Difference between revisions of "Turntable USB interface"
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=Operation= | =Operation= | ||
| + | *Indicator light is off | ||
*Plug in USB stick or iPod | *Plug in USB stick or iPod | ||
| − | * | + | *Indicator light is green to indicate all is well - iPod or memory stick is detected |
*Place stylus on a chosen track | *Place stylus on a chosen track | ||
| − | * | + | *Press button |
| − | *Sound file is written onto the device | + | *Indicator light is red for record |
| − | * | + | *You will also see the activity light on the USB device light |
| + | *Sound file is written onto the device in WAV/AIFF format | ||
| + | *Press button | ||
| + | *Indicator light is green | ||
| + | *You can press the button to begin recording again to a new file | ||
| + | *Unplug device (only when light is green - your risk if you unplug on red) | ||
| + | *Indicator light goes out | ||
| + | |||
=Systems= | =Systems= | ||
*Power supply | *Power supply | ||
Revision as of 09:17, 10 February 2007
I would like to retro-fit my 1970's pioneer turntable to be able to record onto a iPod or other USB device.
Contents
Why?
Because I like to combine technology in unusual ways. And also to bring together analog and digital without a computer getting in the way.
There is a computer involved, but not a PC.
Operation
- Indicator light is off
- Plug in USB stick or iPod
- Indicator light is green to indicate all is well - iPod or memory stick is detected
- Place stylus on a chosen track
- Press button
- Indicator light is red for record
- You will also see the activity light on the USB device light
- Sound file is written onto the device in WAV/AIFF format
- Press button
- Indicator light is green
- You can press the button to begin recording again to a new file
- Unplug device (only when light is green - your risk if you unplug on red)
- Indicator light goes out
Systems
- Power supply
- plug pack 12V 100mA
- Split from it's case and wired in parallel on the AC side of the turntable's main transformer
- Analogue phono stage (requires ±12V DC)
- to be build on veroboard
- ICSP programmer required to completely rewrite the bootloader - AVRISP mkII
Microcontroller
Blackfin- Arduino NG AVR microprocessor board
- Schematics
Features
- ATmega168 AVR processor
- Digital <-> Analogue converter
- C library and compiler supplied as open source
- AVR emulator
- AVR libC
Board
- 78MO5 voltage regulator
- FT232R USB to serial driver
- S16B0016 clock
- USB D-type connector
Operating system
- Implementing USB 1.1 in AVR assember
- gcc, libc supplied and open source
- No real operating system required
- svn tree
- bootloader supplied and open source
- libipod [tar] program to modify iPod's XML playlist file to add the newly created track to the playlist
- ContikiOS
Main loop
- boot up
- USB device?
- loop
- yes-mount fs and open file descriptor
- no-loop
- set led to Red
- loop
- check A to D for signal input
- check threshhold
- begin recording
- or
- loop
- begin recording
References
- Lots of GNU tools for AVR
- AVR diagrams (good)
- Custom power supply project
- Good links and downloads for emulators, libc...
