Disaster channel ptp-bousai

A channel that carries Japanese disaster information — earthquakes, weather warnings, typhoons — verbatim, as it arrives. Set it up and you receive without asking. It is opt-in and does not affect any of your existing channels.

To listen you do not need MQTT. Enter the name and PSK, and be within range of a gateway.

What to set (only two things)

Add one channel in the app and fill in these two fields.

Field	Value
Name	ptp-bousai
PSK	Bg==

The PSK is where people get stuck

The app asks you to pick a key size. Bg== is a 1-byte key. If the selector is left on 256-bit it will not accept it. Choose 1 byte first, then enter Bg==.

• The channel index does not matter. Channels are identified by name and PSK, so any slot works (max 8).
• Do not change your primary channel. This goes in a secondary slot.
• Leave Uplink OFF (receive only).

If you run a gateway

Turn Downlink ON for this channel. A gateway cannot re-radiate a channel it cannot decrypt, so without it you get the "I configured it but nothing arrives" state. Also issue --ch-set one item at a time (batching them is a known failure).

meshtastic --host <node> --ch-index 2 --ch-set name ptp-bousai
meshtastic --host <node> --ch-index 2 --ch-set psk base64:Bg==
meshtastic --host <node> --ch-index 2 --ch-set downlink_enabled true

Note the CLI displays a 1-byte key as psk=simple5 (the same thing as Bg== = 0x06).

What arrives

• Nothing is filtered out. Even intensity 1 comes through. This is everything, not "just the important ones".
• One event arrives as several messages. It is relayed verbatim, so a single earthquake typically produces 6 messages (headline → detail → map URL → max intensity → felt areas → tsunami status) about 12 seconds apart. This is not a malfunction.
• Normal-day volume is roughly 3–4 messages per hour (measured; about half weather warnings, the rest earthquakes and typhoons).
• The text stays in English (ASCII) — the on-device fonts and the 237-byte packet limit make that the practical choice.

If you prefer to pull rather than receive, use kbot, which summarises one event into one message. The two paths are independent; using only one is fine.

Source and disclaimer

Republished with permission from JPEQ (by YNGMT). It appears in node lists as JPEQ mirror by YNGMT.

Accuracy and timeliness are not guaranteed. For evacuation decisions always use official JMA and municipal sources.

Reading JMA romanised place names

Place names are JMA's own romanisations. These are regional subdivisions that are not obvious even to Japanese readers. Taken from names actually observed on the channel.

As shown	Meaning
Kaetsu NIIGATA	Kaetsu district, Niigata (northern Niigata)
Chuetsu NIIGATA	Chuetsu district, Niigata (central)
Joetsu NIIGATA	Joetsu district, Niigata (southern)
Sado NIIGATA	Sado Island, Niigata
Okitama YAMAGATA	Okitama district, Yamagata
Aizu FUKUSHIMA	Aizu district, Fukushima
Kaga ISHIKAWA	Kaga district, Ishikawa (southern)
Noto ISHIKAWA	Noto peninsula, Ishikawa (northern)
Satsuma, KAGOSHIMA	Satsuma region, Kagoshima
Near Tokara Islands, KAGOSHIMA	Waters near the Tokara Islands
Hyuganada Sea, KYUSHU Region	Hyuganada Sea, off eastern Kyushu
Off Tomakomai, HOKKAIDO	Off Tomakomai, Hokkaido

Names with a compass direction are simply prefectural subdivisions: Northern IBARAKI, Southern NAGANO, Eastern TOYAMA and so on.

Symbols in the messages

Symbol	Meaning
M2.7	Magnitude
I:1	Max JMA seismic intensity (shindo)
D:20km	Hypocentre depth
[FINAL]	Confirmed information
PRELIMINARY	Early warning — before confirmation. The numbers will change
[EEW #N]	Earthquake early warning, Nth bulletin
<D/G>	A warning was cancelled or downgraded
L:3->2	Alert level went from 3 down to 2