LCD Display

[TimD]

I have a project that I would like to add a LCD display too.

It is an auto antenna selector that use data from radio to select which transistor to short to ground to activate a relay.It has 9 2n4401 trans for this.

It is set up to use 2 different types of radios.What I would like to know is if there is a way to send signal to LCD display that can use radio 1 as on line 1 of display which antenna is in use,,and line 2 of lcd to use information for 2nd radio.

Radio 1 uses the 4028b decoder for its circuit
Radio 2 uses 4 Lm339 comparators for its circuit.
Both band decoders are on there separate pcb and the only thing they share in common is the 9 2n4401 going out to the relay control box.

What I would like to do if it can be done is let 1 radio use Line 1 of LCD other radio Line 2.Right now when I switch radios I have to pull the unit out and unplug 1 and then plug the other one up in its socket.If I have to add a second LCD i guess that what I will do,,but trying all other sources before I do that.

Tim

 

[Wp100]

Hi,

To use a lcd you need an small microprocessor to send the messages to it - see Nigel tutorials for an idea of whats needed.

 

[TimD]

Yes I am using either the pic16f628 or the 16f877a and using the 2x20 hd44780 lcd display.I am new to electronics and mcu's.I also have a 74LS151N mux to go to the inputs of the mcu.Is there a way to do what I am wanting on a single lcd display or will I need 2.

 

[Gobbledok]

Yes you can do that on one LCD.

The LCD controller has internal memory addressed from 0 - 80. For line one you write to addresses 0 - 20. For line two write to addresses 40 - 60.