LCD0821 Matrix Orbital, LCD0821 Datasheet - Page 11

• Manufacturer Part Number: LCD0821
• Description: LCD ALPHA/NUM DISPL 8X2 YW/GN BK
• Manufacturer: Matrix Orbital
• Series: LCD0821r

Specifications of LCD0821

• Display Type: TN - Twisted Nematic
• Display Mode: Transmissive
• Number Of Digits/alpha: 16
• Outline L X W X H: 58.00mm x 32.00mm x 21.00mm
• Viewing Area: 38.00mm L x 16.00mm W
• Backlight: LED - Yellow/Green
• Display Format: 8 x 2
• Character Size: 5.55mm H x 2.95mm W
• Character Format: 5 x 7 CURS
• Voltage - Supply: 5.0V
• Dot Size: 0.55mm W x 0.55mm H
• Interface: I²C, RS232, TTL
• Operating Temperature: 0°C ~ 50°C
• Character Count X Line: 8 x 2
• Module Size (w X H X T): 58 mm x 32 mm x 25 mm
• Fluid Type: STN
• Background Color: Yellow / Green
• Backlight Type: LED Yellow / Green
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 635-1009; LCD082

The module is supplied with jumpers J1 and J2 installed, which gives a RS-232 baud rate of 19200 and an
I
2.1.6 I
I²C communications runs at 100 kBps and supports up to 16 units on a single communications line. The
I2C data line operates on 5 volt CMOS levels.
The idea of ACK is to indicate when the data has been received correctly. ACK does not indicate data
incorrectly received. ACK simply fails to indicate when data is correctly received. Clearly, this is of limited
usefulness and even less so with Matrix Orbital modules. Matrix orbital modules are not capable of failing
to acknowledge an incorrectly received byte in response to that bytes transition. They are only capable of
failing to acknowledge the bytes following the byte, which was not received. To fully understand the
reasons for this one needs to understand something about how a Matrix Orbital module processes data.
Basically the reason why a Matrix Orbital module might fail to receive a byte correctly is that it was unable
to process the byte previous before the failed byte was transmitted. Because the module cannot possibly
know that it would be unable to store the byte before the next byte was received it cannot know to not ACK.
The reason for this situation in deference to situations you might be familiar with (i.e. memory chips, etc…)
is that the Matrix Orbital module employs a microprocessor to perform these data storage functions. A
memory chip takes care of these things entirely with in hardware subsystems that operate at the same speed
as the transmission themselves.
LCD0821 rev 2
2
C address of 0x5C.
RS-232 port: J0, J1, J2 - control baud rate. RS-232 format is 8N1 (8 bits, no parity, one stop bit)
I²C port: J0, J1, J2, J3 - sets slave peripheral address
2
C Communications
Baud Rate
19200
19200
1200
2400
9600
1200
2400
9600
Slave Address
5AH
5CH
5EH
6AH
6CH
6EH
50H
52H
54H
56H
58H
60H
62H
64H
66H
68H
11
out
out
out
out
out
out
out
out
J3
in
in
in
in
in
in
in
in
out
out
out
out
out
out
out
out
J2
in
in
in
in
in
in
in
in
out
out
out
out
out
out
out
out
J1
in
in
in
in
in
in
in
in
out
out
out
out
out
out
out
out
J0
in
in
in
in
in
in
in
in