2023-09-26 COTS clarifications and priorities
- Aaditya Chaudhary
Priorities
Gemini
CAN sensor board & RTK support
other random projects?
lighting control
OSD
support for individual sensors
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Gemini - End of Fall Term
Most important thing
First board by end of Oct
all control and telem links will run through this for forseeable future
ELRS
express LRS
wireless transmission protocol
really good long range performance
high speed control
open source
started as a racing control link
added support for mavlink, support for serial uart link
gemini is an addition to elrs which transmits the same packet over 2 different frequencies
helps with avoiding interference and lets us have more control with antenna setups
fw exists as open source
things we can add
more than 2 frequencies
better control
we want our controller (tx16) to work with gemini
Gemini control board is on tracking antenna
tx16 uses crsf (crossfire)
400k baudrate
controller communicates with 420k baud
figure out how to flash to gemini and output our crsf at the correct baudrate
2 wireless links
tx16 pairs with elrs rx over wireless elrs using the internal elrs module of the tx16
gemini tx on the tracking antenna to the gemini rx on the drone
we need to bridge the elrs rx to the gemini groundside board using UART
Tasks
understanding the transmission modes of elrs
figuring out what baudrates are available
configuring the baudrate we choose and flash
more features
better MAVLINK streaming support
currently it does bytes in bytes out
bandwidth at lower frequencies isnt enough for both control and telem with bytes in bytes out
integrating it into ZP ecosystem
attaching a GPS to pwm recievers to get location
SBUS and pwm outputs
RTK GPS - By end of Comp have it flight tested
ardupilot has a list of supported GPS that communicate using NMEA protocol
we can potentially consider this cycle if its been proven flight tested by november, but thats unlikely
doing RTK on supported GPS costs a lot
only 5 or 6 GPS that ardu supports and they are expensive
RTK capable GPS are cheaper on sparkfun and are better
Figure out what GPS we could use and how theyre better than what we have right now,
RTK
GNSS vs GPS
how many antenna
RTK uses base stations to get very high accuracy GPS readings
the reason GPS isnt very accurate is because the ionosphere changes, so using a base station lets you find ionosphere corrections and you can apply it to drone location
GPS correction data formats - check in mavlink?
ardupilot uses a particular gps correction format
submit corrections over mavlink and ardupilot driver would unpack that and send it to the RTK capable GPS
driver basically converts correction data from MAVLINk to whatever format the GPS uses
tasks
research what all these terms mean
what can be used as a base station
make an arch doc
research what family of GPS to use (use the same protocol)
cheap stuff, expensive stuff,
long term what family do we want to invest our development time into
feel out what the space is like
get a gps
write ardupilot snf mission planner driver for it
https://navspark.mybigcommerce.com/ns-hp-gn5-px1125r-l1-l5-rtk-breakout-board/
CAN sensor board - Summary Of findings by feb/march (using nucleo and wires) (wait for arch meeting)
family of boards and sensors
lots of off the shelf sensors are ugly and use protocols like i2c and uart and spi that cant be easily networked
take a small chip like an f0 that can interface with the sensor and connect to a CAN network
still in arch phase
still up in air exactly
one board is sensor + f0
on board has a bunch of sensors on it + a beefier chip
OFS
range finder
figure out
need to figure out what chip can do CAN,
what sensors we want to support,
dont support sensors that are near EOL
how to communicate with ardu using CAN
dronecan has support but others might be better
how to pack sensor data together
how to send sensor data that isnt necessarily supported by ardu
might require some ardupilot driver
coding
write generic driver for the CAN side
create a collection of existing sensor drivers that we either already have or will write
failure scenarios and protections
lighting for Ardu POC on ground by end of fall term)
kinds of lights
strobe lights
nav lights
taxi lights
beacon
DJI drones
rgb on all 4 sides
change to indicate state, direction etc
software support for changing
might be a separate board with f0 to control that
might be an ardupilot driver
ardu doesnt support mixed lighting modes
how we should light our aircraft to make it safe at night
look up the law
look up common methods and standards used in cots drones
degrees of visibility when putting a light on the drone
all for exterior ^
interior
emergency lighting in airplanes
car door lights
make it so that in ardupilot, some action will trigger lights,
when you land turn off external and turn on cabin lights
dim cabin lights
realism
hw
select a part and ee makes a custom board
buy a cots board
do some research on neopixels vs rgb vs whatever and ask for input
OSD (summary of findings by feb/march)
exists between camera and tx
overlays mavlink information onto the video feed
EE had trouble sourcing a chip for OSD
potentially works with ST chip
research and proof of concept project
if it goes well, ask EE to help and make this a formal project
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Support for individual sensors (POC of rplidar A1 by early dec)
lots of sensors dont have support but are cheaper than ones that do
ties in with CAN sensor board
sensors
RPLidar A1 and A2
any lidar that they have at robohub
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