---

==The MeshAdv Mini has just been released, the project and this README is currently a work in progress==

The MeshAdv Mini is a Lora/GPS Raspberry Pi hat designed to be used with the Linux-native version of Meshtastic known as meshtasticd. It is similar to its big brother, the MeshAdv Pi Hat, but half the size and fits perfectly on the Pi Zero lineup. The board includes a +22dbm LoRa module, integrated GPS module, HAT+ EEPROM, Temperature Sensor, 5V PWM Fan header, and breakout for I2C bus including two Qwiic connectors. This makes for a good "base station" or "Router" node that can be mounted high on a pole and powered over POE (using separate POE adapter or Hat). No more need to retrieve the node everytime you want to update firmware, it can all be done remotely. It also makes it easy and reliable to connect to MQTT.

---

Fully Assembled units available here: https://frequencylabs.etsy.com

== NOTICE!! always have an antenna connected to the LoRa module when powered on, failure to do so can damage the module. ==

Info

Pin#	GPIO	Pin Name	Description			Pin#	GPIO	Pin Name	Description
1		3.3V				2		5V
3	2	SDA	(I2C1)			4		5V
5	3	SCL	(I2C1)			6		GND
7	4	GPSEN	(GPS) GPS Enable			8	14	UART TX	(GPS)RX
9		GND				10	15	UART RX	(GPS)TX
11	17	PPS	(GPS) 1 Sec Pulse			12	18	FANPWM	Fan Speed PWM
13	27	Unused				14		GND
15	22	Unused				16	23	Unused
17		3.3V				18	24	RST	(LoRa) Reset
19	10	MOSI	(LoRa)			20		GND
21	9	MISO	(LoRa)			22	25	Unused
23	11	CLK	(LoRa)			24	8	CS	(LoRa) Chip Select
25		GND				26	7
27	0	ID-SDA	(I2C0) For HAT+ EEPROM			28	1	ID-SCL	(I2C0) For HAT+ EEPROM
29	5	Unused				30		GND
31	6	Unused				32	12	RXEN	(LoRa) Recieve Enable
33	13	Unused				34		GND
35	19	Unused				36	16	IRQ	(LoRa)
37	26	Unused				38	20	BUSY	(LoRa)
39		GND				40	21	Unused

Compatibility

Raspberry Pi Model	Working?
Raspberry Pi 1 Model A	Never*
Raspberry Pi 1 Model A+	???
Raspberry Pi 1 Model B	Never*
Raspberry Pi 1 Model B+	???
Raspberry Pi 2 Model B	Yes
Raspberry Pi 3 Model B	Yes
Raspberry Pi 3 Model B+	Yes
Raspberry Pi 3 Model A+	Yes
Raspberry Pi 4 Model B	Yes
Raspberry Pi 400	Yes
Raspberry Pi 5	Yes
Raspberry Pi 500	Yes
Raspberry Pi Zero	Yes
Raspberry Pi Zero W	Yes
Raspberry Pi Zero 2 W	Yes
Raspberry Pi Pico	Never*
Raspberry Pi Pico W	Never*

*Raspberry Pi 1 Model A, 1 Model B, and Pico do not implement the 40-pin layout used in the MeshAdv Pi Hat.

Installing Meshtasticd

You can try my new Configuration Tool, It can install and configure everything you need to get up and running, otherwise continue below with the official instructions.

Watch this video first: How to install Meshtastic on Raspberry Pi This video covers the old method, still a good video but out of date.

Official installation instructions: [https://meshtastic.org/docs/hardware/devices/linux-native-hardware/]

Configuration

==This hat features HAT+ compatibility with an onboard EEPROM for quick setup. This feature is currently experimental==

These instructions assume you are using a raspberry pi with Raspberry Pi OS.

New Method:

• As methods keep changing, please CLICK HERE for the most up to date configuration process
• There was an error in the initial config.d file. It has been fixed but may take a while to migrate to Beta. Please copy the file from here in the meantime: Download

---

Old Method:

• The old method is below and still works if you prefer it

sudo nano /etc/meshtasticd/config.yaml

add or uncomment the following lines as needed.

Lora:
  Module: sx1262  # Ebyte E22-900M22S choose only one module at a time
# Module: sx1268  # Ebyte E22 400M22S
  CS: 8  
  IRQ: 16
  Busy: 20
  Reset: 24
  RXen: 12
  DIO2_AS_RF_SWITCH: true
  DIO3_TCXO_VOLTAGE: true

GPS:
  SerialPath: /dev/ttyS0

I2C:
  I2CDevice: /dev/i2c-1

Logging:
  LogLevel: info # debug, info, warn, error

Webserver:
  Port: 443 # Port for Webserver & Webservices
  RootPath: /usr/share/meshtasticd/web # Root Dir of WebServer

General:
  MaxNodes: 200

LoRa Setup:

• You must now set the LoRa Region to be able to start using Meshtastic. CLICK HERE for info on how to set region settings. Please note: Linux-Native is currently unable to connect over bluetooth or to the Apple app. All other methods are working.

---

GPS

• The ATGM336H-5NR32 can receive the GPS and BeiDou constellations. It is fully integrated into the MeshAdv Mini with the ability to put the GPS to sleep for low power consumption and also utilize the PPS output for very precise time keeping, useful for running an NTP server alongside Meshtastic.

• Backup Battery: The recommended GPS backup battery is the official Raspberry Pi 5 RTC battery. This is a rechargable battery so make sure you do not use a standard non-rechargable battery.

• Start by following the official instructions to get the GPS working with meshtasticd CLICK HERE

• GPS can be turned on or off manually using GPIO4. If you do not plan to use this feature and you want to enable it full-time, you need to change the startup setting for the GPIO pin.

  Edit the config.txt file:

  sudo nano /boot/firmware/config.txt

  Add the following line to the bottom

  gpio=4=op,dh #Enables GPS

• Verify that your GPS serial port is defined in /etc/meshtasticd/config.yaml. This will be either /dev/ttyAMA0 for pi 5, or /dev/ttyS0 for earlier pis.

  Edit the config.yaml file:

  sudo nano /etc/meshtasticd/config.yaml

  Make sure the GPS line looks something like this:

  GPS:
    SerialPath: /dev/ttyS0

  Restart meshtasticd:

  sudo systemctl stop meshtasticd && sudo systemctl start meshtasticd

• Now you must enable the GPS in the Position module. This will be labeled "GPS Mode", change it to Enabled and save. (You can do this using the web interface, remember to enable the web interface in the /etc/meshtasticd/config.yaml and restart meshtasticd. Remember to add the port number to the end of your IP address in the web browser).

• PPS Time Correction:

  ▶️ Click to Show Instructions

  1. Enable PPS Support in Raspberry Pi OS

  Edit the config.txt file:

  sudo nano /boot/firmware/config.txt

  Add the following line at the bottom:

  dtoverlay=pps-gpio,gpiopin=17

  Save and exit (CTRL+X, then Y, then ENTER).

  Reboot the Raspberry Pi:

  sudo reboot

  ---

  2. Verify PPS Signal

  After reboot, check if the PPS device is detected:

  ls /dev/pps*

  Expected output:

  /dev/pps0

  Install pps-tools:

  sudo apt update
  sudo apt install pps-tools

  Check if PPS is generating pulses:

  sudo ppstest /dev/pps0

  Expected output (timestamps every second):

  trying PPS source "/dev/pps0"
  found PPS source "/dev/pps0"
  ok, found 1 source(s), now start fetching data...
  source 0 - assert 1672531199.999999999, sequence: 12345 - clear  0.000000000, sequence: 0
  

  ---

  3. Sync System Time with PPS

  Install chrony:

  sudo apt update
  sudo apt install chrony

  Edit the Chrony config:

  sudo nano /etc/chrony/chrony.conf

  Add the following at the end:

  # Use PPS signal for accurate timing
  refclock PPS /dev/pps0 lock GPS prefer

  Restart Chrony:

  sudo systemctl restart chronyd

  Check PPS synchronization:

  chronyc sources -v

  Expected output should show PPS as a preferred time source.

  ---

  4. (Optional) Sync GPS Time via NMEA

  If you want both GPS time and PPS, modify chrony.conf to include:

  refclock SHM 0 delay 0.5 refid GPS
  refclock PPS /dev/pps0 lock GPS prefer

---

Temp Sensor TMP102

• The MeshAdv Mini has an onboard Texas Instruments TMP102 temp sensor soldered in the center of the board near the EEPROM to get a general idea of board/enclosure temperature with 0.5°C accuracy. This sensor uses I2C address 48.

▶️ Click to Show Instructions

---

Step 1: Enable I2C on the Raspberry Pi

1. Open the Raspberry Pi configuration tool:

   sudo raspi-config

2. Go to "Interface Options" > "I2C", enable it, and exit.
3. Reboot the Pi to apply changes:

   sudo reboot

---

Step 2: Install Required Packages

Update your package list and install I2C tools and Python SMBus:

sudo apt update
sudo apt install i2c-tools python3-smbus -y

---

Step 3: Verify the TMP102 Connection

Find the I2C address of the TMP102 sensor:

sudo i2cdetect -y 1

• If connected correctly, you should see 0x48 (default address).

---

Step 4: Create the Python Script

1. Open a new script file:

   sudo nano tmp102.py

2. Paste the following Python code:

   #!/usr/bin/env python3
   import smbus
   import time
   
   # I2C setup
   bus = smbus.SMBus(1)  # Use I2C bus 1
   TMP102_ADDR = 0x48  # Default I2C address for TMP102
   
   def read_temp():
       """Reads temperature from TMP102 and converts it to Celsius"""
       raw = bus.read_word_data(TMP102_ADDR, 0)
       
       # Swap byte order (TMP102 stores in little-endian)
       raw = ((raw << 8) & 0xFF00) + (raw >> 8)
       
       # Convert to temperature (TMP102 uses 12-bit resolution)
       temp_c = (raw >> 4) * 0.0625
       return temp_c
   
   if __name__ == "__main__":
       while True:
           print(f"Temperature: {read_temp():.2f}°C")
           time.sleep(1)

3. Save and exit (CTRL+X, then Y, then Enter).

---

Step 5: Make the Script Executable

Run this command to make the script executable:

sudo chmod +x tmp102.py

---

Step 6: Run the Script

Now, you can run the script in two ways:

1️⃣ Using Python:

python3 tmp102.py

2️⃣ Directly from CLI:

./tmp102.py

---

---

PWM Fan

• The onboard PWM fan connector can support 2 wire 5V fans (Always on), and 4-pin PWM (Tach not implemented). I recommend the Noctua NF-A4x10 5V PWM 40mm 0r Noctua NF-A8 5V PWM 80mm

• Setup:

  ▶️ Click to Show Instructions

  ---

  Option 1: (Easiest - Works with Pi 4 and 5 only) Use the built-in fan control tool to turn fan on and off

  1. Open the raspi-config tool by running the following:

     sudo raspi-config

  2. Navigate to the "Performance Options" section.

  3. Select "Fan" and enable the fan control.

  4. Set the GPIO pin to 18 and temperature threshold for the fan to start. By default, the fan starts at 60°C, but you can modify this by editing the /boot/firmware/config.txt file manually.

     sudo nano /boot/firmware/config.txt

     add the following:

     dtoverlay=gpio-fan,gpiopin=18,temp=60000

  5. Exit and reboot

     ---

  Option 2 (works for most Pi models)

  1. Install the Rpi.GPIO Python library

     sudo apt update && sudo apt install python3-rpi.gpio

  2. Create a new file called fan_control.py

     sudo nano fan_control.py

  3. Copy the following and save the file:

     #!/usr/bin/env python3
     import RPi.GPIO as GPIO
     import time
     
     # Configuration
     FAN_PIN = 18
     TEMP_THRESHOLD_LOW = 45.0  # Temperature (°C) at which fan runs at minimum speed
     TEMP_THRESHOLD_HIGH = 60.0  # Temperature (°C) at which fan runs at max speed
     
     # Initialize GPIO
     GPIO.setmode(GPIO.BCM)
     GPIO.setup(FAN_PIN, GPIO.OUT)
     pwm = GPIO.PWM(FAN_PIN, 25000)  # 25 kHz PWM frequency
     pwm.start(0)  # Start with fan off
     
     def get_cpu_temp():
         """Reads the CPU temperature."""
         with open("/sys/class/thermal/thermal_zone0/temp", "r") as f:
             return int(f.read()) / 1000  # Convert from millidegrees to degrees
     
     def set_fan_speed(temp):
         """Adjusts fan speed based on temperature."""
         if temp < TEMP_THRESHOLD_LOW:
             duty_cycle = 0  # Fan off
         elif temp > TEMP_THRESHOLD_HIGH:
             duty_cycle = 100  # Full speed
         else:
             # Scale between min and max speed
             duty_cycle = (temp - TEMP_THRESHOLD_LOW) / (TEMP_THRESHOLD_HIGH - TEMP_THRESHOLD_LOW) * 100
         pwm.ChangeDutyCycle(duty_cycle)
     
     try:
         while True:
             temp = get_cpu_temp()
             set_fan_speed(temp)
             print(f"CPU Temp: {temp:.1f}°C | Fan Speed: {int(pwm.ChangeDutyCycle)}%")
             time.sleep(5)  # Check every 5 seconds
     except KeyboardInterrupt:
         print("Fan control stopped")
         pwm.stop()
         GPIO.cleanup()

  4. Make the file executable

     chmod +x fan_control.py

  5. Optional: Run script at boot

     crontab -e

     Add this line at the end:

     @reboot /usr/bin/python3 /path/to/fan_control.py &

     Hint: use pwd command to find your current directory. Change "/path/to" the location of your script.

  Pin	Name	Color
  1	Ground	Black
  2	5V	Yellow
  3	NC	Green
  4	PWM	Blue