lcd4linux-devel

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Luis.F.Correia <Lui...@se...>]

Hi! 

> -----Original Message-----
> From: Stefan Krister [mailto:ste...@cr...] 
> Sent: Tuesday, July 25, 2006 4:12 PM
> To: lcd...@li...
> Subject: Re: [Lcd4linux-devel] display on WRAP-Board - how 
> fast is i2c? ho w good is the lpc connector?
> 
> 
> Hi Luis,
> 
> Luis.F.Correia schrieb am 25.07.2006 15:27:
> > 
> > For the sake of completeness, here's an update to the schematics:
> > 
> > The PCF is powered by +5V, but the I2C inputs are biased to
> > +3.3v, which is the correct voltage level of the WRAP board.
> 
> My datasheet says that voltage between 2.5V and 6.0V are 
> valid. Must I provide 5V also? And where to take ...

How are you powering the LCD?

>From what I've seen, all LCD's I have only +5V power, and yes, I use
an additional power for it.

FYI, i use the power supply from an external 5 1/2 enclosure to 
power my LEAF board. While I could use only the +5V supply to power
all the board, I chose to power the board with the +12V and the +5V
for the LCD and other things i may need.

> > The messages around loading the i2c bus including the scx200_acb.
> 
> There are no messages ..

That is odd...

Can you send me a CF image that you are currently using, so that 
I can test with my WRAP? Private email please. (if you get a 
message too large, let me know, i'll provide another email 
free from restrictions)


Luis Correia   
Bering uClibc Team Member

PGP Fingerprint: BC44 D7DA 5A17 F92A CA21 9ABE DFF0 3540 2322 21F6 
Key Server: http://pgp.mit.edu

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Luis.F.Correia <Lui...@se...>]

Hi! 

> -----Original Message-----
> From: Stefan Krister [mailto:ste...@cr...] 
> 
> Hi Luis,
> 
> Luis.F.Correia schrieb am 25.07.2006 17:26:
> > 
> > How are you powering the LCD?
> 
> I'm using a DOG-Module [1] which rus with 3.3V.

Good, then forget about my other power level conversion comments :)

> >> There are no messages ..
> > 
> > That is odd...
> 
> yes ..
> 
> > Can you send me a CF image that you are currently using, so 
> that I can 
> > test with my WRAP? Private email please. (if you get a message too 
> > large, let me know, i'll provide another email free from 
> restrictions)
> 
> Yes - I zip it together after breakfast. A 4MB CF will be 
> enough, I think.

I haven't got the time to test your image yet.

> Is there a bering-image I could use?

Bering-uClibc does not use an image per-se. It just boots from the
CF and reads all packages from it.

But I can prepare an image for you, once i get my stuff ready to
test. I've been fighting with I2C also.

Now i even discovered the 0.10.0 version we are packaging segfaults
on exiting... i'll have to take a good look into it, as it is difficult
to debug inside WRAP it self.

> 
> [1] http://www.lcd-module.de/eng/dog/dog.htm
> 
> MfG
> 
> Stefan

Luis

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Stefan K. <ste...@cr...>]

Hi Luis,

Luis.F.Correia schrieb am 25.07.2006 17:26:
> 
> How are you powering the LCD?

I'm using a DOG-Module [1] which rus with 3.3V.

>> There are no messages ..
> 
> That is odd...

yes ..

> Can you send me a CF image that you are currently using, so that 
> I can test with my WRAP? Private email please. (if you get a 
> message too large, let me know, i'll provide another email 
> free from restrictions)

Yes - I zip it together after breakfast. A 4MB CF will be enough, I think.

Is there a bering-image I could use?

[1] http://www.lcd-module.de/eng/dog/dog.htm

MfG

Stefan

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Stefan K. <ste...@cr...>]

Hi all,

success!

I have blinking LEDs at the pcf8574 output lines while lcd4linux is
running! My LCD is still 'dark' but that may be a other problem ...

I'm not 100% sure, but i think, that

insmod scx200_acb.ko base=0x810,0x820

was the right step.

MfG

Stefan

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Luis C. <lfc...@lf...>]

Stefan Krister wrote:
> Hi all,
>
> success!
>
> I have blinking LEDs at the pcf8574 output lines while lcd4linux is
> running! My LCD is still 'dark' but that may be a other problem ...
>
> I'm not 100% sure, but i think, that
>
> insmod scx200_acb.ko base=0x810,0x820

  Yes, that was it!

  That is why the module we use was modified in the first place. For 2.4
  kernels there was no useable module, hence the need to modify it.

  I now also have my I2C module working as well, and this time also
  powered by 3.3V, it's blue backlight module i salvaged from an old HP
  printer (HD66710). Pity it won't do any lowercase characters...

  I will need something in the lines of a uppercase_all plugin or
  something similar, that would produce proper text output (everything
  written in CAPS). Michael, any hints on this?

  Stefan, i'm also finetuning the driver a bit, try this attached file,
  where i did some minor changes and bug fixes.

Update, sf.net is forbidding .ZIP file extensions, so i'll just copy 
past my changes here.

CHANGELOG:

drv_generic_i2c.c:

The exit code was not done properly.
p.s. there is still a need to properly detect the I2C slave device, 
which i'll do in some days along with the extension for full 8bit mode 
using two PCF8574. This is of course just a plan, knowing my previous 
time-to-market failed objectives :P

drv_HD44780.c:

The second delay for 4.1ms was wrong
4bit and 8bit code decision and initialization needs to be done also here.


------------------------------- CUT HERE -------------------------------


drv_generic_i2c.c:


int drv_generic_i2c_open(const char *section, const char *driver)
{
     int dev;
     char *bus, *device;
     udelay_init();
     Section = (char *) section;
     Driver = (char *) driver;
     bus = cfg_get(Section, "Port", NULL);
     device = cfg_get(Section, "Device", NULL);
     dev = atoi(device);
     info("%s: initializing I2C bus %s", Driver, bus);
     //info("device %d", dev);
     if ((i2c_device = open(bus, O_WRONLY)) < 0) {
			error("%s: I2C bus %s open failed !\n", Driver, bus);
			goto exit_error;
     }
     info("%s: selecting slave device 0x%x", Driver, dev);
     if (ioctl(i2c_device, I2C_SLAVE, dev) < 0) {
			error("%s: error selecting slave device 0x%x\n", Driver, dev);
			goto exit_error;
     }

     info("%s: initializing I2C slave device 0x%x", Driver, dev);
     if (i2c_smbus_write_quick(i2c_device, I2C_SMBUS_WRITE) < 0 ){
			error("%s: error initializing device 0x%x\n", Driver, dev);
			close(i2c_device);
		}

     return 0;

   exit_error:
     free(bus);
     free(device);
		close(i2c_device);
		return -1;
}


drv_HD44780.c

	change init sequence around linen 995 to this:

     /* initialize display */
     drv_HD_I2C_nibble(allControllers, 0x03);
     udelay(T_INIT1);		/* 4 Bit mode, wait 4.1 ms */
     drv_HD_I2C_nibble(allControllers, 0x03);
     udelay(T_INIT2);		/* 4 Bit mode, wait 100 us */
     drv_HD_I2C_nibble(allControllers, 0x03);
     udelay(T_INIT1);		/* 4 Bit mode, wait 4.1 ms */
     drv_HD_I2C_nibble(allControllers, 0x02);
     udelay(T_INIT2);		/* 4 Bit mode, wait 100 us */
     drv_HD_I2C_command(allControllers, 0x28, T_EXEC);	/* 4 Bit mode,\ 
1/16 duty cycle, 5x8 font */


------------------------------- CUT HERE -------------------------------

Have fun.

If I can, i'll prepare a small webcam video to illustrate how slow the 
I2C bus can be, speccially with scrolling widgets like 'OS'.

Luis Correia


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Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Michael R. <re...@eu...>]

Hi Luis,

>   I will need something in the lines of a uppercase_all plugin or
>   something similar, that would produce proper text output (everything
>   written in CAPS). Michael, any hints on this?

There's already a plugin_string.c, with only a strlen() function. A
toupper() and tolower() function would perfectly fit here (mabye the
name is wrong, but I could not find a  better one :-)

> The second delay for 4.1ms was wrong
Have you got any details about this one?


bye, Michael

-- 
Michael Reinelt <re...@eu...>
http://home.pages.at/reinelt
GPG-Key 0xDF13BA50
ICQ #288386781

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Luis C. <lfc...@lf...>]

Michael Reinelt wrote:
> Hi Luis,
> 
>> You already wrote the function I need... it is inside plugin_sample.c
> 
> Oh.... I feel *so* sorry for writing a sample plugin that actually
> *makes sense* :-)
> 
>> I've already added the function and the relevant functions and will make
>> a commit to CVS.
>>
>> Some fixes to I2C handling will also be committed.
>> I'll do separate checkin's, to make things easier to track.
> 
> Thanks. I did some modifications to the string plugin (creating a new
> init() and exit() function for struppper isn't necessary, just use the
> exisiting ones), but I cannot commit at the moment, because of other
> heavy modifications not yet finished (hint: virtual rows, scrolling, ...)

I see what you mean and will do a commit to fix those. Only one init 
function is needed and we'll just register the function inside.

> But there's a problem with your patch: I get a linker error about an
> undefined function 'drv_generic_i2c_close()' in drv_HD44780.c. That's
> correct, such a function is called, is present in drv_generic_i2c.h, but
> is missing in drv_generic_i2c.c

That is the result of not being able to compile current CVS version and 
working on an older file, 0.10.0 release actually.

Nevertheless, I've already commit the fix for it.

Still unable to compile it due to some errors in "drv_HD44780.c, 
drv_LPH7508.c and drv_generic_keypad.c".

Will you need any help on those?

> 
> bye, Michael
> 

Btw, why the need for autoconf 2.59e? I pretty much remove those checks 
to be able to use autoconf 2.59 and it still compiled all the same...


Luis Correia

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Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Stefan K. <ste...@cr...>]

Hi all,

success!

I have blinking LEDs at the pcf8574 output lines while lcd4linux is
running! My LCD is still 'dark' but that may be a other problem ...

I'm not 100% sure, but i think, that

insmod scx200_acb.ko base=0x810,0x820

was the right step.

MfG

Stefan

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Stefan K. <ste...@cr...>]

Hi all,

success!

I have blinking LEDs at the pcf8574 output lines while lcd4linux is
running! My LCD is still 'dark' but that may be a other problem ...

I'm not 100% sure, but i think, that

insmod scx200_acb.ko base=0x810,0x820

was the right step.

MfG

Stefan

Re: [Lcd4linux-devel] display on WRAP-Board - how fast is i2c?

[Stefan K. <ste...@cr...>]

Hi Luis,

Luis.F.Correia schrieb am 25.07.2006 17:26:
> 
> How are you powering the LCD?

I'm using a DOG-Module [1] which rus with 3.3V.

>> There are no messages ..
> 
> That is odd...

yes ..

> Can you send me a CF image that you are currently using, so that 
> I can test with my WRAP? Private email please. (if you get a 
> message too large, let me know, i'll provide another email 
> free from restrictions)

Yes - I zip it together after breakfast. A 4MB CF will be enough, I think.

Is there a bering-image I could use?

[1] http://www.lcd-module.de/eng/dog/dog.htm

MfG

Stefan