Below is a work-in-progress collection of potential issues + fixes to ensure your TRMNL device remains connected.

If you've just unboxed your TRMNL, see the following tips.

On your phone or computer, click "forget network" (or similar feature), then restart your device and re-connect to TRMNL WiFi.

Like many IoT devices, TRMNL requires a 2.4ghz network. If you only have 5ghz enabled on your router, you can usually enable dual band with no changes required for your existing devices.

It's ideal to have a separate, dedicated 2.4ghz network versus a "dual band" network, because routers with dual-band enabled will often instruct devices to use the 5ghz band, which is incompatible with most IoT devices.

If you're setting up TRMNL in a building with "hotel style" WiFi, whereby you must input credentials inside a captive portal popup following network connection, TRMNL must be accompanied by a middleware device.

One user reported buying this $35 Opal Router (Amazon) and using it to quickly bypass their network's captive portal configuration. Then you can connect TRMNL to this router's access point with no issues.

If you're inputting your home or office network's WiFi credentials into the TRMNL WiFi portal, but the device is not connecting or showing an error screen, check out the security settings on your router. While TRMNL should work with WPA, WPA2, and WPA3, some users have reported that only WPA3 connections were successful for their device.

Another thing to check is whether https://trmnl.app loads on your local network. Just use your phone (on WiFi) or computer and visit the URL. If it doesn't load, your router or ISP is blocking the endpoint that our Firmware pings for screen content. Either read this guide and modify this line of code to https://usetrmnl.com to resolve yourself, or send us a live chat / support ticket and we'll walk you through it in real time.

If you've already set up your TRMNL but are experiencing new issues, see the following tips. We will update this as often as we detect a new pattern.

For live help, open the chat widget in the bottom right corner and ping us in real time. Be ready to share your router brand / model or other home networking settings to help us help you.

Our firmware packages are only around 1.4mb, however it may take a few minutes for the package to be installed on your device following a download. We do not recommend clicking the boot button to 'skip' this update, or turning your device off/on.

If you prefer to disable firmware updates, simply visit Devices > Edit > scroll down and uncheck the "OTA Updates" feture. Note that this requires the Developer edition perk, but if you don't have that enabled then you can send us a live chat and we'll do it on your behalf.

If your TRMNL sometimes displays content as expected, but at other times shows an error screen, it's possible the buffer needs to be reset.

Simply turn off your device for 5-7 seconds (this length of time is necessary), then turn it back on.

Suggestion: If you have ad blockers installed at the router-level, try whitelisting the domain "https://trmnl.app". This is the endpoint where the device firmware fetches new content.

Suggestion: Set your Device's refresh rate (visit Devices > Edit > scroll down) to 5 minutes, then click the button on the back of your device 1x. This should sync your new refresh rate. Then, wait 5 minutes for the device to perform a full refresh cycle (sleep, wake, request content).

Suggestion: To help us confirm if this is a local network issue (vs device / firmware related), try connecting your TRMNL to your phone's hotspot. If you're using an iPhone > Personal HotSpot, make sure to toggle on "Maximize Compatibility" (beneath your editable WiFi Password field).

Our friends at HostiFi wrote this article with tips to ensure iOT devices like TRMNL play nicely with your network.

Without a proper setup, your router's default feature "Band Steering" will direct TRMNL devices to leverage the 5ghz band which will not work, even if you connected to 2.4ghz during setup.

Below are some router settings from another user that fixed their connectivity issues. They have a 2.4ghz-only SSID with multiple IoT devices:
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If some of the above parameters don't work, try setting just your router's "Minimum Data Rate Control" setting to a minimum of 12mbps on the 2.4ghz network.

In general, device connectivity issues are a mix of local networking / router quirks and some ongoing compatibility improvements being made to our open source firmware:

https://github.com/usetrmnl/firmware

So if your device is having issues, rest assured that we can probably fix it with a little bit of back and forth debugging, and your hardware is in good condition otherwise.

(As of this writing in November 2024 we've shipped 1,500 devices. Only 1x had a broken WiFi receiver on the board, which we immediately replaced at no cost to the customer.)