Hello everyone, i was thinking of making an altimeter to measure the apogee of my rocket and want to build the code from scratch. So, i'm looking for advice before i begin. How do i measure altitude, display it, record it, and the final stage is the PCB lead methods. Any help would be appreciated.
Force times time. bad info. See post #5
After action sketch/program.
Configure a buffer and fill it with data.
Any. One is JLBPCB.
You could probably use a barometer to measure. Displaying the data must be on the ground unless you are in the rocket. Any display will work as long as it can display all the data you want at once. Recording it for hobbyists is usually on a TF card.
You are quite a while from being PCB-ready.
Tell us which altitude you are interested in. The altitude corrected to sea level, or the altitude above your launch location. Do you have some indicator to tell you when the acceleration of the rocket goes to zero so you know when to measure?
Wrong. Fails dimensional analysis.
OP: your goal is often achieved in commercial units with barometric pressure sensors. That would be a good place for you to start self-education.
A popular example: AltimeterOne – Jolly Logic
Oops. Redacted.
(my cross-canceling failed)
Model rocketry enthusiasts solved this problem long ago by combining altimeter and accelerometer data. See attached for an example of such a sensor fusion approach using a Kalman filter.
KalmanApogeeII.pdf (628.8 KB)
or here: GitHub - shohei/apogee-detection
This is somewhat dated. A web search for "model rocketry apogee detection" turns up lots of other examples.
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Have a look at the MS5611 pressure sensor. You can calculate height based on air pressure.
Just don’t know if the sensor works well with rocket speed, so I am interested in your test results.
Is it possible to display the max.height on an OLED screen and once it starts to descends it "freezes" the screen at the max. altitude? yeah PCB will probably be needed 6 months from now. First i want to be able to make a sensor that actually works just by moving my arm up and down to make sure its accurate as possible. Thanks.
Okay i have a question between a BMP280 and a MS5611 pressure sensor, which would you choose. Also how would the rocket speed affect the sensor?
I want altitude from my launch location. As for the indicator i do not have it; what sort of indicators are used to measure acceleration?
A display is a passive device. Anything shown on the display comes from the code driving it, so yes it can be 'frozen' at the max height if that is what the code does.
A sensor sensitive enough to respond to you moving it less than a metre will cost hundreds if not thousands.
Acceleration is in units per second per second.
ahhh, okay i understand thanks. I will try to to focus on both and see which is preferable for the team
That is for you to find out in actual experiments, so use both!
If you're flying a minimum diameter, high thrust model, things will get interesting, barometrically speaking, right around Mach. Expect to see oscillations in the pressure readings.
Also, vent design can potentially cause issues even at lower speeds.
And yet the barometer in my phone registers vertical distances of less than 30cm.
(Hint: My entire phone cost only a few hundred)
Not just any old units. Length units per second per second.
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That's weird, my iPhone doesn't change at all over that distance and it cost way to muckin futch.