AVA Flight Computer for Model Rockets Is Beautiful and Functional
Joe Barnard's design is based on Arduino-compatible MCUs and off-the-shelf sensors.
With the flight controllers from BPS.space, you can build model rockets that can land! Run by Joe Barnard, the latest BPS.space flight computer is AVA, short for All Vehicle Avionics. AVA's introduction not only informative but also beautifully shot, and worth a watch even if you are not into rockets.
For clarity, the BPS.space website explains the distinction between guidance and stability.
"The Signal flight computer doesn’t provide any guidance capabilities, just stability. Guidance is usually about maneuvering in reference to one or more real points in space. This might be via GPS, GLONASS, RF, or even dead reckoning. Stability is just about keeping the rocket upright, which serves the same purpose as fins on a traditional model rocket."
Anyone familiar with 32-bit Arduino boards will instantly recognize several of the processors used in AVA's design. For example, the core microprocessor is the name NXP Kinetis K20 found in PJRC's Teensy 3.2. Barnard chose the Microchip SAM D21 for both the navigation and telemetry processors. These popular Arm Cortex-M0+ processors in 32-bit Arduino boards and BPS.space uses them in their other products.
AVA has a variety of on-board sensors. A u-blox ZOE-M8Q provides GPS, or global navigation satellite system (GNSS), data. Most GNSS receiver options are serial or UART based, which means processing strings to communicate with a microcontroller. An attractive and refreshing feature of the M8Q is that it communicates with the host processor over I2C!
There are two inertial measurement units (IMUs) in AVA. The first one is the popular BNO055 from Bosch. Barnard mentions this particular IMU is not a great fit. It is not because of the sensor's (otherwise excellent) capabilities, but because AVA does not use its sensor fusion features. A secondary IMU provides logging data as a backup. Barometric pressure measurements come from a TE MS5611, which is accurate for high altitudes where other data sources are not available.
Barnard selected a Rohm KX134 high-g accelerometer. This particular sensor is capable of measuring ±64g. While none of BPS.space's (planned) experiments require that much force, some will require more than the other sensors' typical ±16g capability.
Outside of the model rocketry hobby, the AVA introduction video showcases beautiful soldering shots of the surface mount components. Even the video's section on the silicon conformal coat has an artistic flare while also providing some instruction. If you are not into the flight computer aspect, you might enjoy the video's production and education elements.
Check out the AVA Flight Computer introduction video on the BPS.space YouTube channel. While watching, see if you can spot the board error. You might also want to check out the BPS.space website if you're interested in other electronics for model rockets.