Jump Jet is a PCBWay-sponsored chamber-heater project for the Prusa CORE One family, developed by Dan and Mauker. It redesigns the electronics and firmware of Philip Sørensen's original Jetpack project while retaining its practical, printer-integrated form factor.
Development status: cold-safe foundation. The production firmware has no heater or fan GPIO, PWM, ADC, thermistor conversion, or actuator driver. It cannot energize a heater and is not installable heater-control firmware.
Jump Jet began as a fork of Philip Sørensen's
esp32-chamber-heater-core-one.
Philip created the original mechanical concept, Arduino firmware, PrusaLink
automation, PID approach, and three-sensor safety concept. The retained history
and legacy source remain GPL-3.0. See UPSTREAM.md for provenance.
The new firmware is a distinct ESP-IDF/Dragon-family product. It consumes pinned,
board-neutral services from dragon-core
while keeping product policy, hardware, control, settings, API behavior, and all
heater safety decisions local to Jump Jet.
- ESP32-S3 ESP-IDF application skeleton
dc_wifi,dc_portal,dc_ui,dc_evlog, and read-onlydc_prusapinned to dragon-core v0.32.0 (4e041d864763d468a50e9649807827dd83dd54bc)- exactly three product modes: OFF, MANUAL, and AUTOMATIC; boot/reset is always OFF
- manual target policy of 30–50 °C inclusive with a 45 °C default and rejection, never clamping, outside that range
dc_prusa's existing 15-second freshness result used directly, with no second Jump Jet freshness timer- whitelist-only AUTOMATIC eligibility: only exact
PRINTINGis eligible, and production automatic heat remains unavailable until the bed-target mapping is defined - truthful read-only API diagnostics and capabilities
- pre-upload and immediate pre-boot-selection OTA thermal-state guards
- host tests, API/static contract checks, UBSan, and ESP32-S3 CI build
- no heater or fan actuation path
The authoritative product and safety behavior is defined in the product/safety contract.
Standalone CZ4060 characterization measured about 189 W / 7.89 A sustained at 24 V, no high-current cold inrush, about 130 °C at the heater/PTC region, and about 74–75 °C at the chassis. Design sizing remains the rated 24 V / 200 W / 8.33 A case.
That test did not validate the complete Jump Jet Q1/F2/PCB/connector/wiring
path or installed operation. The authoritative .kicad_pcb is still missing.
GPIO, ADC, thermistor, protection, and cooldown thresholds therefore remain TBD.
The Sanyo Denki 9GA0424P3J001 is only a prototype fan candidate, not BOM-final.
Firmware is only one layer. A release also requires rated wiring/connectors, input protection and fusing, an independent thermal cutoff, a derated MOSFET, appropriate PCB copper and clearances, proven airflow, suitable materials, and fault-injection evidence. The browser and API are never the safety boundary.
./tests/run_interlock_host_test.sh
sh tests/check_identity_contract.sh
sh tests/check_api_contract.sh
sh tests/check_actuation_allowlist.sh
sh tests/check_ota_contract.shFor ESP-IDF 5.3 or newer:
./tools/idf-build.sh . esp32s3- Product and safety contract
- Firmware architecture
- Hardware baseline
- CZ4060 characterization
- Safety verification
- Roadmap and work queue
- Migration map
- Attribution and provenance
- Dan — project, firmware, and hardware
- Mauker — project and mechanical design
- Original Jetpack project: Philip Sørensen
- PCB fabrication sponsored by PCBWay
Jump Jet is independent and is not affiliated with or endorsed by Prusa Research or the original Jetpack author.
GPL-3.0, inherited from the upstream Jetpack repository. dragon-core is consumed
as an MIT-licensed dependency.