LK202-25-R-VPT Matrix Orbital, LK202-25-R-VPT Datasheet - Page 21

• Manufacturer Part Number: LK202-25-R-VPT
• Description: LCD ALPHA/NUM DISPL 20X2 BK RED
• Manufacturer: Matrix Orbital

Specifications of LK202-25-R-VPT

• Display Mode: Transmissive
• Number Of Digits/alpha: 40
• Outline L X W X H: 116.00mm x 37.00mm x 25.73mm
• Viewing Area: 82.20mm L x 18.20mm W
• Display Format: 20 x 2
• Character Size: 5.55mm H x 3.20mm W
• Character Format: 5 x 7 Dots
• Voltage - Supply: 5VDC
• Dot Size: 0.60mm W x 0.65mm H
• Interface: I²C, RS232, TTL
• Operating Temperature: 0°C ~ 50°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Display Type: -
• Backlight: -

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
LK202-25 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 LK202-25 should only be sent addresses that are even (LSB is 0). When the
I
0 for an I
(0101 0001), since the LSB has to be 1 for an I
this Phillips I
When writing to the display module, the display will respond with a ACK when the write has successfully
been completed. However if the buffer has been filled, or the module is too busy processing data it will
respond with a NAK. When performing a multiple byte read within one I
the slave should be followed by an ACK to indicate that the master still needs data, and a NAK to indicate
that the transmission is over.
tions when writing I
sent (only needs to be sent once, so this can be done somewhere in init): 254 / 160 / 0 this command puts
the reply data in the I
output buffer, query commands that reply with more than 16 bytes cannot be read (eg cmd Get FileSystem
Directory)
Matrix Orbital
2
C master wishes to write to the display, the effective address is $50 (0101 0000) , since the LSB has to be
The commands listed in this chapter describe how to configure data flow on the LK202-25.
The LK202-25 is capable of communicating at 100 KHz in I
If we take a standard Phillips 7 bit address of $45 (100 0101), Matrix Orbital’s LK202-25 would describe
The unit does not respond to general call address ($00).
When communicating in I
The LK202-25 has some speed limitations, especially when run in I
* to be able to read the replies of query commands (eg. cmds 54, 55) the following command must be
* 3ms delay between the read commands
* 625us delay in between data bytes within a transaction is necessary
* 375us between transactions is necessary
2
C communication line. However, in order to communicate via I
2
2
C master write. When the I
C Communication Summary
2
C address as $8A (1000 1010). The read address would be $8B (1000 1011).
2
C code:
2
C output buffer instead of the RS232 output buffer. Please note that due to a 16 byte
2
C the LK202-25 will send an ACK on the 9th clock cycle when addressed.
2
2
C master wishes to read the LK202-25, the effective address is $51
C data lines operate at 5V normally or 3.3V for -1U style units. The
2
C master read.
LK202-25
2
C. This can be done by sending command
2
C mode, with 127 units addressable on a
2
2
2
C you must first ensure that pull up
C mode. Here are some considera-
C transaction, each byte read from
17