I started this project with the idea of designing a stand-alone 5 moments tape reader to see what the TTY tapes I have contain.
It can also be used to transfer them to my computer using the USB port.
It is designed around:
- an old Sagem mechnical tape read unit,
- an Arduino Nano card,
- a 15V DC power supply,
- a 5V buck-down converter connected to the arduino card,
- a 24V buck-up converter needed to power the mechanical reader.
A BUK582 PowerMos Logic Level FET is used to drive the mechanical reader.
The reader's coil flyback device is made of a general purpose diode connected together with 12V Zener diode.
This keeps the voltage level to the high level required for a fast return to the of electro-magnet un-energized state.
This reader can be setup to select:
- the input tape format: ITA2, FIALKA (Czechoslovakian, Russian),
- the output format: binary (ALL), ASCII (ITA2) or UTF-8 (FIALKA),
- the read speed: 'fast' or 'slow' step advance.
Next version will add: US Telex, FIALKA (Hungary, DDR).
A push button allows for step-by-step advance.
The LCD display shows:
- the current binary data together with the ASCII decoded character,
- the twelve last decoded characters.
The related code has been written to make full use of the input interrupt on change and 16bits counter arduino features.
It is small enough to be run on a Nano168 core. It also works - with small modifications - on a Mega2560 core which drives a dual readers unit.