Yampp-3U
Reference Manual
Contents
Version 1.10,
11/10/2005
Page 11 of 13
4.3.2.2
Display backlight (Option 1)
The white LED backlight needs a supply
voltage of 6.5v at 15ma. You can power the
backlight from the unregulated YAMPP input
power source. I.E. If you power up the
YAMPP3/U from 12V supply, you simply have
to connect VLED+ to the supply thru 330-ohm
resistor, and VLED- to the GND.
NOKIA DISPLAY
10
9
VLED-
VLED+
+12
GND
330 ohm
4.3.2.3
Display backlight (Option 2)
It’s also possible to power up the white led
with this driver module. This module can be
found on the web shop. The diagram shows
the pin connections. The VIN pin should be
connected to +5V VCC*. The PWM pin can be
connected to the pin 5 of J9 but currently the
firmware does not support the backlight
control.
PWM
GND
VIN
K (VLED-)
A (VLED+)
VIN : 3v to 5v
PWM : 0 = Off, 1 = On
4.3.3 Firmware
Step 1: Download the latest firmware in the software section of the YAMPP web page. The
firmware package you need is: “Yampp3U with color LCD firmware version 3.10b or
above”.
This version of Y3U firmware has a special definition for characters table. This definition is
“#define ROM_CHARS” located in “Constant.h” file. This option provides two ways for storing the
characters table in the player. The characters table can be stored in Flash memory of the
microcontroller or in the hard disk. If this definition is uncommented, the characters table will be
located in the flash memory of the microcontroller. Unfortunately this option will consume about
1720 bytes of code space memory. For code space problem, you can disable some other options.
By default, UART INFO and IR numerical keys are disabled.
Enabling this option is recommended according to these actions.
•
First time display connection.
•
Not sure about the setup.
•
Installation and format a new drive.
IF you need a lot of options and/or you have a code space problem, you can disable the special
definition. If you comment the “#define ROM_CHARS” definition, the characters table will be
located in the disk drive. The characters table will be loaded inside the RAM memory of the
microcontroller during startup. The display will stay dark until the initialization of the hard disk
and the file system. If something fails during initialization, you will not able to see something on
the display except if the hard disk is not in YADL format. In this case you will see the progress
bar and the player will step into the boot loader mode. Additionally, there’s no disk format
function when you select RAM character generator mode.