Very Basic HD44780 driver for Stellaris LaunchPad

[The_YongGrand 1]

Here's a very basic HD44780 driver for Stellaris Launchpad.

 

Supports up to 20x4 LCD and a full PORTB register is used. Due to the nature of the GPIOPinWrite function which uses masking and whatnots, extra code on the driver will be written in the future to accomodate such functions.

 

Uses two files: hd44780_lp.c and hd44780_lp.h

 

An example is in the attachment. It's called "lab2" because I fooled around with the Stellaris Launchpad Workbook earlier.

 

Note: Please refer to online tutorials on the HD44780 connections.

 

Comments are greatly appreciated!

 

lab2_revised.zip

[bluehash 1,581]

Thanks! Put up some pics

Moving this to "Code Vault"

[The_YongGrand 1]

Thanks! Put up some pics

Moving this to "Code Vault"

 

Thanks. Added a main pic. This one uses a 20x4 LCD and I added a few phrases to fill up the screen.

 

Edit: To those who have downloaded and tested the code just to find boring dark boxes on the screen, I made a careless mistake in the header file. I've fixed the header file again - please download again. Apologies for the inconvenience.

[remick1426459870 0]

I've just try to use your driver with my display.

 

Something went wrong.

I need a little bit help/hint.

 

That is what I can see on display:

 

 

 

I assume that display is OK since it is working well with arduino.

[The_YongGrand 1]

I've just try to use your driver with my display.

 

Something went wrong.

I need a little bit help/hint.

 

I assume that display is OK since it is working well with arduino.

 

Hello there,

 

Is it the latest "lab2" you have downloaded? Because the older one doesn't work.

 

Plus, are the connections to the Launchpad tight? Sometimes loose connections will cause the LCD not to start.

[remick1426459870 0]

Hi,

 

I've downloaded lab2_revised.zip from your first post.

 

Yeah - I'll make sure that connections are proper. That might be weak point.

I'll let you know if that will work.

 

Thanks for answer.

[remick1426459870 0]

Unfortunately still display doesn't work.

 

One additional question. Where do you connect RW pin of the LCD? Is it just floating?

 

Edit: I've just grab another 16x2 LCD and there is exactly the same effect. Maybe then it is some kind of settings in your Code Composer? Did you set something in your project what could be not set automatically after import?

[znanev1426459859 0]

One additional question. Where do you connect RW pin of the LCD? Is it just floating?

 

R/W pin should not be left floating. Tie it to ground (1 = Read, 0 = Write) - the library just writes commands to the LCD module

[remick1426459870 0]

R/W pin should not be left floating. Tie it to ground (1 = Read, 0 = Write) - the library just writes commands to the LCD module

 

Thanks a lot !

Problem solved

After grounding R/W pin display started to work.

 

 

Thanks guys !

[scompo 0]

Wow, this is really nice!

[dlejob 0]

Hi,

 

I have a hard time understand the pins assignment on the launch pad (first time user), Can you help?

 

For example:

 

 

#define RS GPIO_PIN_0 Is this conect to PD0 ????

#define E GPIO_PIN_1 Is this conect to PD1 ????

#define D4 GPIO_PIN_4 ??

#define D5 GPIO_PIN_5 ??

#define D6 GPIO_PIN_6 ??

#define D7 GPIO_PIN_7 ??

 

Thanks for your help.

[DanAndDusty 62]

Hi,

 

I have a hard time understand the pins assignment on the launch pad (first time user), Can you help?

 

For example:

 

 

#define RS GPIO_PIN_0 Is this conect to PD0 ????

#define E GPIO_PIN_1 Is this conect to PD1 ????

#define D4 GPIO_PIN_4 ??

#define D5 GPIO_PIN_5 ??

#define D6 GPIO_PIN_6 ??

#define D7 GPIO_PIN_7 ??

 

Thanks for your help.

 

I don't have one of these LCDs but at the top he says Full port B used.. So I would read those as GPIO_PIN_1 is PB1 and so on..

[dlejob 0]

Thank you. I tried and it works!!

[gtivey 0]

Hi All ---

 

Managed to get the LCD driver working -- Thanks for the module !

 

> In the LCD module, can you just print one or two characters, then move the cursor to a new location and put another character?

 

I am considering using this driver to display temperatures.

 

Have made more progress in 4 days with Stellaris than a couple of months with STM32.

 

Thanks to all those who worked hard integrating Stellaris with Linux and Eclipse.

 

--Gary

[dlejob 0]

I made some modifications to the drivers.  They can be found here

 

https://docs.google.com/folder/d/0B2e01HJNFmp0ZFJHN3k1ZUQ2UHM/edit

 

See the example in the main.c