LK404-25-E Matrix Orbital, LK404-25-E Datasheet - Page 16

• Manufacturer Part Number: LK404-25-E
• Description: LCD Character Display Modules 40x4 Grn/Yel Ext Temp
• Manufacturer: Matrix Orbital

Specifications of LK404-25-E

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.3 The display module is communicating, however text cannot
4 Communications
4.1 Introduction
4.1.1 I
single I
resistors, with a nominal value of 1K to 10K, are placed on the SCL and SDA communication lines coming
from pins two and three of the Data / Power Connector respectively. Data responses by the module are
automatically output via RS232, in case the host will be querying the module, it is necessary for the host
to inform the module that its responses are to be output via I
254 /160 / 0 to turn off auto transmission of data in RS232. This will keep the data in the buffer until the
master clocks a read of the slave. The I
LK404-25 uses 8-bit addressing, with the 8th or Least Significant Bit (LSB) bit designated as the read/write
bit, a 0 designates a write address and a 1 designates a read address. The default read address of the display
module will be 0x51, whereas the write address is 0x50 by default. This address may be changed by using
cmd 254 / 51 / <address>. The LK404-25 should only be sent addresses that are even (LSB is 0). When the
Matrix Orbital
• Third, ensure that the host system and display module are both communicating on the same baud rate.
• If you are communicating to the display via I
• Finally, you may reset the display to it’s default settings using the Manual Override Jumper, see
• A common cause may be that the contrast settings have been set to low. The solution to this problem
The commands listed in this chapter describe how to configure data flow on the LK404-25.
The LK404-25 is capable of communicating at 100 KHz in I
The default baud rate for the display module is 19200 bps.
address. The default slave address for the display module is 0x50.
Section 2.6 on page 9.
is to adjust the contrast settings. The default setting that will work in most environments is 128.
2
be displayed.
C communication line. However, in order to communicate via I
NOTE I
NOTE Optimal contrast settings may vary according to factors such as temperature, view-
ing angle and lighting conditions.
If you are unable to resolve any issue please contact Matrix Orbital. See 14.6 on page 53
for contact information.
2
C Communication Summary
2
C communication will always require pull up resistors.
2
C data lines operate at 5V normally or 3.3V for -1U style units. The
LK404-25
2
C please ensure that the data is being sent to the correct
2
C. This can be done by sending command
2
C mode, with 127 units addressable on a
2
C you must first ensure that pull up
12