AN3114 datasheet(23/43 Pages) STMICROELECTRONICS

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AN3114

Displaying alphanumeric characters on the LCD glass

Doc ID 16829 Rev 3

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Displaying alphanumeric characters on the LCD

glass

This section explains how to connect the LCD controller to an LCD glass to display

alphanumeric characters. It is based on the following examples:

●

STM8L1526-EVAL evaluation board using Pacific Display devices PD-878 and medium

density STM8L152xx microcontroller

●

STM8L1528-EVAL evaluation board using the custom LCD HXO5002B and high

density STM8L152xx/STM8L162xx microcontroller

4.1

PD-878 LCD glass used on STM8L1526-EVAL

The PD-878 LCD glass mounted on the STM8L1526-EVAL is an eight multiplexed digit

display from Pacific Display devices, the PD-878 (see Figure 13).

Depending on the type of LCD glass which is used, the user can select the LCD mode by

configuring the duty cycle. Each segment line can control up to four pixels. The integrated

LCD controller available in medium density STM8L152xx/STM8AL3Lxx devices can control

up to 112 LCD segments that can be divided between alphanumeric symbols and several

predefined symbols including digit, bell, low-battery symbol, arrows (left, up, right, and

down), antenna, and progress bar. Since the LCD glass has in total 128 LCD segments

(only alphanumeric characters) controlled through four COM and 32 segment lines, some of

the segment lines of the LCD glass are not connected in the standard configuration (see

Figure 14).

Alphanumeric characters are displayed using 16 LCD segments. Figure 15 shows the LCD

segments and reference letters for an alphanumeric character.

Figure 13.

Layout for the PD-878

AN3114 Datasheet(PDF) 23 Page - STMicroelectronics