SIDPod

The SIDPod is a PSID player for RP2040 microcontroller based boards, such as the Raspberry Pi Pico or the Solder Party RP2040 Stamp. Playback is based on the SID emulator found in Teensy-reSID, which in turn is based on reSID

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• Building
  • Software
    • Building from source
    • Prebuilt binaries
  • Hardware
    • Construction
    • Power
    • Bill of materials
• Using
  • Finding music
  • Creating playlists
  • Adding music
  • Playback
    • Chip support
    • Playlist selection
    • Song selection
  • Visualization mode
  • Volume control
  • Pocket mode
  • Deep sleep
• Beta disclaimer
  • General disclaimer
• What's on the horizon?

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Building

Software

Building from source

SIDPod requires both the Raspberry Pi Pico SDK and the pico-extras. Make sure to grab these and either put them next to the SIDPod directory or, if you have them somewhere else, point the PICO_SDK_PATH and PICO_EXTRAS_PATH environment variables to their respective location. You'll also need CMake on your path. If/when these prerequisites have been satisfied, you're almost ready to run the cmake command to create the build directory and configure the build. One last thing to do is to make sure the board type matches the one you have. By default, SIDPod builds for the Solder Party RP2040 Stamp, which, for example, has a larger NAND flash than the more common Raspberry Pi Pico. Using a RP2040 Stamp UF2 on a Pi Pico would most likely cause issues on the first run, as the flash will get formatted, using board specific settings, if no readable FAT filesystem is found on it. Changing board type can either be done by modifying the PICO_BOARD variable in CMakeLists.txt or by setting the PICO_BOARD environment variable before running the cmake commands. The correct value for the Raspberry Pi Pico is 'pico'. Once this is done, the build is configured by running:

cmake -B cmake-build-debug

Alternatively, if you have Ninja installed, you can save a few seconds of your valuable time by instead running:

cmake -G Ninja -B cmake-build-debug

Then, to build the SIDPod.uf2 binary, issue:

cmake --build cmake-build-debug --target all

Once the build finishes, just follow the official instructions for loading a UF2 binary onto the board. For Raspberry Pi Pico you hold down the BOOTSEL button when you plug it in and then copy SIDPod.uf2 to it, once it appears as a drive named RPI-RP2. For some other types of boards, such as the Solder Party RP2040 Stamp, this mode is activated by double-clicking the reset button.

Also note that if you're running macOS, copying using Finder might fail with this error: The operation can’t be completed because an unexpected error occurred (error code 100093). If this is the case, fire up the 'ol terminal and do:

cp cmake-build-debug/SIDPod.uf2 /Volumes/RPI-RP2

Prebuilt binaries

To get a jump start you can also grab the prebuilt binaries. There are two versions, one for the Solder Party RP2040 Stamp and one for the Raspberry Pi Pico.

Hardware

Construction

Since the main goal is to make a portable player, the actual build and design is up to you, the maker. My current prototype is built inside a 3-AA battery box I had lying around, using a Solder Party RP2040 Stamp and a 3.7V 150mAh LiPo battery. However, the breadboard design I'm using for development, based on a Raspberry Pi Pico H, looks like this:

The breadboard schematics.

In reality, the development breadboard looks a bit different. I use a dual lane breadboard and connect to the SIDPod Pico board via a Picoprobe, for debugging and a less painful development process.

The development breadboard setup.

The working prototype. Please excuse the soldering. I'm a lover, not a solderer. 😜

Power

The main advantage of the Solder Party RP2040 Stamp, besides its size, is the onboard LiPo charger. This removes some complexity and saves space when moving beyond the breadboard design. Many RP2040 projects can easily run off the power provided from the host computer over the built-in USB port. The SIDPod however, will enter a special USB device state and start to mimic a USB mass storage device once connected to a computer. More on that here. This poses a problem, if you actually want to use it for what it's designed for - to play PSIDs. That problem can easily be solved by powering it from any power source connected to the VSYS pin. That power source can be anything from a 3.7V LiPo battery to a separate USB breakout bord, with the breakout boards VBUS connected to VSYS on the Pico Board and the breakout board GND connector connected to any GND on the Pico Board. In my development breadboard setup I power the SIDPod Pico Board from the Picoprobe Pico Board. In the next section I've listed the components needed for a few different options:

Bill of materials

Option 1 - Using a Solder Party RP2040 Stamp (the prototype setup):

• 1 x Solder Party RP2040 Stamp
• 1 x Adafruit I2S 3W Class D Amp - MAX98357A
• 1 x LCD OLED 0.91″ 128x32px I2C
• 1 x 3.5mm stereo jack
• 1 x Rotary encoder w switch
• 2 x 100Ω resistor
• 1 x Battery LiPo 3.7V 150mAh

Option 2 - Using a Raspberry Pi Pico (the breadboard setup):

• 1 x Adafruit I2S 3W Class D Amp - MAX98357A
• 1 x LCD OLED 0.91″ 128x32px I2C
• 1 x 3.5mm stereo jack
• 1 x Rotary encoder w switch
• 2 x 100Ω resistor

Option 2a - Add a Raspberry Pi Pico with Picoprobe, for debugging, binary upload and power through VSYS:

• 2 x Raspberry Pi Pico H

Option 2b - Power the Raspberry Pi Pico through a USB breakout board:

• 1 x Raspberry Pi Pico H
• 1 x Breakout board USB-C

Using

To keep the construction as simple as possible I tried to minimize the number of physical controls, and a rotary encoder with a built-in push button provides enough versatility to cater to every possible use case of this rather minimal design. Therefore, controls are both contextual and pattern driven.

Finding music

The SID or Sound Interface Device, which this player does a rudimentary emulation of, was a component in the world's most popular home computer, the Commodore 64. Due to its legendary status and, to this day, very active community, there's no shortage of SID files to fill your SIDPod with. The most complete collection is the High Voltage SID Collection. It has everything, from cult classics by the legendary Jeroen Tel to contemporary pieces by Kamil Wolnikowski, aka Jammer. Download the full archive and use one of the SID players referenced on that page to find the music you like. The collection contains both PSIDs and RSIDs. Most PSIDs are playable and with the introduction of reSID, (version 2.0beta and later) some RSIDs are playable. However, full compatibility is not guaranteed yet. This is being worked on though.

Creating playlists

With the introduction of version 2.0beta, music must be put in playlists. And the definition of a playlist is a folder with at least one PSID in it. Furthermore, to avoid out of memory errors, the maximum number of PSIDs in a playlist is restricted to 256. And the number of playlists is limited to 256 as well. This means that the maximum number of PSIDs is 65536. Coincidentally, the memory size of our favorite 8-bit home computer. ❤️

As you may have figured out, this many PSIDs would never fit on the internal flash. They will however fit on a standard size SD card, which is something that will be supported when SIDPod 2.0 is out of beta.

Adding music

The SIDPod doubles as a USB mass storage device, which means that if you plug it in to your computer it will show up as a regular, FAT-formatted drive. This means that adding and removing PSIDs is as easy as copying or deleting files. There are a few caveats though:

• Since version 2.0beta PSIDs must be put in folders. As mentioned above.
• Use it with moderation. [Fat