply Wiring

Software Setup

This project uses the following free, open-source software:

Raspberry Pi Imager for Raspberry Pi OS (64-bit) Lite: A port of Debian Trixie with no desktop (516 MB download)
A FreeDV codec, called radae_headless, ported by Peter Marks VK3TPM to run without a GUI.
HAMLIB Ham Radio Control Library
Python 3.14
Our PyFreeDV Modem script:

Runs as a Linux service on power up
Maintains a system configuration file
Controls an Amateur Radio transceiver: Frequency, Mode and PTT
Controls radae_headless, the FreeDV codec
Spots activity on the FreeDV Reporter website
Provides a Press-To-Talk toggle switch GPIO interface for hands-free operation

Our PyFreeDV Modem Installer script:

Upgrades the RPi OS
Installs Linux packages and Python libraries
Compiles radae_headless
Creates a Linux boot service

WinSCP or PuTTY to configure the system using SSH over you Home WiFi network

Software Installation

Software installation requires the preparation of a micro SDHC with a fresh installation of a Raspberry Pi OS Lite (64-bit) and then installation of the PfreeDV Modem software.

The current version of the software is: PyFreeDV Modem version 1.0

Prepare a micro SDHC Card

To get started, insert a 32 GB micro SDHC Card into the PC via a USB adapter. Download and run Raspberry Pi Imager as follows:

Select Raspberry Pi OS Lite (64-bit)

Select Device - Raspberry Pi 3

Select OS Raspberry Pi OS (Other)

Select the location, time zone and keyboard layout

Select your micro SDHC card storage device

Enter the network hostname of the Raspberry Pi

Enable SSH

Enter your username and password

Enter the SSID and Wi-Fi password of your Wi-Fi Router

Confirm Write Image

Disable Raspberry Pi Connect

Review and select Write Image

Remove the micro SDHC card

Wait for the image to be written

Wait for the image to be verified

Once the micro SDHC Card has been prepared:

Power off the Raspberry Pi
Insert the micro SDHC Card into the Raspberry Pi
Power up the Raspberry Pi - It will boot up and connect to your WiFi router
Discover the IP address of the Raspberry Pi:

Log into your WiFi Router and find the list of connected stations. Look for the RPi host name; or
Use a free IP scanner such as Advanced IP Scanner. Look for the RPi host name; or
Open a terminal session, ping your WiFi network broadcast address and use Address Resolution Protocol; or

Type: ping 192.168.1.255
Type: arp -a
You will then see a list of all the IP address on your WiFi network. It's the new one!
Ping the address with the RPi powered up or down to check.

If all else fails, temporarily connect an HDMI monitor and USB keyboard:

Log in to the Raspberry Pi using your username and password
Type: ifconfig
Look for the inet address associated with the wlan0 port

Start SCP and log in to the Raspberry Pi IP address over WiFi using your credentials

Install the PyFreeDV Modem Software

Once logged in: Copy and paste, or type, the following commands in bold to download and run the installer from this website; edit the configuration file and reboot the Raspberry Pi:

curl -fLo pyfreedv.sh https://sarcnet.org/files/FreeDV/pyfreedv.sh && chmod +x pyfreedv.sh && sudo ./pyfreedv.sh

You will have to re-enter your password. The installation process will take about 15 minutes. Then:

nano /opt/freedv/pyfreedv.txt

Edit the configuration file as described here. Then:

sudo reboot

Open WinSCP

Open the PuTTY window

Configuration

Before using the software for the first time, or to make changes, you will have configure the PyFreDV Modem application as follows:

Log into the Raspberry Pi with your user credentials:

Using WinSCP or PuTTY from a remote PC over the WiFi network; or
By temporarily connecting an HDMI display and USB Keyboard

Type: pacmd list-sources | grep -e 'name:' to list the names of all the audio input devices
Type: pacmd list-sinks | grep -e 'name:' to list the names of all the audio output devices
Type: ls -l /dev/serial/by-id to list the names of all the USB serial devices.
Match your rig's serial device name to the USB port, usually shown as: -> ../../ttyUSB0
Edit the configuration file using:

The built-in WinSCP editor on a remote Windows PC; or
PuTTY on a remote Winodws PC: Type: nano /opt/freedv/pyfreedv.txt. Press CTRL-O, <ENTER>, CTRL-X when finished; or
The HDMI display and USB Keyboard: Type: nano /opt/freedv/pyfreedv.txt. Press CTRL-O, <ENTER>, CTRL-X when finished .

The default configuration file is as shown below, with comments in bold. You will have to edit the Station, Audio, Rig and FreeDV sections:

[Station]

callsign = NOCALL Your Callsign

grid_square = QF22NC Your Maidenhead locator

[Audio]

fromradio = alsa_input.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00.analog-stereo Radio RX USB Audio Device

tospeaker = alsa_output.usb-Plantronics_Plantronics_DA45-00.mono-fallback Speaker USB Audio Device

toradio = alsa_output.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00.analog-stereo Radio TX USB Audio Device

frommic = alsa_input.usb-Plantronics_Plantronics_DA45-00.mono-fallback Microphone USB Audio Device

[Rig]

model = IC7200 HAMLIB Rig Model. See here. Note1.

rigid = 3061 HAMLIB RIG ID

freq = 7083000 Last Used Frequency. Note 2.

mode = LSB Last Used Modulation Mode

hamlib = yes Use HAMLIB to Control Radio

port = /dev/ttyUSB0 USB Serial Device to Control Radio

baud = 19200 USB Serial Device Baud Rate

[Modem]

version = PyFreeDV 1.0 Modem version as sent to FreeDV Reporter. Note 3.

beep = yes Enable an audible beep on RX SYNC Start and Stop

ptt_button = 4 GPIO Port for the PTT Button

ptt_led = 19 GPIO Port for the PTT LED

red_led = 17 GPIO Port for the RGB Red LED

green_led = 27 GPIO Port for the RGB Red LED

blue_led = 22 GPIO Port for the RGB Red LED

snr_level = (0, 10, 20) SNR Level Breakpoints in Percent for Green, Purple, Blue LED Display. Note 4.

mic_level = (30, 50, 80) Mic Level Breakpoints in Percent for Green, Purple, Blue LED Display

rgb_red = (0.02, 0.0, 0.0) RGB LED Colour Ratio for Red. Note 5.

rgb_green = (0.0, 0.02, 0.0) RGB LED Colour Ratio for Green

rgb_purple = (0.05, 0.0, 0.05) RGB LED Colour Ratio for Purple

rgb_blue = (0.0, 0.0, 0.05) RGB LED Colour Ratio for Blue

[FreeDV]

mode = RADEV1 Codec Mode as sent to FreeDV Reporter

status = TX Status (TX or RX Only) as sent to FreeDV Reporter

message = PyFreeDV is Great! Message as sent to FreeDV Reporter

report = yes Use FreeDV Reporter

url = https://qso.freedv.org:443 FreeDV Reporter URL

Notes:

The PyFreeDV app automatically sets the Rig Id from the Rig Model, but the model must exactly match the name in the list.
The PyFreeDV app always starts on the frequency and mode in the configuration file, but saves any subsequent changes.
The PyFreeDV app version is set automatically by the app
The RGB LED indicates: Off = N/A, Red = Bad, Green = Good, Purple = Better and Blue = Best, according to the breakpoints shown.
The three floating-point numbers in the brackets indicate the ratio of the Red, Green and Blue LED drive level from 0.0 to 1.0. They are all set fairly low to avoid excessive glare in a vehicle at night.

Configure Mobile Internet Access

The following additional configuration is required to add a mobile phone hotspot to the PyFreeDV Modem. When you transfer the modem to the vehicle and are outside the range of the home WiFi router, the modem should connect to your mobile phone hotspot. Copy and paste, or type, the following two commands:

sudo nmcli c add con-name <NAME> ifname wlan0 type wifi ssid <SSSID> wifi-sec.key-mgmt wpa-psk wifi-sec.psk <PASSWORD>
sudo nmcli c up <NAME>

Where:

<NAME> is the name given to the new WiFi interface
<SSID> is the ssid of the mobile phone hotspot
<PASSSWORD> is the password to access the mobile phone hotspot

Configure the Audio Levels

To set the audio volume control levels for the headset and rig interfaces you have to access the ALSA sound system by typing the following commands in bold. Different devices will have different soundcard numbers and control names. So the first step is to identify them for your set up. Some devices have sub-controls, which can only be found by querying the main control. You need to identify a total of four (4) controls: The headset earphone and microphone and the rig TX and RX controls. Then you can set the levels for each control - at least within the limits shown. Start by setting all levels to 100% and then back them off if needed. When finished, make sure you store the levels.

Get the Soundcard Numbers

aplay -l | grep 'card'

card 0: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones]
card 1: DA45 [Plantronics DA45], device 0: USB Audio [USB Audio] This is our headset interface
card 2: vc4hdmi [vc4-hdmi], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
card 3: Device [USB Audio Device], device 0: USB Audio [USB Audio] This is our rig interface

Get the Control Names for each Soundcard

amixer -c1 scontrols
Simple mixer control 'Bass',0
Simple mixer control 'Treble',0
Simple mixer control 'Sidetone',0
Simple mixer control 'Headset',0          This is the name of the headset control (it has two sub-controls - see next)
amixer -c3 scontrols
Simple mixer control 'Speaker',0           This is the name of the rig's TX audio control
Simple mixer control 'Mic',0                 This is the name of the rig's RX audio control
Simple mixer control 'Auto Gain Control',0

Get the Audio Control Levels

amixer -c1 get Headset

Simple mixer control 'Headset',0
Capabilities: pvolume pvolume-joined cvolume cvolume-joined pswitch pswitch-joined cswitch cswitch-joined

Playback channels: Mono Headset Playback is the name of the headset earphone control
Capture channels: Mono Headset Capture is the name of the headset microphone control
Limits: Playback 0 - 25 Capture 0 - 4
Mono: Playback 0 [0%] [-50.00dB] [on] Capture 0 [0%] [-9.00dB] [on]

amixer -c3 get Speaker

Simple mixer control 'Speaker',0

Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 30
Mono:
Front Left: Playback 0 [0%] [-45.00dB] [on]
Front Right: Playback 0 [0%] [-45.00dB] [on]

amixer -c3 get Mic

Simple mixer control 'Mic',0

Capabilities: pvolume pvolume-joined cvolume cvolume-joined pswitch pswitch-joined cswitch cswitch-joined
Playback channels: Mono
Capture channels: Mono
Limits: Playback 0 - 14 Capture 0 - 30
Mono: Playback 0 [0%] [-12.00dB] [off] Capture 0 [0%] [-12.00dB] [on]

Set the Audio Control Levels

amixer -c1 set Headset Playback 100%               Set headset earphone level
amixer -c1 set Headset Capture 100%                Set headset microphone level
amixer -c1 set Sidetone 50%                                Set headset sidetone level to monitor your microphone level
amixer -c3 set Speaker 100%                               Set rig TX level
amixer -c3 set Mic 100%                                       Set rig RX level

Save the Audio Control Levels

sudo alsactl store Save the audio level controls

Hardware Installation

Install the rig, PyFreeDV Modem, PyFreeDV Console and the UPS or USB power adapter in the vehicle in safe locations
Connect the PyFreeDV Modem to the rig:

A USB CAT cable for rigs with inbuilt USB serial ports and sound cards; or
A USB sound adapter for transmit and receive audio; with
A USB to serial converter for CAT control; or
A VOX control in the rig for PTT control; or
A VOX adapter for PTT control
See our USB Rig Interface page for details

Connect the USB/Bluetooth audio input and output devices to the PyFreeDV Modem:

A USB microphone and a USB Speaker; or
A USB Headset; or
A Bluetooth Headset

Connect the UPS or USB Power Adapter:

Connect 12 V car power to the UPS or USB power adapter
Connect 5 V UPS or USB power adapter power to the PyFreeDV Modem using a micro USB power cable

How it works

The user creates a new RPi OS Lite (64-bit) image using RPi Imager. Together with the user's login and home WiFi access credentials. It is a headless image, meaning it has no desktop. This was chosen to reduce to CPU overhead, especially on the RPi 3B+, and since a GUI requires an additional display which would also be distracting in a mobile environment.
The user logs into the RPi and manually downloads and runs an installation script
The installation script:

Updates and upgrades the operating system
Installs the required application libraries and removes any unused libraries
Removes any previous installations
Creates a user application directory
Clones and builds the FreeDV codec, radae_headless, a port by Peter VK3TPM from his GitHub repository
Creates a Python virtual environment
Installs the required Python libraries
Downloads the PyFreeDV application script, its configuration file and a beep.wav file from this website
Enables sound and WiFi services at boot up, without any user login, since PyFreeDV requires Pulse Audio and WiFi services, which are not normally started until user login
Creates, enables and restarts a PyFreeDV service file, which automatically executes on boot
Configures a RPi GPIO shutdown pin, in /boot/firmware/config.txt, to permit an external signal to gracefully shutdown the RPi

The PyFreeDV script:

Creates a user configuration file object:

Reads the file on start up
Saves the file with updated rig frequencies and modes

Creates a radae_headless codec object to send and receive the FreeDV digital waveform:

Starts the codec as a separate thread on start up
Captures real-time output from the codec
Signals RX and TX modes to the codec

Creates a HAMLIB rig object to control an Amateur Radio transceiver:

Gets the correct HAMLIB Rig ID for the configured HAMLIB Rig Model
Connects to the rig on start up
Gets and sets rig PTT, Frequency and Mode

Creates a GPIO ptt object to provide the user with a PTT button:

Monitors the PTT button state
Sets the modem's RX or TX mode

Creates a FreeDV Reporter spot object to send operation reports to the FreeDV Reporter website:

Connects to the FreeDV Reporter website on start up
Sends Callsign, Locator, Frequency, Status and Message
Sends RX (SNR and Callsign) and TX Reports

Creates an integrated PyFreeDV modem object:

Initializes and starts the other objects
Runs a 100ms loop, polling the codec output for SYNC, EOO and TX events
Beeps in the headset on SYNC events
Spots RX mode and SNR on SYNC events
Spots Callsign on EOO events
Spots TX mode on TX events
Tries to restart the codec on disconnection of the rig
Tries to reconnect the rig on disconnection of the rig
Tries to reconnect FreeDV Reporter on disconnection of FreeDV Reporter

Operation

In-line Power switch

Press to power up the PyFreeDV Modem - Check PyFreeDV console power LED is on
Press to power down the PyFreeDV Modem after it has been shutdown - Check PyFreeDV console power LED is off

PyFreeDV console momentary press-button shutdown switch - with green power indicator

Press to shutdown PyFreeDV Modem - Wait 15 seconds, then turn off in-line power switch
Green LED off: Power off
Green LED on: Power on

PyFreeDV console press-button PTT switch - with red PTT Indicator

Press to TX Press to RX
Red LED Off: RX Mode
Red LED On: TX Mode

PyFreeDV console RGB LED indicator

LED Off: No RX signal or TX audio
Red LED: Bad. RX signal below 0 dB SNR, or TX audio below 30%
Green LED: Good. RX signal above 0 dB SNR, or TX audio above 30%
Purple LED: Better. RX signal above 10 dB SNR, or TX audio above 50%
Blue LED: Best. RX signal above 20 dB SNR, or TX audio above 80%

Beep tone on audio output device

1 Beep - On start or stop of FreeDV RX SYNC signal

Acknowledgments

Thanks to the FreeDV Team for their huge contribution to Amateur Radio HF communication.
Thanks to Peter VK3TPM for his radae_headless code.
Thanks to Anthony VK3YSA, Felix VK3FAR and Rob VK3CKY for help with development and testing