Use an iPhone as a Cellular Fallback Connection for your TinyPilot

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When your primary network goes down, getting back in can be a serious problem - especially if you don't have a dedicated cellular failover router. For smaller sites or remote racks, you can use an iPhone as a cellular fallback connection for your TinyPilot, with no additional hardware required.

If the primary network drops, this gives you a path back in to:

  • Start a KVM over IP session to access a critical server
  • Use the Serial Console to troubleshoot a failed switch, router, or firewall
  • Recover systems when standard remote access is no longer available

This is a practical fallback for maintaining access — not a replacement for a dedicated cellular router.

This setup assumes TinyPilot is connected to a Zero Trust overlay network such as Tailscale, ZeroTier, or NetBird. TinyPilot maintains an outbound, encrypted connection to the overlay network, so no inbound ports are exposed over the cellular link. The cellular connection simply becomes a secondary transport path.

Note: Cellular performance can vary widely by location and carrier. Before leaving an installation, adjust TinyPilot’s video quality to conserve bandwidth and optimize performance.

Requirements

  • A TinyPilot Voyager device with SSH enabled
  • A Zero Trust overlay network, like Tailscale
  • An iPhone with a tethering-enabled cellular data plan
  • A USB-A cable (data + charging) to connect the iPhone to TinyPilot

Step 1: Prepare the iPhone

On the Phone:

  • Go to Settings → Personal Hotspot
  • Enable "Allow Others to Join"

Step 2: Connect the iPhone to TinyPilot

  • Plug the iPhone into a USB-A port on your TinyPilot device
A picture showing a white usb cable plugged into a Voyager 3.
Use the Utility port on a Voyager 3.
A picture showing a white usb cable plugged into a Voyager 2.
Use any USB-A port on a Voyager 2.

Step 3: Run the iPhone Tether Setup script

SSH into your TinyPilot and run the following commands to download and set up the fallback connection (you can inspect the source here):

curl -sLO https://gist.githubusercontent.com/scott-tp/739af4f14afdf4b685d342ae1ae9cbfa/raw/iphone-tether-setup.sh && \
  sudo ./iphone-tether-setup.sh

Note: You must tap "Trust" on the iPhone when prompted.

The script installs packages to communicate and pair with the iPhone, and installs a watchdog service. The watchdog (persistent across reboots) keeps cellular in standby, automatically fails over when the primary network drops, and restores the primary connection when it becomes available.

Step 4: Verify

  • Run  sudo systemctl status mobile-tether-watchdog
  • Look for Active: active (running)

The watchdog now monitors the primary network and automatically fails over to cellular when needed, then returns to the primary connection once it recovers.

What to expect

Once configured, TinyPilot will continue using the primary network under normal conditions. If connectivity is lost, the watchdog service will automatically route traffic over the iPhone’s cellular connection.

When the primary network returns, TinyPilot will switch back automatically.

Failover is not instantaneous — expect a brief interruption while connections reset and re-establish over the cellular link.

When to use this

This setup works well for:

  • Remote racks without dedicated cellular infrastructure
  • Small office or edge deployments
  • Temporary installations or staging environments
  • MSP-managed sites that need a quick fallback option

It is not a replacement for a dedicated cellular router, but it provides a fast, low-effort way to maintain access when the network fails.

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