I am working on a high-power Rockerty timing project and only 5 GPIO pins (1 inout and 4 outputs). It has to be very small to fit inside a 53mm tube.
Which Arduino Microcontroller is best to fit the above specifications?
Is that diameter or length ?
Either way, more details needed
what about the esp32-s3-super-mini size 22.52 x 18 mm, 11 digital IO
what are you connecting to the IO pins?
Almost any MCU
The most common example is Attiny85 - SOIC-8, 5x6mm
or even an Atmega328/168/88 in TQFP case - 7x7mm
SEEED Studio XIAO are thumbnail size but full function including one with a camera. Smaller is ATTiny types but with limitations.
Even an overkill Mega 2560 would just about squeeze into a 53-mm ID tube.
As already mentioned, an AtTiny 85 DIP-8 or similar would do the job.
53-mm really isn't small at all, and you could get away with minimal additional hardware.
Look up bare board.
The 53mm is the I.D. This is a booster of a 3-stage bird and almost 2meters tall.
I am hoping I can program and upload with the Arduino IDE
The input GPIO is a burnout sensor, and the other output GPIO is used to fire pyros (staging, smoke bomb, and chute ejection). I use MOSFETs (ZXMS6006DG) to fire the pyros.
Here is what the code might look like:
void loop() {
while (!digitalRead(burnOutSensor)); // Wait for burn out sensor has dected motor burn ou
startTime = millis(); // Rember the time of burn out
digitalWrite(pyro_1, true); // Fire pyro 1 (upper stage)
while(startTime + 750 > millis());
digitalWrite(pyro_1, false); // Turn off pyro 1
while(startTime + 1500 > millis()); // Wait for booster to reach apree
digitalWrite(pyro_2, true); // Fire pyro 2 (booster recovery chute)
digitalWrite(pyro_3, true); // Lite the smoke bomb
while(startTime + 2260 > millis());
// Turn off pyro 2 and pyro 3
digitalWrite(pyro_2, false);
digitalWrite(pyro_3, false);
while(true); // All done so loop constantly.
}
An Attiny85 would do the trick, but you would need another Arduino to program it. An ESP32-XX supermini is probably a better choice.
How do you plan to feed the board and what voltage is the system planned to have? (does the burnout sensor operates either in 5V or 3V3?
Using a 9-volt battery as the power source. Then use a step-down regulator (like LM7805) to power the system. The MOSFETs (ZXMS6006DG) are logic-controlled (either 3V or 5V) gate voltage.
A PP3 by any chance ?
What is PP3?
OK. I learn something every day.
I am using a lithium 9V battery rated at 1200mAh
That is good news because I have lost count of the number of times users have had problems using a PP3 battery designed for use in smoke detectors and other low current applications
I need almost 250mA @ 9V to fire a pyro scrib (e-match). Meaning you're correct, the lithium 9V batteries you buy at the store have only about 800mAh and do not last very long in this type of application. This was a very hard lesson with many failed flights.
This. Even a "full-sized" Arduino Uno is 53mm wide. (did you mean 54mm, BTW?) if you're of a certain age, it's hard to comprehend just how much microcontroller power you can get in a tiny package these days. And so many of the can use Arduino!
You might have trouble trying to fit something that runs Arduino in one of those Apogee 10.5mm minimum diameter models (no longer available, AFAIK), but with HPR your choices are pretty unlimited. (OK, I suppose if you need it to fit in between a 38mm motor mount and a 54mm body tube, things could get tight.)
Batteries and connectors are likely to be the limiting factors.
A "full sized" Arduino Nano or Arduino Micro would fit easily (they're about 18mm wide. 0.7inch)
Adafruit has their QT Py (same size as Xiao), "Itsy-Bitsy", and "Feather"product lines.
Attiny85 is popular, but getting a bit old and is comparatively expensive.
DrAzzy has a number of small boards using newer tiny AVRs.
Microchip has a whole series of "Curiosity Nano" boards
It’s a 3.3 volt device, if that matters.
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