How to Use Ginger

So, you have a box of ginger and you want to make it go… (photos to come)

  • Note: The order of these steps isn't important, but it makes for a clean startup

Know what you can and can't do (in order of consequences)

  1. NEVER attempt to apply power to the amplifier without an antenna or dummy load attached. All of the power will be reflected back into the amplifier and cause it to burn out.
  2. Don't apply a battery to Ginger Prime's digital supply pins. The digital power is supplied by the USB bus unless the board is modified (and there are no plans to do this). The amplifier power supply pins reside within the amplifier subsection of the clearly marked PCB.
  3. Always modify and verify the downlink parameters first. This way, if the link is broken by the modification you can still adjust them through the downlink or issue a reset command. Once the downlink is locked, carefuly adjust the uplink. It might be best to keep the uplink at the defaults unless there is a good reason to do otherwise.
  4. Don't mix up the digital supply and the amplifier supply pins. Actually, its probably fine. But… you should be paying more attention!
  5. Make sure that the coax bridge is in place before applying power to the amplifier or nothing will come out.
  6. Don't leave the amplifier battery plugged in, a small leakage current is drawn (especially in the V1 PCB) and this will drain the battery.
  7. Don't be careless and place to RX and TX frequencies at the same spot. If the packets coming from ginger repeat endlessly, change the channel by a small amount as certain combinations can result in intermodulation (The reciever is hearing the transmitter through a multiple of the IF frequency)
  8. BUG ALERT. There is a hardware bug which cannot handle large channel changes. 'Work' your way to the new frequency by ~1MHz or less increments and verify each change by requesting telemetry.

Inventory

  1. Ginger Prime and its clear plastic case.
  2. Ginger and its capsule
  3. Remove for Flight tag and molex receptacle
  4. 500-800 mAH lithium cell to power Ginger
  5. Three-cell lithium pack to power Ginger's Amplifier
  6. USB cord with USB-mini connector to power/interface with Ginger Prime
  7. Access to a car battery or eq to power Ginger Prime's amplifier
  8. Cig-lighter to molex cord for 12V power.
  9. Antennas and coax for ground
  10. Antennas and coax for capsule
  11. Allspice Nodes and batteries (if not supplied with power from host)

1 Pre-Flight Setp

  1. The software is available on the spicerack page.
  2. Extract everything to a folder on your desktop
  • The morning of the launch,
    1. Connect the amplifier battery pack to Ginger's amplifier molex terminal
    2. Insert a bright red "Remove for Flight" tag if not already present
    3. Attach a single lithium cell to the main power terminal if not already present
    4. Assure that the coaxial bridge is in place, tighten the SMA connectors with a wrench (but don't break the board)
    5. Assure that all antennas are in place, tighten the SMA connectors with a wrench (but don't break the board)
    6. Close the capsule securely as you will not longer need to open it

2 Run the software

  1. Run Spicerack.exe. (If it crashes repeatedly, please contact Jasper_Nance via email or phone in an emergency)
  • There should be a bright red bar at the bottom of the screen which informs you that Ginger Prime is not connected
  • All data will be stored in a subdirectory of the execution directory having the format ./yyyyMMdd/hhmmSS/ with a new directory created each time the program is run.

3 Plug in Ginger Prime

  1. Ginger prime has a USB plug and a long USB cable should be in the box. The circuit is powered over the USB bus. The green LED should light and the red bar at the bottom of the Spicerack should dissapear. Each chip will blink its red LED briefly, this indicates successful bootup. If this does not happen and you are prompted for drivers, please point windows to the included "drivers" subfolder.
  2. To test the link, press the "Get Telems" button. If you do not see a response from GPR and a nice blinking of lights, something is not working correctly. Without closing the software, unplug and re-plug the USB cord to cycle power and try again.
  3. Apply power to the amplifier's molex connector (12v lead acid car battery) in between transmitting.
  4. It is a good idea to check the "auto telem" box. This will ping the chips every 10 seconds for telemetry information.

4 Apply Power to Ginger

  1. If you are JUST TESTING, do not apply power to the amplifier, you will only waste power and if the hardware is too close the signal will overload the receivers.
  2. If the FLIGHT IS FOR REAL apply power to the amplifier before leaving the ground-station. The amplifier will sit in standby mode until you drive out and set up. It will be fine for a few hours. (The green 3 x 3.7V lithium-polymer pack)
  3. …And remove the "Remove for flight tag"
  4. You should see the green LED light turn on (uhm, unless the capsule is closed). Each chip will blink its red LED briefly, this indicates successful bootup.
  5. Check for successful telemetry in the Spicerack by either waiting for the auto telem timer, or by pressing the telems button.

5 Adjust Link Parameters

  1. Open the radio control module for this.
    • If the data is coming in slowly, the default of 1.2kbps will work.
    • If you need more than a 1Hz packet rate you can change the downlink to 38.4kbps.
      1. Use the drop down menu to select 38.4kbps for the downlink.
      2. Press 'apply' to send the change of channel command.
      3. Verify the change by requesting telemetry.
        • There is a bug where the uplink rate may not change correctly for the ground transmitter. You can try querying the GPT chip by sending "GPT:GND rate". If you receive "GND:GPT rate is 12", you can change the chip manually by issuing "GPT:GND rate=384". GPT is currently the only chip that has this problem.
      4. If the link appears broken it is possible that the packets were corrupted on the way, press the 'apply' button again to resend the change channel command. This may be necessary if the link is strained.
    • Leaving the uplink at 1.2kbps is a good idea. That way, if the data rate on the downlink is too high (and the signal is too weak) you can still slow down the downlink and send emergency commands.

6 Remove the 'Remove for Flight' tags from the allspice nodes, or turn them on via the appropriate battery connections.

  1. You should see the data coming in through the RX window of the SpiceRack. If there is a large amount of data it can be difficult to eyeball. You should open the appropriate modules at this point to view the data graphically.
  2. If all seems well, go ahead and begin the flight!

What telemetry is gathered by the auto timer?

  • Currently there are three things that are gathered (subject to change!)
    1. Uplink parameters (noise and received signal strength)
    2. Ginger's single cell battery voltage
    3. Downlink parameters (noise and received signal strength)
  • These are plotted in the telemetry module

7 Awesome flight! Now don't just leave it running!

  1. Insert main 'remove for flight' tag. Remove all batteries from allspice nodes (or otherwise power down).
  2. Drive home
  3. Do NOT just leave it sitting in the hamshack, please disconnect ALL batteries and check their state of health. If below 1V per cell recharge immediately. if below 3V go home and recharge some time later. If above 3V recharge before next flight (leaving the battery is a discharged state is actually good for it!).