Gemini Enclosure Requirements

e.g. There must be active airflow from 40mm fans towards the Semtech transmitter modules, with at least 20mm clearance above the semtech modules highlighted in orange

Fan is specified here: ELRS Gemini TX

Open

ee - Anni

Heatsinks will be placed on top of the semtech modules.

Active cooling must exist in order to maintain full-power output from the semtech modules.

e.g. There must be mounts for the SMA/RP-SMA side of a U.FL to SMA/RP-SMA adapter in the enclosure

ee - Anni

We will be using u.fl to SMA/RP-SMA pigtails, and we want securely mounted SMA/RP-SMA sides.

< link to pigtail >

e.g. There should be a solid top-face of the case

ee

Protection from top-down rain ingress.

• U2 and U6 (only the coax output in the top left corner, rest can be covered)

  • Correction: Only need an opening for the coax wire to be routed out of the enclosure, exact dimensions should be based on the cable being used but it doesn’t hurt to make it bigger.

• Vent-like openings on the sides of the enclosure near the TX modules

• All connectors/pin headers (J1, J2, J3, J4, J5, J6, J7, P1, P2)

• ESP32 reset button (S1)

• Chip antennas on left/right edge of the board (AE1, AE2)

• The big white status LED near the centre (D1)

Open

ee - @Farris Matar

• U2 and U6 coax cable openings:

  • Antennas shouldn’t be inside the enclosure, so the coax connection needs to be routed out. This would mean the coax cable needs to be connected before enclosure assembled

• Vent-like openings on sides of the enclosure near TX modules:

  • Basically just need some gaps for the hot air to escape when the fans blow on the TX modules. Can be as simple as just a series of holes/extruded cuts along the side walls

• Connectors/pin headers:

  • J1, J3, J5: Openings in the side walls of the enclosure, should be big enough to mate the required cables. Best way to do this is to actually mate cables to those connectors and take measurements of the space needed, otherwise 2-3mm of clearance around the outer bounds of J5 and 1-2mm of clearance around J1, J3 should be enough

  • J2, J4, J6, J7: Openings in the top of the enclosure, at least as large as the black shrouds on the pins + maybe 0.5mm for good measure (to fit jumper wires).

  • P1, P2: If the fans are going to be mounted inside the enclosure, these don’t need to be exposed. Otherwise, expose similar to J2, J4, J6, J7 above.

• Reset button: Ideally enough of an opening to fit a finger in to push the button, otherwise enough to fit a pencil/pen/some easily accessible tool to push the button

• Chip antennas: Opening in either the side next to the antenna or top of the enclosure, about as big as the antenna itself, to reduce potential interference with the antenna

• Big white status LED: Just something big enough to see the LED when looking at the board straight on, it’s fairly bright so it’s fine if there’s a mesh/translucent cover

• Top side Gemini board must be accessible by removing a cover. Similar to RPi case

   

efs - Derek

• Access to header pins

  • programming

  • debugging

• Access to debug probe points

• Access to ESP32 reset button

• Connectors must be directly accessible. Plug and unplug without needing to open anything

  • J1 5V POWER

  • J3 USB FLASH/DEBUG

  • J5 TX16 CONNECTOR

efs - Derek

• Ease of use

  • switch dead batteries

  • update firmware

  • switch EP1/2 device

• Fans can be easily connected with the fan header pins P1/2

  • Image of RPi case fan installation above is a good example

  • Pls no wire surgery with pliers

efs - Derek

• Ease of use

• Antenna access to radio chips mounted at U2 and U6

  • U.FL to SMA adapter can be inserted into the case from the outside

  • The U.FL must be connectable to the radio chips, nothing immovable above the ports, no plier surgery

  • U.FL to SMA adapter will extend from the inside(U.FL side) to the outside(SMA side) of the case, leave hole(s) in wall of case

efs - Derek

• Ease of use

• Big antennas, like the ones on tracking antenna, live outside the case