Bit banging through a USB parallel port adapter

hackaday.com 21 Feb '13, 8pm

Bit banging through a USB parallel port adapter

Sure, adding a microcontroller would make this dead simple. All you need to do is program the chip to emulate the printer’s end of the communications scheme. But that’s not the approach taken here. Instead the USB to RS232 (serial) converter also pictured above is used as a reset signal. The strobe pin on the parallel port drives an inverter which triggers a thyristor connected to the busy pin. Thyristors are bistable switches so this solution alone will never clear the busy pin. That’s where the serial connection comes into play. By alternating the data transmitted from the computer between the bit-bang values sent to LP0 and 0xF0 sent to the serial connector the eight parallel data bits become fully addressable. See the project in action in the clip after the break.

Full article: http://hackaday.com/2013/02/21/bit-banging-through-a-usb-...

Tweets

@Octoate » 21 Feb '13, 9pm
Ich dachte, da hätte man immer Probleme mit dem Timing!? - Bit banging through a USB parallel port adapter - [link]
@tsairox » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter: If you’ve ever looked into low-level parallel port... [link] #tech #tfb
@knightowlcasts » 21 Feb '13, 8pm
Hack a day Bit banging through a USB parallel port adapter: If you’ve ever looked into low-level parallel port... [link]
@TechKnowledgeIt » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter [link] #tki
@IoTFeed » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter: If you’ve ever looked into low-level parallel port acce... [link] #iot
@fcassia » 21 Feb '13, 8pm
RT @hackaday: New post: Bit banging through a USB parallel port adapter [link]
@GeekHugger » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter [link] via @hackaday
@MossadBlackWolf » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter: If you’ve ever looked into low-level parallel port access yo... [link]
@robofun » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter [link]
@SuprayCyber4rt » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter [link]
@imcyberteam » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter [link]
@ProdukHerbalID » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter: If you’ve ever looked into low-level parallel port access yo... [link]
@TVone_Online » 21 Feb '13, 8pm
Bit banging through a USB parallel port adapter: If you’ve ever looked into low-level parallel port access yo... [link]