Pages: [1]   Go Down
Author Topic: is there another way to connect to a 4 line lcd? to reduce connections  (Read 722 times)
0 Members and 1 Guest are viewing this topic.
uk
Offline Offline
Sr. Member
****
Karma: 0
Posts: 314
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

hi,

im using a 4 line lcd for a project using the usual configuration / connection 6 pins.

im just wondering if there is another way to connect to the lcd  to reduce the amount of pins, as i need more pins.
« Last Edit: December 18, 2012, 04:50:29 am by jonisonvespa » Logged

Málaga, Spain
Offline Offline
Edison Member
*
Karma: 40
Posts: 2182
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Shift registers (1,2 and 3 wire config), I2C and SPI. They all need additional electronics.
Logged

   

Pakistan
Offline Offline
Sr. Member
****
Karma: 6
Posts: 357
Arduino rocks
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I am using 3-wire successfully. You have to make a custom PCB in your home. PCB circuit given here:
http://code.google.com/p/arduinoshiftreglcd/
You can use latest LCD library included in Arduino 1.0.1 from great 'fm' smiley-mr-green furthermore, add a good menu in your project and use
http://arduino.cc/forum/index.php/topic,99693.0.html
this will save some more pins...
« Last Edit: December 18, 2012, 09:10:21 am by Khalid » Logged


uk
Offline Offline
Sr. Member
****
Karma: 0
Posts: 314
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

thanks i found this one  looks ideal and frees up 4 pins

thank you


* lcd.png (21.51 KB, 816x415 - viewed 32 times.)
Logged

Pakistan
Offline Offline
Sr. Member
****
Karma: 6
Posts: 357
Arduino rocks
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

However, i am using 74HC595 Shift register.... smiley-mr-green
Logged


Offline Offline
Edison Member
*
Karma: 116
Posts: 2205
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

1) Use a serial interface: uart, spi, i2c, etc.
2) Use a shift register: hc164 or hc595. I typically use a 3-wire interface.
3) Use rc networks to further reduce the number of lines: I think wrote a test piece a while ago reducing it down 1 line. But 2 lines are fairly doable, with no appreciable degradation in speed / performance.
Logged

Norfolk UK
Offline Offline
Edison Member
*
Karma: 66
Posts: 2481
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Fit a serial backpack like this one http://www.hobbytronics.co.uk/i2clcd-backpack-v2 and you can reduce the I/O pin count to 1 if you use it as serial RX pin.
Logged

There is no such thing as a stupid question but there are a lot of inquisitive idiots.

uk
Offline Offline
Sr. Member
****
Karma: 0
Posts: 314
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

thanks for the help, due to cost i intend using a 74HC595 Shift register

just wondering about the lcd library will it work using the standard library?

thanks
Logged

United Kingdom
Offline Offline
Tesla Member
***
Karma: 224
Posts: 6593
Hofstadter's Law: It always takes longer than you expect, even when you take into account Hofstadter's Law.
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Or use a 128x64 graphic lcd that uses the ST7920 controller instead of a character lcd, then you need only 2 pins to control it, and you get nicer text too.
Logged

Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

Pakistan
Offline Offline
Sr. Member
****
Karma: 6
Posts: 357
Arduino rocks
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

thanks for the help, due to cost i intend using a 74HC595 Shift register

just wondering about the lcd library will it work using the standard library?

thanks
yes
Logged


Pages: [1]   Go Up
Jump to: