Lost AC Beacon Project

[Dronion]

This is my Lost AC beacon project.
This project is still in development state.


Specifications:

Dual 10000 mcd leds, dual piezo buzzers, 433.92 mhz radio transmitter, 50 grams with batteries, user selectable mode ofoperation by single button: Standby Silent mode, standby strobo mode, standby strobo + audio beep mode.
This is a prototype so the dimensions and weight are much more greater than an eventual production version of the device.
Hardware and software are designed by me.

The radio transmission starts after a specified number of standby minutes, sending a signal with the duration of 0,5 second every second.
The beacon heart is a microcontroller, powered by two CR2032 button cells. It incorporates an high precision timer.
The firmware is updatable in its flash memory.
Radio module is shut down during standby mode to avoid interferences with AC flight controller.
Audio signals are generated by two piezo buzzers with no magnetic parts to avoid interferences with AC compasses.
Actually the beacon is set up with 30 minutes standby timer. (because of the 27 minutes of the battery duration of my mavic)
The device is equipped with two rx/tx serial port pins (physically not yet implemented, i need to solder them on themotherboard) that can be connected to a computer via a TTL serial to USB cable.
User will be able to modify the parameters of operation of the beacon thru a standard text console interface, standby time,strobo, audio and radio delays, duration of strobo, audio and radio signals etc. This function is not available on the actualfirmware version, i'm writing the firmware code to implement it!

The beacon provides a battery low indicator. The microcontroller measures the battery charge at startup.

Radio signals can be received using a SDR-RTL usb dongle connected to a smartphone with an otg cable, or with a simple portable hf ham radio. The strength of the received signal will help you get closer to the lost AC, with the help of audio and strobo signals at the same time.

I hope you like this project.

Thanks.

 

[PT_Mavic]

An interesting design; what are the dimensions and weight?

The audio beeper is a nice improvement, but I'm already using the Marco Polo tracker on my Mavic - although it has no audio beeper, the radio transmitter on it lasts several DAYS for extended tracking if necessary, and is uses a form of Doppler reception to create a direction indicator on the palm-sized tracker, pointing to the Mavic, so an audio signal isn't strictly necessary to home in on it.

 

[Dronion]

An interesting design; what are the dimensions and weight?

The audio beeper is a nice improvement, but I'm already using the Marco Polo tracker on my Mavic - although it has no audio beeper, the radio transmitter on it lasts several DAYS for extended tracking if necessary, and is uses a form of Doppler reception to create a direction indicator on the palm-sized tracker, pointing to the Mavic, so an audio signal isn't strictly necessary to home in on it.

Dimensions 6x4x2.1 cm
Weight about 50 grams

 

[richardhurst]

I like the concept but I'd be worried that if i'm trying to locate it myself the audio and strobe signals may bring it to the attention to the people who may find it first and not return it

 

[Dronion]

I like the concept but I'd be worried that if i'm trying to locate it myself the audio and strobe signals may bring it to the attention to the people who may find it first and not return it

Audio and strobo signals can be disabled eventually. I will implement this function.

Thanks