ESPRI

ESPRI (ESP Radio Interface) project providing extended functionalities to ham radios.

The main goal of this project is to extend functionalities of ham radios with addition of a small PCB board that contains ESP32 microcontroller.

As such following features would be enabled:

• custom digital modes (modulated and demodulated by the ESP chip)
  • more advanced messaging
    • could be served as webpage by the esp chip itself
    • or have a mobile client as Meshtastic
• wireless UART connection to the radio
• broadcast .wav files
• turning any radio into IoT device via JSON API served from the ESP
• time domain scrambling (based on the HEKTOR 128 project)

The physicial inteface layer between the ESPRI and the host radio will be through the Kenwood connector.

The audio input and output (for the means of time domain scrambling) would be through the Kenwood connector.

Web panel

Here is a screenshot of a web control panel being served from the ESP:

Morse code beacon config:

Notifications (real-time communication via Websocket):

System info:

ESP Log:

I (8732) WEB/API/EVENT_HANDLER: Event id:3 received
I (8732) WEB/API/EVENT_HANDLER: Sent: SMS: API event: 3 received.

Dependencies

Hardware:

• ESP32

Some of the recommended boards:

ESP32 Lolin Lite (recommended, confirmed to work, lipo charger built-in):

Analog components

In order to interface radios through Kenwood connector following analog components have to be added to the ESP board:

Reference https://github.com/ludwich66/Quansheng_UV-K5_Wiki/wiki/Programming-Cable for Kenwood pinout.

Custom PCB:

This firmware uses:

• Espressif IoT Development Framework (ESP-IDF) v5.2.1

Getting started

Tip

You can flash this firmware with esptool.py or with ESP-Launchpad (using web browser)

To flash with esptool.py:

esptool.py write_flash 0x0 espri.bin

Once flashed:

• Connect to WIFI access point NOKIA-3K9N4H1 with password mypassword
• Go to http://192.168.4.1

Manual

Please take a look at the Wiki section for instructions, tips and more.

Development

With Visual Studio Code and ESP-IDF extension (recommended)

This method will install ESP-IDF toolchain locally with the help of the ESP-IDF Visual Studio Code extension.

PROS:

• IntelliSense in Visual Studio Code will work and errors are linted live during development
• Flashing, building, monitoring can be done directly from the Visual Studio Code

CONS:

• It will install toolchain locally

STEPS:

1. Install Visual Studio Code.
2. Install ESP-IDF Visual Studio extension.
3. Perform EXPRESS configuration and select correct ESP-IDF version

With Docker

This method will perform build within the Docker container.

PROS:

• Clean install.

CONS:

• IntelliSense in Visual Studio Code will not work (due to weird ESP-IDF structure and dynamic file inclusion)

STEPS:

1. Download ESP-IDF library:

git clone --recursive https://github.com/espressif/esp-idf.git

2. Remove examples folder:

rm -rf esp-idf/examples

3. Remove .git folder:

rm -rf esp-idf/.git

4. Update VS Code include PATH (file c_cpp_properties.json):

 "includePath": [
                "${workspaceFolder}/**",
                "${workspaceFolder}/esp-idf/components/**"
            ],

5. Install esptool:

pip3 install --user esptool

6. Build:

make docker

7. Flash:

make flash

How to contribute

Thank you for your interest in contributing to this project! Here are some of the many ways in which you can help:

• Report bugs
• Suggest improvements
• Audit the source code
• Submit PRs to fix bugs or implement features
• Test new releases and updates
• Record videos and post on other platforms
• Spread the word about this project
• Write and edit the documentation

References

• https://github.com/skuep/AIOC
• http://jtxp.org/tech/hektor_en.htm
• https://en.wikipedia.org/wiki/Delta-sigma_modulation
• https://en.wikipedia.org/wiki/Pulse-density_modulation
• https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/sdm.html
• https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/peripherals/i2s.html
• https://docs.espressif.com/projects/esp-idf/en/stable/esp32h2/api-reference/peripherals/ana_cmpr.html
• https://www.oldradioworld.com/shows/Vintage_Commercials.php (old radio show recordings, show copyrights are believed to be expired)

License

Copyright 2024 kamilsss655 https://github.com/kamilsss655

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.