9/22/24
Telemega:
Tried to connect to AltOS using teledongle. Teledongle is necessary to connect, as is closed switch connecting two switch terminals. We were unable to successfully use the TeleMega but it did turn on.
Blue Raven:
Tried to "fire" the LEDs on BlueRaven board. Discovered low battery voltage and replaced battery. Used multimeter to measure voltages across outputs and found no response to app fires.
10/13/24
Where we're at:
Computers
We've decided to ditch the Blue Raven as it was annoying to work with (mobile app only instead of a pc app) and also didn't work. We tried for a while to understand why it didn't behave as we were expecting but ultimately couldn't figure it out.
Instead, we're going with 2 TeleMegas. This did raise concerns about the two TeleMega antennas interfering with one another. Based on the principle that the antennas should be at least 1/4 wavelength apart, we decided that the minimum distance between the antennas should be 6.8". The only way to achieve this would be to separate the antennas vertically as the inner diameter of the MPT is only 6". That's why we decided to move Avionics up into the nose cone, so that we could utilize that space to separate the antennas.
We're planning on powering each TeleMega with a 900mAh LiPo from Altus Metrum. Spaceport has restrictions prohibiting the use of LiPo batteries except in cases where the battery is "recommended and supplied by the manufacturer"
6.20.1 Lithium-Polymer (LiPo) batteries are not permitted due to fire hazard unless installed
in the powered device by the manufacturer or recommended and supplied by the
manufacturer. (SA_Cup_DTEG_v2.2.9)
it is clarified in HeroX that using a LiPo from Altus Metrum with a TeleMega is permitted.
Cameras
We need to power two cameras, one pointing up at the nose cone and one pointing down at recovery and the motor. We will have each of the cameras write to an SD card while on so that we can pull the footage off of them after flight (obviously). We also decided that we would like to have live transmission from the downward-facing camera in flight.
Two options for camera transmission signal: 1.3 GHZ & 5.8 GHZ
1.3 GHz pros:
- easier to get a longer range
- passes through obstacles well
1.3 GHz cons:
- Big antenna
- Interferes with GPS
5.8 GHz pros:
- smaller antenna
- more commercialized
5.8GHz cons:
- harder to get longer range
- doesn't pass through obstacles well
We decided to go with 5.8GHz as we care more about it not interfering with GPS than we do about long range, the camera will write to the SD either way, so if we loose transmission in flight it's not that big of a deal.
Cable for converting: Analog video to USB: https://www.amazon.com/Converter-Digital-Capture-Digitize-Windows/dp/B08C9T5M37/
Option for antenna: https://www.amazon.com/Foxeer-Antenna-Lollipop-Quadcopeter-Multicopter/dp/B07D12XS6K/
Option for receiver: https://www.amazon.com/Wolfwhoop-WR832-Wireless-Receiver-Multicopter/dp/B01H36AIGY/
Option for transmitter: https://www.amazon.com/HGLRC-Transmission-Adjustable-Aerial-Photography/dp/B0CX8MRH2C/
Option for camera: https://shop.runcam.com/runcam-mini-fpv-dvr/