Bluetooth Wall Audio Player

A low power, wall mounted, Bluetooth audio player, clock, and environmental monitor

Warning

This is personal project. It was built and works without issue for my purposes. It is made public here in case some part of it is useful to others, but neither the hardware nor firmware have been rigorously tested.

Features:

• Media/volume controls
• Song metadata display
• Time, temperature, pressure, humidity display on idle
• Ultra low power sleep with proximity sensing wakeup
• Differential analog and S/PDIF digital audio output

This repo contains the firmware and PCB/enclosure design.

See custom electronics projects at duk.io for full project details.

Build

The project uses the PlatformIO dependency management/build system. If you have PlatformIO installed, executing the run command in the root folder should 🙏 be all that is required for a successful build. The platformio.ini file contains the required configuration and PlatformIO will download the required platform dependencies and toolchain.

1. Clone repo and download submodules

> git clone https://github.com/canardos/bluetooth-wall-player.git
> cd bluetooth-wall-player
> git submodule update --init

2. Build firmware (PlatformIO must be installed)

> pio run

3. Upload to device

Similarly, use pio run --target upload to upload the firmware to the device. You'll likely need to update the upload settings in platformio.ini to reflect your settings, or use your own upload tool.

> pio run --target upload

4. [optional] Create project files for IDE

If you want to view/edit the project in your favorite IDE, use PlatformIO to generate the appropriate setup/workspace files and import the project:

> pio project init --ide [atom|clion|codeblocks|eclipse|emacs|netbeans|qtcreator|sublimetext|vim|visualstudio|vscode]

See the PlatformIO documentation for further details.

Using an alternate build system

Platform dependencies

If you wish to use a different build system, you will need:

ST STM32 CMSIS headers	Peripheral/register definitions
CMSIS headers/source	CMSIS HAL functionality - SysTick_Config, NVIC_xxx etc.
CMSIS Cortex-M3 system source	SystemInit()/SystemCoreClockUpdate() implementation and SystemCoreClock
Startup source file	ASM file containing the startup code and vector table
Linker script	Tells the linker how to setup everything in flash/SRAM

All of these are available in the STM32 SDK available from ST Micro.

Compiling / linking

platformio.ini lists the required compiler flags. Be sure to use --specs=nano.specs and --specs=nosys.specs when linking using your own tools.

Compiler

The project was built with gcc-arm-none-eabi 9.2.1 It should work with any later GCC version and possibly with other compilers. The code contains some GCC flags and some C99 VLAs.

Target requirements

MCU	STM32F1xx
Flash	>42kb
SRAM	>8kb

Dependencies (firmware)

CMSIS

PlatformIO should automatically include/link the correct headers/sources from the STM32 SDK. Version 9.0.0 was used in production.

Libpekin

Libpekin is a collection of shared MCU-related code resulting from this and other projects. It's included as a Git submodule in the lib folder. PlatformIO will include the lib subfolders automatically.

Hardware

PCB

The PCB was designed with KiCad v.5, but the files have been upgraded to v.7 and are located in /hardware/pcb. Gerber output for the first revision is located in /hardware/pcb/plots_rev_a.

Important

Several fixes have been made to the design, which are implemented in the latest schematic/pcb files, but are not present in the revision A plot output.

See the KiCad documentation for information on installing and using KiCad.

Custom symbols and footprints required by the board are included as a Git submodule at /hardware/pcb/kicad-mycustom-lib, and are included in the KiCad project as a project-specific library.

Enclosure

The enclosure design includes a laser-cut wooden facade. The CAD files for the design are located in /hardware/enclosure/laser_cut_facade.

A Sketchup model I used to model the mechanical constraints of the design is included in /hardware/enclosure.

Folder structure

BTWallPlayer
|
+--artwork           | SVG sources for animation
|  |
|  +--render         | bitmap output frames
|
+--hardware
|  |
|  +--pcb           | KiCad schematic and board design files
|  +--enclosure     | Enclosure Sketchup model and laser cutting
|                   | design files
|
+--lib
|  |
|  +--libpekin       | Libpekin platform independent code
|  +--libpekin_stm32 | Libpekin STM32 specific code
|
+--src
|  |
|  +--data           | Image and font data
|  +--devices        | Hardware device drivers
|
|--test              | No tests in use

License

This software is available under the MIT license.