Assume i'm completely new to programming and electronics in general.
I'm building a model rocket from scratch, which means i need a parachute to deploy just after the rockets has reached apogee.
I was thinking about getting an Aduino UNO and a Adafruit Triple-Axis Accelerometer (MMA8451).
Do these parts sound adequate?
Do i have to have a breadboard?
Whats the best way to ignite black powder from an electrical signal? (My idea was send some current along a really thin wire and let it get hot enough to ignite the black powder, but that sounds too crude...)
Use the smallest Arduino that can work with the MMA8451
a DigiSpark
an ESP8285 bare board
there are many others.
you can program with an UNO/NANO or specialty USB programmer.
There are firework fuses. thin wires with stuff like the head of a match.
power through the wire and the chemicals light.
Amazon, lots for cheap. like 20 for $2.
The acceleration in the z-direction (actually, any direction) will drop to a very small number the moment the motor runs out. That "very small number" is the air resistance your rocket has. In a perfect vacuum and the motor not smoking or otherwise expelling minor bits of matter it'd be exactly zero.
Within the atmosphere, at apogee it should drop to zero as your air speed is zero, but very likely this part of the signal is drowning in the noise (tumbling of the rocket, wind, etc).
A possibly better approach is an altimeter, and when you detect it stops rising and starts to go down you have passed the apogee.
I'm sure there are commercial solutions to safely detonate your black powder. Probably simply a thin wire that burns when you run current through it.
For board, depending on how much your rocket can carry a Pro Mini would be a good solution, at least you can just leave out the headers and solder wires directly to it. If that's still too big/heavy you can shrink down even more by using an ATtiny on custom PCB.
That is no problem for a regular pressure sensor, such as a BMP280. Cheap, small, and accurate. That altitude also means you have ample time to deploy the chute, so you can trigger when measuring a significant increase in air pressure meaning you're falling.
No idea how that sensor reacts to the strong acceleration of the rocket motor firing, I can imagine it gives wrong readings during that period. You know how long the rocket motor burns so it's easy enough to ignore that period.
Lol yes yes, i'm taking everything on board. Someone suggested an altitude meter, which sounds easier i think, for parachute deployment, since its either going up or down. Accelerometer can be used for some data. GPS i never thought about, but i guess that would be useful for more data, but not a priority quite yet...
GPS would give you altitude and speed for the entire trip. If you recorded it to an SD card you could then replay the trip on your PC. Assuming you can retrieve your rocket.