Firmware Dongle v9

Dongle firmware v9

Released	2026-05
Status	Superseded by v10
Pairs with receiver	v9+
Predecessor	v8 (no formal notes)

Downloads

File	Purpose	Download
os4_dongle_v9.bin	App partition.	Download
os4_dongle_v9.bootloader.bin	Chip bootloader.	Download
os4_dongle_v9.partitions.bin	Partition table.	Download
os4_dongle_v9.boot_app0.bin	OTA "next-app" pointer.	Download

Release notes

Clamp clockSyncIntervalMs + scrub queue on forget.

• Config knobs clock_sync_interval_ms / response_timeout_ms / receiver_timeout_ms are now sanity-bounded on apply (50..30000 ms, 5..500 ms, 60 s..6 h respectively). Out-of-range values silently broke polling — e.g. setting csim=0 made pollSpacingMs=0 then 5 ms-floored, which busted ACK timing on slow links. The actually-applied values get echoed back in the per-second status as csim so the host UI can show what the dongle is running with.
• forget IDENT now removes any pending queued commands targeting that nodeID. Previously a forgotten receiver would still get any in-flight queued commands dispatched, wasting up to ~22 ms of radio time per cmd on TX-FAIL retries.

Upgrade notes

• No wire-protocol break.
• Worth pairing with receiver FW v9+ — receivers older than that can't talk this dongle's ACK-payload protocol regardless.

How to flash

• Flashing a dongle.