This is an Arduino based wireless buzzer system. Scroll down for the code, circuit diagrams, Fusion360 files, STL files, Cura profiles (settings) and G-Codes for 3D printing the enclosures.
If you are interested in our work or product, please e-mail: flute.systems@outlook.com, flutesys@gmail.com
We are immensely grateful to the following for their excellent resources that made this project possible: Google, The Arduino Project - Community - Forum, Adafruit, Sparkfun, Autodesk Fusion 360, Hackaday, Ultimaker Cura and Prusa Research. Mr. Andreas Spiess (Youtube). Dave Jones [EEVBlog]. Mike Dane (Giraffe Academy). Thomas Sanladerer (Youtube). Special Thanks to [maniacbug], [TMRh20] and all contributors of the excellent RF24 library which this project hinges on. Avishay Orpaz for the TM1637 display library. Immense gratitude to the PlatformIO project and Microsoft's VSCode. To Dr. Annappa Kamath from Mangalore for commissioning this project + His patience and support. Quizbeleving.nl is our Unique and Exemplary client, we are very grateful for their trust, involvement and all their support.
Range with the basic nRF24L01 module shown here is minimum 30 metres in open air. One concrete wall reduces this to around 10 metres). The nRF24L01 [PA+LNA] module is drop-in replaceable, increases range and sensitivity.
Small 150mAh LiPo batteries in the buzzers last for at least 4-5 hours with the current setup.
The next video shows repeat presses being ignored :
Fast presses :
Buzzer enclosure - open/close with a half-turn :
Base Station :
Base station uses Arduino Pro Mini 5V. The reason for having 5V in this circuit is the TM1637 7-segment display. 5V active buzzer module. Adafruit PowerBoost 1000C for 5V and green Pololu switch mode voltage regulator board for 3.3V for the radio module. The Base Station runs for at least 5 hours off a 2000 mAh LiPo battery.
Temporary solution for recharging the buzzer unit LiPo batteries: TP4056 modules with resistor R2 on Pin2 replaced with 10 KOhms, giving pretty consistent 100 mA charge rate.
Previously tested recharging solution : The button switch is an On/Off for the buzzer unit, to be kept in Off position while recharging as the TP4056 doesn't do load sharing. Small Lipo taped at the back.
IMPORTANT : Please take all necessary care while making if you are a beginner. Especially when working with Mains or any high power sources. Also when soldering, 3D printing, using tools. Please read up on safe practices. Take care with LiPo batteries - there are safety aspects regarding short circuit, over-charging and over-discharge. Protection circuitry on the batteries and in the charging system are required.
Arduino Code : Note - There is one issue which on rare occasions causes the buzzer to beep for a repeat press. Display remains unaffected though and continues to show correct values.
Base Station Code
Buzzer Unit Code
Circuit Diagrams :
Fusion360 Files : (Parametric editing currently not stable)
Base Station Enclosure
Buzzer Enclosure
STL Files :
Base Station Main
Base Station Cover
Buzzer Unit Main
Buzzer Unit Cover
Buzzer Unit Lock
Cura Profile Files : (Cura print settings for PLA, 0.4 mm nozzle)
Note: Place a support blocker at the key slot's lower part (buzzer unit main being printed upside down) to prevent unnecessary support that'll spoil the clean inner surface of the buzzer unit. A fillet exists such that suppport is not essential there.
Base Station Main
Base Station Cover
Buzzer Unit Main
Buzzer Unit Cover
Buzzer Unit Lock
G-Code Files : These were printed on a Creality Ender 3 in PLA. CAUTION !!! Use at your own risk as it may not suit Your setup. Take care and observe the entire print on the first go.
Base Station Main
Base Station Cover
Buzzer Unit Main
Buzzer Unit Cover
Buzzer Unit Lock
