Power saving function

[ks]

First i want to tell that VisualTFT starts in Ubuntu Linux with Wine emulatior.
It was just a quick look, so i can't tell more about if all functions work correctly.

What i wish is that you add TFT controller standby on/off function to TFT library.
(HX8347-AppNote.pdf page 55-56)

I have got mikroMMB 18 card down to 740uA in sleep mode this far.

[slavisa.zlatanovic]

Hi!

What i wish is that you add TFT controller standby on/off function to TFT library.
(HX8347-AppNote.pdf page 55-56)

I'll pass your suggestion to our software developers.
It will be considered.
Thanks!

[Matjaz]

Is there a way to put TFT display in sleep mode? Could you please send me an example?

[slavisa.zlatanovic]

Hi!

Is there a way to put TFT display in sleep mode? Could you please send me an example?

Currently, this feature is not available in our TFT Library. However, I'll pass your request to our software developers.
It will be considered.

[ks]

Is there a way to put TFT display in sleep mode? Could you please send me an example?

-Try use LCD_RST -pin. You must init and reload lcd to get it work again.
-Clear also LCD backlight pin to turn leds off (make it output first).

These saves power a lot.

[Matjaz]

I looked around and I only have

Code: Select all

sbit TFT_RST at LATH4_bit;

If I set it to 0x00, the display really goes blank (white screen).

I can't seem to find a way to disable TFT backlight though. This functionality would be great. I have the following PINs available (according to documentation):

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extern sfr char TFT_DataPort; TFT Data Port.
extern sfr char TFT_DataPort_Direction; Direction of the TFT Data Port.
extern sfr sbit TFT_WR; Write signal.
extern sfr sbit TFT_RD; Read signal.
extern sfr sbit TFT_CS; Chip Select signal.
extern sfr sbit TFT_RS; Command/Register Select signal.
extern sfr sbit TFT_RST; Reset signal.
extern sfr sbit TFT_WR_Direction; Direction of the Write pin.
extern sfr sbit TFT_RD_Direction; Direction of the Read pin.
extern sfr sbit TFT_CS_Direction; Direction of the Chip Select pin.
extern sfr sbit TFT_RS_Direction; Direction of the Register Select pin.
extern sfr sbit TFT_RST_Direction; Direction of the Reset pin.

and none of them seems to be connected with TFT backlight. Any further ideas?

[jpc]

the schematics suggest this to be controlled by LCD-BLED which should be on LATD2_pin for the MMB24 but it does not seem to work as i do not see any change when i make that pin low.
Maybe ME can enlighten us on this one.

[Matjaz]

I found LCD-BLED in schematics for MMB18 and it is on LATH5_bit (RH5). Setting it to 0x00, 0x01 or 0xFF doesn't turn the backlight off.

[slavisa.zlatanovic]

Hi!

I found LCD-BLED in schematics for MMB18 and it is on LATH5_bit (RH5). Setting it to 0x00, 0x01 or 0xFF doesn't turn the backlight off.

You must set the appropriate TRIS register first:

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TRISH5_bit = 0;
LATH5_bit = 0;

P.S.
You might need to do this first (PIC18F87J50 MCU specific):

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  ANCON0 = 0xFF;                   // Default all pins to digital
  ADSHR_bit  = 1;                  // Enable write/read to the shared SFR ANCON1
  ANCON1  = 0xFF;                  // Default all pins to digital
  ADSHR_bit  = 0;                  // Disable write/read to the shared SFR ANCON1

[jpc]

yes! never thought of that as i was convinced it was already turned on by the library.

[Matjaz]

You must set the appropriate TRIS register first

It now works just the way I wanted. I didn't think of setting both the LAT and TRIS register to 0.