SIM7600G-H 4G HAT (B) Setup Guide
What You'll Achieve
A reliable 4G LTE uplink through the SIM7600G-H HAT. The Aircast image recognises this modem and sets it up for you — it switches the modem into QMI mode and brings the connection up over NetworkManager. There are no AT commands and no manual networking to run.
Why the SIM7600G-H HAT?
- Auto-configured — Aircast detects the SIM7600 family and sets it up on first boot
- HAT form factor — mounts straight onto the Raspberry Pi
- Global coverage — the SIM7600G-H is a multi-band, worldwide LTE modem
- External antennas — better signal at altitude than a bare USB stick
LED Status Indicators:
- Blinking NET LED: registered on the network
- Solid / off NET LED: searching or not registered — check the SIM, antenna, and signal
Safety Notice
Power the Pi off before seating or removing the HAT. The Pi 4 runs hot under load — keep it cooled and ventilated, and never hot-plug the HAT while the Pi is powered on.
Before You Start
Make sure you have everything ready:
- SIM7600G-H 4G HAT (B) — the modem board with its LTE and GPS antennas
- Raspberry Pi 4 or Zero 2 W — flashed with the Aircast image
- Cooling solution — active cooling case or a heatsink with fan
- SIM card — with an active data plan and no PIN lock (or know the PIN)
- USB cable — to link the HAT's USB port to the Pi
1. Wire up the HAT
Power the Pi off first. Seating a HAT on a live Pi can damage both boards.
Mount the HAT on the Pi, insert the SIM card, and screw on the LTE and GPS antennas. Connect the HAT's USB port to a USB port on the Pi — that USB link carries the modem data, so it's required even though the HAT sits on the GPIO header.
2. Flash and boot — the modem configures itself
Flash the Aircast image, then power on the Pi. On first boot Aircast detects the SIM7600, switches it into QMI mode, and NetworkManager dials the connection with the default internet APN. Nothing to type.
The very first boot with a new modem takes about 40–50 seconds longer than usual: the mode switch is written to the modem's own memory, so it only happens once. Every boot after that connects straight away.
Haven't flashed yet? Grab the Aircast Flasher and follow the setup guide.
3. Verify the link on the dashboard
Open the device dashboard and go to the Network page. The Cellular modem card reports the modem in real time — carrier, signal strength, access technology (LTE), connection state, the IP address it was assigned, and live data counters. Once the card shows connected with an IP, your cellular uplink is live.
If the card says Collecting modem status… or No modem detected for the first minute of a fresh boot, that's the one-time QMI switch from step 2 finishing — give it a moment.
4. Set your carrier's APN (only if needed)
The image ships with the internet APN, which most carriers accept. If yours needs a different one, the modem registers on the network but never gets a data connection — the Cellular modem card shows it registered with no IP.
Fix it from the dashboard, no terminal needed: Network → Cellular modem → SIM & APN, enter your carrier's APN (and SIM PIN if the card is locked), and Save. Aircast re-dials the modem, so the link drops for a few seconds and comes back on the new APN.
Troubleshooting
Everything below is visible on the dashboard Network → Cellular modem card — start there.
No modem detected
- •Give a fresh boot up to a minute — the one-time QMI switch is still running
- •Reseat the HAT and the USB cable between the HAT and the Pi
- •Confirm the power supply can drive the Pi and modem under load
Registered but no data
- •Wrong APN — set your carrier's APN in SIM & APN (step 4)
- •SIM has no active data plan, or is out of balance
- •SIM is PIN-locked — enter the PIN in SIM & APN
Weak signal
- •Check both antennas are screwed on firmly
- •Keep the LTE antenna clear of the frame, ESCs, and power leads
- •Test in the open — the signal percentage is on the modem card
Poor performance
- •Watch for thermal throttling — keep the Pi cooled
- •Higher access tech (LTE over 3G) and higher signal both help — see the card
- •Try a different physical location or antenna placement
Support Resources
Flash your Pi in ~10 minutes
The Aircast Flasher downloads the image, sets Wi-Fi and hostname, and verifies the card — no terminal.
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