This information only applies to using trmnl.com as your device's server (where you organize plugins and playlists). If you are using a BYOS (Bring Your Own Server) solution, this is not applicable unless proxying (server-specific feature).
These are the domains that your TRMNL device uses to download its next screen:
https://trmnl.app - Receiving information about the next screen
time.google.com, with pool.ntp.org as a fallback (time.cloudflare.com on a TRMNL X connected to 5 GHz WiFi) - Accurate time keeping (NTP, UDP port 123)
https://trmnl.s3.us-east-2.amazonaws.com - Downloading the screen itself (PNG file)
https://trmnl-public.s3.us-east-2.amazonaws.com - Static screens, such as the sleep screen, on a BYOD device with a custom screen size
https://trmnl-fw.s3.us-east-2.amazonaws.com - Downloading firmware updates
https://trmnl.com (static screens, such as the sleep screen)
*.digitaloceanspaces.com
If a TRMNL device can connect and retrieve screens via one network or hotspot but not another, and you are sure the WiFi connection is working properly, this can be a possible cause of problems in restrictive environments.
If you are on a corporate network, it may require whitelisting to access particular domains, or verifying that traffic to these domains is not blacklisted.
Pi-Hole Query Log
If you use Pi-Hole as a DNS server in your home network, you can check your query log to ensure all requests are being allowed through:
If any of these requests are blocked, your TRMNL device will not be able to retrieve the next screen to display.
Have a TRMNL X? Our troubleshooter walks you through the most common problems in a couple of minutes.
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