09. Displays

Generally speaking electronic displays are made up of many LEDs, basically each pixel on the screen corresponds to a LED. Liquid crystal displays (LCD) are widely used as electronic displays, where their pixels can be controlled by computation, although they have a different technology they can be considered as low resolution screens that we have on our desktops.

We are going to drive the LCD display with an ATtiny15 microcontroller and say "hello world" on the LCD.

Another cheap technology for electronic display is the basic television. It is possible to drive a TV with video signals by a microcontroller. The image on television is made up of horizontal lines, and these can be controlled by pulses from a microcontroller. Between 0 and +5V pulses, 0 corresponds to white, +5V is black, and the middle is grey.

Controlling the horizontal lines with pulses from a microcontroller and saying "hello" .

Schematic (hello8.sch)
PCB (hello8.brd)
Serial output (Hello8.asm)
Bit timing test (hello8.osc.asm)
Display hello world (hello8.video.asm)
RS170 Pulse diagram for NTSC

schematic (hello7.sch)
PCB (hello7.brd)
serial output (hello7.asm)
display hello world (hello7.lcd.asm)
LCD module specification
HD44780.pdf (Dot matrix Liquid Crystal Display Controller/Driver)

Electronic-ink is a promising display technology, where particles move inresponse to an externally applied electric field. But it is sad that there are only applications for cellphones, tablet liek PCs etc.