Back to School with STEM-Limited-Time Event(Aug 6-Sep 5)

user-img

Marco Serwis

  • 1 Projects
  • 2 Followers
  • Sep 02,2025
+ Follow

H2S-based walkie talkies

This LoRa walkie-talkie works by digitizing and compressing voice, sending it over LoRa in small data packets, and playing it on the receiver.

H2S-based walkie talkies
 
  • thumbnail-img
 

Tools, APP Software Used etc.

  • Arduino IDE

    Arduino IDE

    Arduino

Story

 

Using a LoRa module to build a walkie-talkie is an innovative project, but it’s quite different from traditional analog or digital voice walkie-talkies. LoRa (Long Range) is a low-power, long-range wireless communication technology designed for low data rate applications, like sensor data in IoT—not for continuous audio streaming. However, it can still be used for walkie-talkie-style communication with some trade-offs.

 

This LoRa walkie-talkie works by digitizing and compressing voice, sending it over LoRa in small data packets, and playing it on the receiver. It’s not real-time or full-duplex, but provides very long range, low power, and basic walkie-talkie functionality for voice messages.

 

 


 

1. Hardware Components

 

  • H2S – Dev board

  • Microphone (electret or MEMS) for audio input

  • Speaker or earphone for audio output

  • Audio codec (e.g., VS1053 or custom ADC/DAC) for compressing/decompressing audio

  • Push-to-Talk (PTT) button

  • Power supply (battery)




 

2. High-Level Working Process

 

a. Capture Audio

  • The microphone captures analog audio signals when the user presses the PTT button.

  • Audio is digitized using an ADC (Analog to Digital Converter) on the microcontroller or an external codec.

b. Compress & Packetize Audio

  • Raw audio is compressed (e.g., using ADPCM or other lightweight codecs) because LoRa has limited bandwidth (~300bps to 37.5kbps depending on settings).

  • The digitized audio is broken into small packets suitable for LoRa transmission.

c. Transmit Audio Over LoRa

  • The packets are sent sequentially over the LoRa radio.

  • Due to LoRa’s long range but low data rate, this is typically half-duplex and delayed (latency from buffering and packet transmission).

d. Receive and Reconstruct Audio

  • The receiving device listens for incoming packets.

  • It reassembles and decompresses the audio.

  • Finally, it outputs the audio through a DAC and speaker.


3. Key Considerations & Challenges

Aspect

Details

Latency

LoRa is not real-time; expect a delay of ~100ms to several seconds depending on bitrate and compression.

Audio Quality

Low bitrate audio (e.g., 8 kHz, 4-bit ADPCM) results in lower quality, but intelligible voice.

Duplexing

Only half-duplex possible (talk OR listen, not both at once), similar to traditional walkie-talkies.

Power Consumption

LoRa is very low-power for data transmission, but audio processing (especially codecs) can consume more.

Range

Can reach 1-15+ km depending on environment, antenna, and power settings. Far exceeds typical walkie-talkies.

 

Topic
View All

H2S-based walkie talkies

This LoRa walkie-talkie works by digitizing and compressing voice, sending it over LoRa in small data packets, and playing it on the receiver.

26
 
1
0
0

Share your project on social media to expand its influence! Get more people to support it.

  • Comments( 0 )
  • Like( 1 )
/1000
Upload a photo:
You can only upload 1 files in total. Each file cannot exceed 2MB. Supports JPG, JPEG, GIF, PNG, BMP

You May Also Like

View All
Add to cart
Board Type : GerberFile :
Layer : Dimensions :
PCB Qty :
Different PCB Design
PCB Thickness : PCB Color :
Surface Finish : Castellated Hole :
Copper Weight : 1 oz Production Time :
Total: US $
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.

PCB Assembly

PCBA Qty: BomFile:
NO. OF UNIQUE PARTS: NO. of Components:
Country: Shipping Way:
Assembly Cost: US $
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
3dPrintingFile : Size :
Unit : Volumn :
3D Printing Qty : Material :
Total: US $12.99
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
Acrylic Type : AcrylicFile :
Dimensions: Engrave:
Acrylic Qty :
Acrylic Thickness:
Acrylic Color:
Total: US $12.99
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
CNC Milling File : Size:
Unit: Volumn:
CNC Milling Qty : Material:
Type of Aluminum: Surface Finish:
Tolerance:
Surface Roughness:
Total: US $12.99
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
Item Price Qty Subtotal Delete
Total: US $0.00
Certified Product | Supported Purchase: Full After-sales Protection