hello there i came across a discusion in the general forum about led displays and i thought of a cool idea i have for one but it needs to be on a large scale! i got this schematic: instead of 8x4 i need roughly 30x30 is this even possible and if so anyone got a clue as to what chips i need to repalce the 74164 shift register and the 74138 decoder, or if there is another way prehaps using pics to mimic the function of the chips? thanks in advance
The 74164's are cascadable. However, I'd opt to divide the rows into sections of 10 and multiplex the 30x10 blocks individually, as the duty cycle will make quite an effect at 1/30.
cool thanks so what sort of chips would i need for 10x30 and what software would run it, any lcd/vfd or would i need to program a driver? thanks for your help
Well for something like this you'd have to create your own driver. A possible workaround would be to drive the display with a microcontroller, and enable commands similar to the HD44780 protocol to drive the microcontroller. That way you could still use any program on your PC to control the display.
it might be easier to get something like the MAX6955, a pre made display driver chip that can handle a 7x28, 8x14, ect up to 128 individual LEDs it also has 32 key scaning built in... pretty cool the whole thing hooks up to a serial port on your computer
