Ground Station Electrical Notes

Owned by Yevgeniy Gorbachev (RIT Student)
Last updated: Feb 01, 2022 by Will Merges (RIT Student)

The internal components (under the bottom plate) of the ground station include:

  • 3x LattePanda SoCs
  • 12V converter
  • 5V converter

The components that must be mounted on the bottom plate for the user to access include:

  • 3x Ethernet ports (female)
    • Easiest to use Male-to-Female adapter and mount female end to plate
  • 1x 2.5mm Audio Jack
  • 1x Custom Altitude Gauge
    • Custom servo controlled gauge controlled by PWM from one of the LattePanda's onboard Arduinos
  • 6x USB out
    • At least 2 USB outputs per LattePanda
  • HDMI Passthrough
    • The HDMI cable must be able to pass from the top plate to the bottom plate, there is no connector for this currently although one could be added
      • We've done HDMI over RJ45 in the past, it worked but is a nightmare to use reliably
  • 5V display power
    • Similar to the HDMI passthrough, a 5V line needs to be passed to the top plate for the display
  • SPDT Switch (Single Pole Double Throw)
    • Selects which of the power inputs to use
    • Needed for startup and hotswapping
  • 2x Fans
    • 12V fans for cooling
      • One blows, one sucks
  • 2x SPST Switch (Single Pole Single Throw)
    • Toggles whether each fan is powered
  • 5V Output
    • Female Barrel jack to power the externally mounted router
  • 20V Input
    • Female Barrel jack to take input from external batteries

The top plate only contains the display.

The router will be mounted externally (velcro on the back of the case) and needs power from the 5V barrel jack. All of the LattePanda Ethernet outputs should be plugged into the router.

The batteries will be external to the case and plugged in through the 20V barrel jacks.


Hotswap Procedure

Assuming one battery is already plugged in and powering the system.

  • Plug in the second battery to the open power input barrel
  • Turn on the second battery (if applicable)
  • Flip the SPDT switch
  • Unplug the old battery

Initial Power Up

Very similar to the hotswap procedure but with no initial battery.

  • Plug in the battery to a power input barrel
  • Throw the SPDT switch so the OTHER power input is selected (e.g. the input the battery is on is disconnected)
  • Turn on the battery
  • Throw the SPDT switch to select the power input from the battery

This procedure assumes the battery has load detection and low power shutdown protection. If that is not the case, simply plug the battery in and select the power input with the SPDT switch in any order.