I'm doing some testing on parachutes and want to record descent rate. Is there a way to do this with say, a cube, without going to a pitot tube? I would think that the angular descent of a parachute would not give accurate descent rate (or would it?) due to the lateral motion. Does the cube have an RTC to record the samples by time along with the other sensors, so I could calculate speed over time? How about an add-on to a cube (a la arduino shield) to do the airspeed descent rate. I'm comparing designs and sizes of chutes. Would like as accurate of info as is cost effective. I'd want to log it onboard, to negate the need for telemetry.
I ordered that equipment. Having a time finding a 5v lipo (flat).
Ken Wilkins said:
Thanks for the specifics. I'm using circuit.io for wiring diagram. They don't have the radio link, though, so how should I wire it, and what do I need on the ground for it?
Thank you all ! This is good info. As I'm reading these, I'm watching a vid of Limor Fried. hehe.. Thank you again!
you could easily do this with an arduino [nano/micro/whatever] + SD reader + MPL3115A2. If you wanted to also beam down the data in realtime you could also use a set of radios. Total cost [if buying from ebay] would be about 10 bucks. [20ish if you wanted to use a couple of radios as well] if you needed accurate time measurememt you could also just add a RTC module as well.
DS1302 Clock https://www.ebay.com/itm/DS1302-Clock-Module-with-Battery-Real-Time...
SPI Reader Micro SD Memory Card https://www.ebay.com/itm/SPI-Reader-Micro-SD-Memory-Card-TF-Memory-...
Arduino nano https://www.ebay.com/itm/Nano-V3-0-Mini-USB-ATmega328-5V-16M-Micro-...
Radio Link https://www.ebay.com/itm/2pcs-433Mhz-Radio-Link-RF-transmitter-Rece...
all you need to do is look at the logs.... read the alt vs the time line.
But rather than trying to measure decent 'rates' all that is really important is the final Z vib (and x and y to a lesser degree) shock value as it hits the ground!
I was wanting a small size solution. THe Pi may be too big.
Thanks for the info. I do have a Pi3. May do that. I'd have to figure out the programming.