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GenSlave

The GenSlave page shows the live status of the remote relay controller — the Pi Zero 2W that physically opens and closes the generator's start contact. Use this page to confirm the slave is healthy, view its network configuration, change the API secret used between GenMaster and GenSlave, configure failsafe notifications, and schedule maintenance reboots.

GenSlave page overview

Header summary

The top of the page shows whether GenSlave is currently reachable, plus four action buttons:

Field / Button Meaning
GenSlave: ONLINE / OFFLINE Live status badge. Green ONLINE means GenMaster has received recent heartbeats.
Hostname / Platform (e.g. genslave • linux) Identifies the slave device.
Refresh Forces an immediate re-poll of the slave.
Test Sends a ping to the slave's API to verify connectivity.
Reboot Reboots the GenSlave host. Only allowed when the relay is OFF.
Shutdown Powers off the GenSlave host. Only allowed when the relay is OFF. Use with care — you'll need physical access to power it back on.

Reboot/Shutdown affect a remote device

Both buttons act on the GenSlave Pi, not on GenMaster. After a Reboot the slave will return on its own; after a Shutdown someone must physically restore power.

At-a-glance health (CPU, Memory, Disk, Temp)

A row of four cards immediately below the header shows the slave's current resource usage. Numbers update on the refresh cadence (typically every 60 seconds).

Metric What it tells you
CPU Percentage of CPU in use. Spikes during reboots and software updates. Sustained high values suggest a runaway process.
Memory RAM in use vs. total. The Pi Zero 2W has only 416MB usable, so anything above ~80% should be investigated.
Disk Free space on the SD card / SSD.
Temp Core temperature. Above ~167°F (75°C) the Pi will throttle. Normal, Warm, Hot badges flag the current zone.

System Information

A collapsible panel showing the slave's identity and hostname, IP address (LAN), platform string, uptime, and software version. Click the row to expand.

GenSlave — System Information expanded

When expanded you'll see:

  • Hostname — the slave's network name (default genslave).
  • Platform — linux (or linux-mock in dev mode).
  • IP Address — LAN IP.
  • Uptime — time since the slave's last boot.
  • Version — slave software version.

The same panel also surfaces Relay & Health Status and Failsafe Monitoring sub-sections (documented in their own headings below).

Sensitive data

The IP address shown in this panel is your slave's local LAN address. If you publish screenshots externally, mask the third and fourth octets.

Relay & Health Status

Shows what the slave's automation relay is currently doing.

Field Meaning
Relay State OFF or ON. This is the actual GPIO state on the Pimoroni Automation Hat Mini.
Armed Yes / No. Mirrors the GenMaster arming state via heartbeat. The slave will refuse relay/on commands when disarmed.
Armed At Timestamp the slave's local arm flag was last set true.
State Changes Counter — how many times the relay has flipped since last reboot.
Mock Mode Whether the slave is running with simulated GPIO. Disabled means real hardware.

Failsafe Monitoring

The independent watchdog that protects you if GenMaster goes silent.

Field Meaning
Failsafe Running The watchdog thread is active. Should be Yes at all times.
Last Heartbeat Wall-clock time of the most recent heartbeat received from GenMaster.
Since Heartbeat Seconds since the last heartbeat.
Heartbeat Count Lifetime counter (resets on slave reboot).
Timeout How long the slave will wait without a heartbeat before forcing the relay OFF and (optionally) sending an Apprise alert. Calculated as 3× the GenMaster heartbeat interval — default 30s with the default 10s interval.
Failsafe Triggered If shown, the failsafe has fired since the last reset — clear it manually after diagnosing.

Failsafe is your last line of defense

If GenMaster crashes, loses its database, or its network goes down, the failsafe ensures the generator does not run unattended forever. Don't disable it without good reason.

Network & WiFi

Shows interface configuration for both the LAN/WiFi interface (wlan0) and the Tailscale interface (tailscale0).

For each interface you'll see IP address, netmask, MAC address, default gateway, DNS servers. The WiFi panel additionally shows signal strength (RSSI / percentage) with a Good / Fair / Poor badge.

Action buttons:

  • Add Network — manually enter SSID + password to add a new known WiFi network to the slave's wpa_supplicant config.
  • Scan & Connect — scan for nearby SSIDs and pick one to join.

Sensitive data

The SSID and IP addresses on this panel identify your local network. Mask before sharing externally.

Notification Settings

Click the row to expand. This is the slave's independent notification channel — separate from GenMaster's notifications. It fires when the failsafe trips, ensuring you get alerted even if GenMaster itself is unreachable.

GenSlave — Notification Settings expanded

Field Purpose
Notifications Enabled Master toggle.
Notification Services (Apprise URLs) One or more Apprise URLs (Telegram, Slack, email, ntfy, ...). Format examples: tgram://bottoken/chatid, slack://..., mailto://.... See the Apprise wiki for the full list.
Add Notification URL Adds another row.
Failsafe Cooldown (minutes) Minimum delay between failsafe alerts to avoid flapping. Default 15.
Restored Cooldown (minutes) Same idea for "GenMaster came back" notifications. Default 15.
Save Cooldown Settings Persist the two cooldown values.
Send Test Sends a test notification to all configured URLs. Use after adding a new URL to confirm it works.
Clear cooldown timers Lets the next event fire immediately, ignoring the cooldown.

Scheduled Reboot

A planned maintenance reboot — useful for keeping the slave fresh on long-running deployments.

GenSlave — Scheduled Reboot expanded

Field Purpose
Scheduled Reboot Enabled Master toggle.
Day Day of week (or Daily).
Hour / Minute Time-of-day to reboot (24-hour).
Save Schedule Persist.

Reboots only run when the relay is OFF

GenSlave will skip a scheduled reboot if the generator is currently running. The next attempt will be at the next scheduled time.

Connection Settings

The most sensitive section on this page — it controls how GenMaster talks to GenSlave. Click the row to expand.

GenSlave — Connection Settings expanded

Field Purpose
GenSlave IP Address IP that GenMaster uses. Edit and save to update both ends.
API URL (auto-generated) Read-only — built from the IP and the fixed slave port 8001.
Heartbeat Interval (seconds) How often GenMaster pings the slave with the heartbeat. Default 10 — failsafe trips at 3× this interval (30s by default). Higher = less network noise; lower = faster failsafe.
Current API Secret Hidden by default. Click the eye to reveal, the clipboard to copy.
Change API Secret Type a new secret, or click the dice button to generate a random one. The Save action propagates the new key to both GenMaster and GenSlave at once.

API secret rotation

Both ends MUST use the same key. The Save Settings flow is designed to rotate atomically — but if you ever update the key only on one side, GenMaster will start failing heartbeats and the failsafe will trigger.

Sensitive data

Don't reveal the API secret in any screenshot you share externally.

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