Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
I'm not familiar with this library, but the point about a matrix keyboard is that each row is energised one at a time (port outputs) and for each, all of the columns are scanned (port inputs) to see if a key has been pressed in that row (or vice-versa). Accordingly, the key representation must...
Re: 20x4 lcd gets dim when on
I'm assuming that your 20x4 LCD is a module complete with driver electronics and just a 4 or 8 bit data interface, rather than the pure LCD glass unit with all segments and backplane brought out? If you are trying to drive a pure glass unit, be aware that LCDs...
Re: 20x4 lcd gets dim when on
Alternatively, the LCD module may have a CONTRAST pin. This actually varies the drive bias to the segments and has the effect of also changing the viewing angle. The connection usually takes the form of a pot between the supply and ground - the datasheet for the...
Interesting - and complex! All of the above design comments are usefully correct and should be followed.
For TTL, as noted, up to 10 inputs can be tied high together through a single 10K resistor for a 'one'. (Not using a resistor will work but isn't good practice.)
Any input can be...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
