Continue to Site

Welcome to EDAboard.com

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.

Register Log in

character lcd input protection

Status
Not open for further replies.
S

seyyah

Advanced Member level 2
Joined
Oct 7, 2001
Messages
646
Helped
8
Reputation
16
Reaction score
8
Trophy points
1,298
Activity points
6,233
Some times a character based lcd (hd44780) can pickup noise or lost synchronization with the controller.

1- What do you suggest to protect inputs to prevent from getting unwanted noise (commands, data).

2- If it gets noise and display is garbaged, what can i do to correct it in the controller.

I would like to hear you suggestions, thanks.
 

I know, that this happens with an unsuitable interface design. e.g. connecting the LCD through a flat cable. If you intend to comply with EMC standards for electrostatic discharge and burst voltage, you have add some kind of supervision to make the device automatically recover from a fault condition.

Periodically resetting the controller would be a kind of brute force method, but basically works. A more intelligent way is e.g. to read back the controller mode and display content and perform a reset in case of a deviation.
 

FvM said:
I know, that this happens with an unsuitable interface design. e.g. connecting the LCD through a flat cable. If you intend to comply with EMC standards for electrostatic discharge and burst voltage, you have add some kind of supervision to make the device automatically recover from a fault condition.

Periodically resetting the controller would be a kind of brute force method, but basically works. A more intelligent way is e.g. to read back the controller mode and display content and perform a reset in case of a deviation.
Click to expand...

OK i tried resetting, but sometimes it does not correct itself actually resetting sometimes makes the problem itseft. Also clear display command does not clear the screen. I am using the resetting sequence all the time. May be two writing collide, i will try to inhibit all lcd writings during a reset but i could not understand why display clear command does not work.
 

Ive the same problem with my lcd. is there any hardware input protection? coz i use a parrarel lcd which have to use flat cable as a connection interface.

i think read back the lcd is not the solution, the problem keeps accur sometimes.

i tried to tied the metal case to ground/earth terminal. but it doesnt fix the problem.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top