Parachute Deployment Project Recommendation

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).

  1. Do these parts sound adequate?

  2. Do i have to have a breadboard?

  3. 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...)

UNO? Too big. You want the smallest board available.

Breadboard? Too big and unreliable. You need to solder all connections.

What parameter are you going to measure to give you the trigger for deploying the chute?

John.

Won’t the acceleration readings show negative values for the z-axis after its reached apogee? Then use that?

So check the z-axis acceleration every ~500ms, and when it turns negative, release the parachute…

Yes, I suppose so.

What about a GPS module that could record the trip?

John.

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.

Could the nosecone be designed to stay in place during ascent and fall away at descent? If the chute is housed behind the nosecone it would deploy.

NissanCedric:
What about a GPS module that could record the trip?

Depends on the speed, heigh and acceleration of the rocket.

Ask for guidance in a rocket forum as to which works best, if at all.

Standard GPSs have built in restrictions to stop them being used in missiles etc.

Is it known what parameters are used to inhibit GPS use in rockets/missiles?

I've seen a youtube that said it was altitude (extreme altitude).

Toby, what is the expected max altitude of your rocket?

John.

NissanCedric:
Is it known what parameters are used to inhibit GPS use in rockets/missiles?

Normally listed in the datasheet for the GPS.

Is it likely Toby's rocket will be seen as a missile by an on-board GPS?

That in itself is a project. Fire the rocket and see what the GPS records.

A timer could provide a backup trigger mechanism.

John.

NissanCedric:
Yes, I suppose so.

What about a GPS module that could record the trip?

John.

Lets keep things simple for now lol. But i might look into doing that once i've got this sorted.

NissanCedric:
Is it known what parameters are used to inhibit GPS use in rockets/missiles?

I've seen a youtube that said it was altitude (extreme altitude).

Toby, what is the expected max altitude of your rocket?

John.

Approximately 5km

GPS is simple to the end user.

It provides altitude and speed that you could use to trigger the chute.

John.

5km. What's that in feet? About 17,000?

Planes fly higher and they use GPS.

What will this rocket do in its flight? Record data or pics?

John.

TobyT:
Approximately 5km

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.

NissanCedric:
5km. What’s that in feet? About 17,000?

Planes fly higher and they use GPS.

What will this rocket do in its flight? Record data or pics?

John.

Just record some data, probably wont be taking pictures.

Toby,

Are we helping? (-:

John.

NissanCedric:
Toby,

Are we helping? (-:

John.

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...

Thanks for all the help

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.

John.