SVXLink install for the RF.Guru TRXrptr HAT (TRXrptr)

SVXLink Bookworm Image

Bookworm 64Bit Lite 2024-02-01 Image

Utilize PI-Imager to write the image to your MicroSD card! Don't use svxlink, root as a username, these are system usernames, using them will result in a broken installation !

Use the latest release of PI-Imager Github

Youtube demonstration of how to use PI-Imager on Windows 11

Youtube demonstration of how to use PI-Imager on MacOS X

It appears that the Raspberry Pi freezes after resizing the file system. Currently, after the initial boot, wait for 10 minutes, disconnect the power, and then restart. We suspect this issue is a bug and anticipate it will likely be resolved in a future release of pi-shrink.

To complete the final configuration step, SSH is required. For Linux/Mac, SSH is installed by default. Open a terminal and type ssh username@ip. However, for Windows, you'll need an additional application, such as Putty.

Youtube how to install putty on Windows 11

Ensure that you download Putty for the correct architecture; for the majority, it will be x86 64-bit.

Manual Install

HAT has been successfully trialed on both a Raspberry Pi Zero 2 W and a Raspberry Pi 4, and it is anticipated to be compatible with other models as well.

The board includes an audio card and offers the option for audio and PTT bypass functionality.
PTT operation is achieved using a compact relay with both NC and NO contacts available.
Additionally, PTT/COS-COR bypass functionality is also facilitated through a small relay with both NC and NO contacts accessible.
COS detection can be optionally configured within the voltage range of 3V to 24V.

To begin, make sure to prepare your SD card with the Raspberry Pi OS Lite as demonstrated in this (YouTube) video.

Next, access your system through SSH and execute the following commands:

Install GIT

sudo apt -y install git

Clone repostory

git clone https://github.com/Guru-RF/SVXTRXRepeater.git

Audio and Radio module installation script

cd SVXTRXRepeater
sudo bash install-trxrptr.sh 

SVXLink installation script

cd SVXTRXRepeater
sudo bash install-svxlink.sh

Simple Test

Initiating the parrot function commences upon transmitting a D1# DTMF signal.

GPIO Pins

Description of the GPIO pins

GPIO 7: Configured as an output. Set it to a high signal to deactivate the audio bypass (the audio is in bypass mode by default).
GPIO 8: Configured as an output. This pin is used for optional PTT bypass (refer to the breakout for details).
GPIO 16: Configured as an output. Utilize this pin to activate PTT for any type of PTT operation, such as using a relay.
GPIO 12: Configured as an input. This pin is used for COS (Carrier Operated Squelch) detection. Depending on your transceiver, the logic voltage can vary within the range of 3.3V to 24V.

AUDIO Pins

Description of the AUDIO pins

AUDIOOUT/RMIC corresponds to transmitting audio, which signifies audio going from the board to the repeater.
AUDIOIN/RAF corresponds to receiving audio, indicating audio traveling from the repeater to the board.
GND this is common ground, also needed for the audio in and output

PTT Pins

Description of the GPIO pins

PTTGND -> PTT Ground
PTTNO -> PTT Normaly Open
PTTNC -> PTT Normaly Closed

Custom Bypass Pins

Description of the GPIO pins

BPGND -> Bypass Ground
BPNO -> Bypass Normaly Open
BPNC -> Bypass Normaly Closed

Breakout Board Overview

The breakout board is self-explanatory. Below is a detailed explanation of its components and connections:

PTT Connections

• For most radios, you can wire PTTGND and GND together.
• If you're using a sequencer or another method to drive the PTT, the PTTGND, PTTNO, and PTTNC terminals represent the output of a relay:
  • PTTNO: Normally Open.
  • PTTNC: Normally Closed.
  • driven by GPIO 16

Audio Connections

• AUDIO IN: Connect this to the audio output of your receiver or transceiver.
• AUDIO OUT: Connect this to the audio input of your transmitter or transceiver.

Capacitors

• The capacitors on the board are used to remove bias on the audio channel. If your system has bias, remove the jumpers for the capacitors.

Audio Gain Adjustment

• If the audio gain (input/output) is too high and the DSP's volume management span is insufficient, you can remove the jumpers for the potentiometers and manually adjust the gain.

COS (Carrier Operated Switch)

• COS Input: Connect this to the COS output of your transceiver or receiver.
• Jumper Settings:
  • 3-30V: Use this position for high-current triggers.
  • 5V: Use this position for low-current triggers (sufficient for most radios).
  • If your COS output operates at a higher voltage, use the 3-30V setting.
  • state can be aquired by reading GPIO 12

Power and Ground

• +5V: Supplies a 5V output from the Raspberry Pi.
• GND: Connect to the system ground.

BPGND, BPNO, BPNC

• These terminals represent an open relay that you can configure as needed.
  • Example Use: Route COS to PTT Input for standalone repeater functionality.
  • drive by GPIO 8
• There is also an audio bypass function available (controlled via GPIO7 on the Raspberry Pi) in a false state audio is in passthrough.

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Feel free to reference this guide as you set up your breakout board.

Modify volume

Modify repeater_volume to your needs ...

vi /usr/sbin/repeater_volume

You can use arecord to fine tune the audio in and output levels

systemctl stop svxlink
/sbin/repeater_volume
arecord -V stereo -r 44100 -f S16_LE -c 2 /dev/null

New version !!! With Breackout board !!!

Main PCB

Installation Picture's

ON0AND

ON0HAL

ON0ORA

ON7FQ