Flashing the Room Server

Load room server firmware, set the UK radio settings, and confirm first boot

This will feel familiar - it is the same flasher and the same process you used in part one, with a different firmware variant selected.

Before you start

• Fit the antenna. Same rule as always, and it still matters
• Use Chrome or Edge - WebUSB and Web Serial do not exist in Firefox or Safari
• Have your USB-C data cable ready, not a charge-only one
• Label this board ROOM before you start. In an hour you will have three near-identical green boards on the desk

Flashing

1. Fit the antenna, then plug the board into your computer
2. Open flasher.meshcore.io
3. Select your board: Heltec V3
4. Select the firmware variant: Room Server
5. Select the region preset: EU/UK (Narrow) - the same one your repeater and client are on
6. Click Flash and choose the serial port
7. Wait for the reboot

If the port list is empty, it is almost certainly the cable. That was true in part one and it is still true now.

Confirm the radio settings

Connect the console - either the console feature on the flasher page, config.meshcore.io, or a serial terminal at 115200 baud.

ver
get role
get radio

You should see a firmware version, a role of room server, and your radio parameters. Check them against the rest of your mesh:

If anything is off:

set radio 869.618,62.5,8,8
reboot

Why this matters: a room server on the wrong settings is not a broken room server, it is an invisible one. It will sit there working perfectly, heard by nobody. This is the number one cause of “my new node does not show up”.

Set the clock

clock sync

Or from a plain terminal with no sync button:

time <unix-epoch-seconds>

Why this matters more here than on a repeater: a room server uses timestamps for sync points. Each client records where it got to, and the server works out what to send based on that. A room server with a badly wrong clock will deliver the wrong set of posts, or none at all, in a way that is genuinely confusing to debug.

The server also rejects logins whose timestamp is not newer than the last one it recorded from that client - a replay protection measure. A clock that jumps backwards can lock a client out until it catches up.

Set the clock. It takes five seconds and saves an evening.

Check the transmit power

get tx

A room server is fixed and mains powered, so there is no reason to be shy:

set tx 20

The valid range is 1 to 22 dBm, and the Heltec V3 tops out around 21 (Heltec quote 21 ±1 dBm).

What the screen shows

The OLED on a room server will show its name, uptime, and packet counters, much like the repeater. It will not show posts - the room’s contents live in memory and are served over the radio, not displayed.

If the screen is blank but the board is warm, the flash probably failed partway. Flash it again; nothing is harmed by reflashing.

Try it Yourself

1. Run ver, board and get role and note what each returns. Compare get role against your repeater.
2. Run get radio on the room server and on the repeater. Do the four numbers match exactly?
3. Challenge: reflash this board as a repeater, confirm get role changes, then flash it back to room server. Reflashing is cheap and being comfortable with it removes a lot of fear later.

Common Issues

Problem: There is no Room Server variant listed for my board.

Solution: Check you selected the right board, and check the firmware version. If your hardware genuinely has no room server build, you will need to build it yourself from the MeshCore repository.

Why: Firmware variants are compiled per board. Not every supported board gets every role in the prebuilt list.

Problem: The console connects but every command returns nothing.

Solution: Check the baud rate is 115200, and press enter on a blank line first.

Why: Some terminals need a newline to wake the prompt, and any other baud rate turns the reply into noise.

Problem: set freq is rejected over the air.

Solution: Set frequency from the USB serial console instead.

Why: Frequency is serial-only for setting on some builds - deliberately, because changing it remotely instantly disconnects you from the node you are configuring.

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