RTL-SDR/LoRa/GPS/RTC/USBHUB Setup Guide

Recommand Operating System.

It is recommended to use Rex's ported Bookworm image, which has SDR++ pre-installed in its software repository and already includes the dependencies required for Meshtasticd (LoRa) installation. The image can be downloaded from:https://forum.clockworkpi.com/t/bookworm-6-6-y-for-the-uconsole-and-devterm/13235

RTC Setup

Add the following code to the /boot/firmware/config.txt file to enable RTC functionality.
```
# Clock
dtparam=i2c_arm=on
dtoverlay=i2c-rtc,pcf85063a
```
Restart uConsole and use the sudo hwclock -r command to check if it's working. If successful, you should see the output like this:
```
pi@clockworkpi:~ $ sudo hwclock -r
2025-01-04 17:21:37.491776+08:00
```
If you don't see any output, please check if the battery is installed or if it's inserted backwards.

RTL-SDR Guide

Using Rex's ported Bookworm image, you can install SDR++ directly with sudo apt sdrpp. For other images, please refer to the SDR++ installation guide.
Connect the antenna to the IPEX antenna connector labeled "SDR" on the expansion board.
After installation, enter sdrpp in the terminal to start SDR++.

In the dropdown box indicated by arrow 1, select RTL-SDR.

In the dropdown box indicated by arrow 2, choose the RTL-SDR device with serial number 00000002.

Adjust the reception frequency at the location indicated by arrow 3. It is recommended to tune to local FM radio stations.

Select the modulation type for the frequency at the location indicated by arrow 4. For FM radio stations, choose WFM.

Click the play button indicated by arrow 5. You should see a waterfall display like the one below and hear the radio broadcast sound from the speaker.
In addition to SDR++, the Raspberry Pi also supports other SDR software like GQRX. You can explore these options on your own.

GPS Setting

Add the following code to the /boot/firmware/config.txt file to enable the serial port functionality:

For CM4:
```
enable_uart=1
```
For CM5:
```
dtparam=uart0
```
Connect the antenna to the IPEX antenna connector labeled "GPS" on the expansion board. The expansion board supports both active and passive GPS antennas.

Restart uConsole, and use the command sudo minicom -D /dev/ttyS0 -b 9600 to view the GPS module output. If you are using the CM5, the command would be sudo minicom -D /dev/ttyAMA0 -b 9600. Under normal conditions, you should see output like the following:

Welcome to minicom 2.8

OPTIONS: I18n 
Port /dev/ttyS0, 18:01:36

Press CTRL-A Z for help on special keys

$GNGGA,100139.000,2307.73354,N,11322.65974,E,1,09,2.3,43.1,M,-6.8,M,,*6F
$GNRMC,100139.000,A,2307.73354,N,11322.65974,E,0.00,0.00,040125,,,A,V*08
$GNGGA,100140.000,2307.73342,N,11322.65968,E,1,09,2.3,43.0,M,-6.8,M,,*6A
$GNRMC,100140.000,A,2307.73342,N,11322.65968,E,0.00,0.00,040125,,,A,V*0C
$GNGGA,100141.000,2307.73330,N,11322.65962,E,1,09,2.3,43.0,M,-6.8,M,,*64
$GNRMC,100141.000,A,2307.73330,N,11322.65962,E,0.00,0.00,040125,,,A,V*02
$GNGGA,100142.000,2307.73319,N,11322.65956,E,1,09,2.3,43.0,M,-6.8,M,,*6B
$GNRMC,100142.000,A,2307.73319,N,11322.65956,E,0.00,0.00,040125,,,A,V*0D

Each line following the N (latitude) and E (longitude) will show the current GPS coordinates. If the output is empty, please try again in an open outdoor area for better satellite reception.

Meshtastic（LoRa）Setting

Add the following code to the /boot/firmware/config.txt file to enable SPI1 functionality:
```
dtparam=spi=on
dtoverlay=spi1-1cs
```
Connect the 433/915MHz antenna to the IPEX antenna connector labeled "LoRa" on the expansion board.
If you're using the Rex Bookworm image, you need to stop the devterm-printer service first, as the Devterm printer also uses SPI1 GPIO, which may cause conflicts. The command to stop the service is:
```
 sudo systemctl stop devterm-printer.service
 sudo systemctl disable devterm-printer.service
```

Use the following command to install the dependencies required for Meshtasticd:

sudo apt install libgpiod-dev libyaml-cpp-dev libbluetooth-dev libusb-1.0-0-dev libi2c-dev openssl libssl-dev libulfius-dev liborcania-dev

To download and install Meshtasticd, you can use the following command (You can obtain the latest version from the official MeshTastic GitHub page):

wget <https://github.com/meshtastic/firmware/releases/download/v2.5.18.89ebafc/meshtasticd_2.5.18.89ebafc_arm64.deb>
sudo apt install ./meshtasticd_2.5.18.89ebafc_arm64.deb

To modify the LoRa module configuration in the /etc/meshtasticd/config.yaml file, update the configuration section to the following:
```
Lora:

  Module: sx1262  # HackerGadgets RTL-SDR/LoRa extension board
  DIO2_AS_RF_SWITCH: true
  IRQ: 26
  Busy: 24
  Reset: 25
  spidev: spidev1.0
```
To enable the GPS functionality in Meshtasticd, first ensure you have completed the necessary GPS setup as described earlier. Then, in the configuration file /etc/meshtasticd/config.yaml, uncomment the GPS-related configuration section and modify it as follows:
```
GPS:
  # change the path to /dev/ttyAMA0 if you are using CM5
  SerialPath: /dev/ttyS0 
```
To create the Meshtasticd service using this sudo nano /etc/systemd/system/meshtasticd.service，and fill in the follows content：
```
[Unit]
Description=Meshtastic Daemon
After=network.target

[Service]
ExecStart=/usr/sbin/meshtasticd
Restart=always
User=root
Group=root
Type=simple

[Install]
WantedBy=multi-user.target
```
Reload systemd services to apply any changes:
```
sudo systemctl daemon-reload
```
Enable Meshtasticd to start on boot:
```
sudo systemctl enable meshtasticd
```
Start the Meshtasticd service:
```
sudo systemctl start meshtasticd
```
Check the status of the Meshtasticd service: This will show whether the service is running correctly or if there are any issues.
```
sudo systemctl status meshtasticd
```
If the service is not running as expected, view the log output for detailed error messages:
```
sudo journalctl -u meshtasticd -b
```
This command will show the logs related to meshtasticd since the last boot, helping you debug and fix any issues based on the error messages.
Meshtasticd has web server support starting with release 2.3.0, uncomment the web server related configuration section in the configuration file /etc/meshtasticd/config.yaml, and modify it as follows:
```
Webserver:
  Port: 443 # Port for Webserver & Webservices
  RootPath: /usr/share/meshtasticd/web # Root Dir of WebServer
```
When you open the browser on uConsole and enter https://localhost, if you receive an SSL error, you can click on "Proceed to localhost (unsafe)" or "Continue to this website" depending on the browser.

Once you bypass the SSL warning, you should be directed to the following interface (the exact details may vary depending on your setup, but it will generally look something like this):
To establish a new connection with Meshtasticd via the web interface, follow these steps:
1. Click on "New Connection".
2. In the IP Address field, enter localhost instead of using the default meshstatic.local. This is because, when the system is not connected to a network, the local hostname (meshstatic.local) may not be resolvable.
3. After entering localhost, click on "Connect".
  
  This should establish a connection to the Meshtasticd service running on your local device. If everything is set up correctly, you should now be able to manage and monitor your Meshtastic device via the web interface.
For first-time use, go to the LoRa tab under the Config menu in the left Navigation bar to set the LoRa region. Meshtastic adjusts the LoRa frequency band based on the region setting, and different regions cannot communicate with each other.
Then, you can click on the Messages menu in the Navigation bar to send and receive messages on the public channel or between individual nodes.

If you need to use other LoRa applications or perform custom programming, please refer to the SX1262 module information. The only thing to note is the pin connections for the SX1262 module, which are as follows:

SPI：SPI1 #Use SPI1 as the communication port with the chip select signal set to SPI1-CE0 (GPIO 18),
DIO2_AS_RF_SWITCH: true #Controlling the antenna transmit/receive switch with SX1262's DIO2
IRQ: 26 #GPIO 26
Busy: 24 #GPIO 24
Reset: 25 #GPIO 25