https://github.com/themozg/avr-pc-beeper
PC speaker which plays Imperial March on boot
https://github.com/themozg/avr-pc-beeper
avr imperial-march morrowind pci star-wars
Last synced: 11 months ago
JSON representation
PC speaker which plays Imperial March on boot
- Host: GitHub
- URL: https://github.com/themozg/avr-pc-beeper
- Owner: TheMozg
- License: mit
- Created: 2018-02-17T16:24:42.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2018-06-07T21:55:10.000Z (about 8 years ago)
- Last Synced: 2025-04-06T09:06:49.238Z (about 1 year ago)
- Topics: avr, imperial-march, morrowind, pci, star-wars
- Language: C
- Homepage:
- Size: 2.99 MB
- Stars: 13
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# AVR PC Beeper
Replace boring POST beep with Imperial March or Morrowind theme!
## Features
* 2 boards with integrated speaker, which play selected tune on boot
* 4 modes (controlled by 2 switches):
* (0b00) - passthrough, POST beep is played as-is
* (0b01) - Star Wars Imperial March
* (0b10) - Morrowind theme (aka Nerevar Rising / Call of Magic)
* (0b11) - Russian anthem
* Adjustable volume (blue potentiometer)
## Hardware
To detect POST signal AVR microcontroller reads motherboard speaker ground pin `-SP`.
I've created 2 devices in different form factors.
Both are based on `ATtiny85` microcontroller
(simply because I had these lying around, you may use a different one).
Schematic for both boards is mostly the same
(mini-ITX board doesn't have `SW3` switch):
### PCI board
Large board which plugs directly into PCI port.
Has an external panel, which exposes 2 toggle switches (`SW1` and `SW2`) and a potentiometer shaft (`P1`).
Note that when installed, back panel may be flipped. To select passthrough/tune
correctly, orient the panel so that volume shaft is the left side.
This board also has a dedicated dip switch (`SW3`) which disables POST trigger.
When this dip switch is ON, avr doesn't read motherboard speaker pin (`-SP`).
Instead, it plays selected tune once after being powered.
This means the tune may be played after waking from sleep mode.
This dip switch is ignored when passthrough is selected.
### Mini-ITX board
Tiny board, suitable for mini-ITX builds where space is at premium.
Tune/passthrough is selected with 2 on-board dip switches (`SW1` and `SW2`).
Unlike PCI build, there is no dip switch to disable POST trigger (`SW3`).
The board must be manually connected to a 5v power source with wires.
Pin order (top-down, board is positioned so that pins are on the left side):
1. `+5V` - power source, you can use speaker+ pin on the motherboard
2. `-SP` - trigger pin, connects to speaker- pin on the motherboard
3. `gnd` - you can use ground pin from any free port on the motherboard
Known issue: when volume is set above ~90%, the board may start playing satanic
screeches or otherwise behave strangely.
## Software
### How to build
Install required packages:
* `avr-gcc`
* `avr-libc`
* `avrdude`
Run `make` to build `.hex` file.
### How to flash
You can use any AVR ISP programmer supported by `avrdude`.
I am using Arduino as ISP,
to use other programmer modify `PROGR` variable in `Makefile`.
Connect the programmer and run `make flash PORT=` to upload `.hex` file to AVR.
You may need superuser privileges,
for example when using Windows Subsystem for Linux:
`sudo make flash PORT=/dev/ttyS3`
## Revisions
* rev. 2 (current)
* [rev. 1](https://github.com/TheMozg/avr-pc-beeper/tree/rev.1) - first 2 boards, see corresponding branch