This page is written after LC 2024.

Short History of VLF4

There are two revision of VLF4: VLF4 r1 and VLF4 r2.

VLF4 r1 is designed between July and August 2023 (after SAC 2023), and manufactured in September 2023. 10 pieces of PCBs were made and 5 of them were assembled (by JLCPCB).

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VLF4 r2 is designed in May 2024 (before SAC 2024). The main purposes of r2 are:

• Replenish the usable avionics (VLF4 r1 SN1 and SN2 are already none functional)
• Fix the placement of SWD connector. The SWD connector on r1 is blocked when the antenna is installed. (r2 has one less buzzer to leave space to the SWD connector)
• Optimize sensor placements

VLF4 r2 kept the power supply and pyro routing, and rerouted everything else. 20 pieces of PCBs were made and 10 of them were assembled (by JLCPCB). VLF4 r2 is used on both Luminis (2024 SAC) and Luminis V2 (2024 LC). Half of the VLF4 r2 along with all the assembled VLF4 r1 are lost in the 2024 LC crate.

VLF4 r2 are not in the avionics database yet, but they should either be in hatch bay or in the lost crate.

Cost

A complete VLF4 r2 costs around 100 CAD each. This is significantly lower than other COTS solutions (Blue Raven costs 175 USD each). With higher boards per batch (e.g. 20pcs), the cost is somewhere around 80CAD. But VLF4 requires complex manual assembly, which takes considerably amount of time.

Assembly

1. Manually solder any components JLCPCB doesn’t have (molex connectors, SMA connector, E22 for r1, GPS for r2)
2. Apply epoxy to secure E22 to the board
3. Wait a day for epoxy to cure
4. Put the heat sink on the back of E22
5. Put top and bottom PCB together with spacers in between
6. Use electrical tape to cover the through holes on the bottom PCB