Using the Serial LCD Adaptor for LCDs

Our first crowd-funding campaign was for the Serial LCD Adaptor kits. The product page in the AusThai Shop gives you some of the details on the operation of the kit. We thought it would be useful to give a general overview of  how you might use the kit.

The obvious advantage has been stated a few times now. The number of pins you will use on your microcontroller is greatly reduced. The Serial LCD Adaptor works with three types of serial link and has two operating modes to give you maximum flexibility.

Terminal Mode

There are two modes for the UART link: terminal and native. In terminal mode the LCD acts like a mini terminal. You simply send ASCII characters and they will appear on the LCD. When the cursor reaches the end of the line on the LCD it will automatically move to the beginning of the next line. When the cursor reaches the end on the last line on the LCD it will roll over to the beginning of the first line.

Many of the ASCII control characters work as you would expect. Carriage return (CR) moves the cursor back to the beginning of the line, Line Feed (LF) moves down one line etc…

Native Mode

There are many features of the LCD  that can be accessed by using control commands. These are accessed when the LCD is operating in native mode. In native mode you can move the cursor to a specific position, control the flashing of the cursor and so on.  These commands are the same as those that are available when the LCD is used in its normal parallel mode. Details of these control commands can be found in the datasheet for the specific LCD module you are using. We will add the commonly used commands to the specification page soon.

When in native mode, in addition to the commands available in the LCD, you can control the backlight,  set the baud rate of the UART link, set the I2C address or enable/disable the splash screen.


Of the three available links the UART link is the easiest to use. The default mode used by the UART link is the terminal mode. So you can be up and running and using the LCD without ever having to learn those unusual control codes in the LCD datasheet. You can switch to and from native mode by sending a special code sequence.

The main disadvantage of using the UART link is that the link must be dedicated to LCD. In microcontrollers where there is only one UART link available this can be a significant disadvantage, This is where the SPI and I2C links become very useful.

SPI Link

When using the SPI link the LCD is always operating in native mode. You send characters or commands to the LCD. Characters are printed on the LCD screen. Commands are used to move the cursor to a specific position, control the flashing of the cursor and so on.  It is a bit more advanced but we will provide libraries which will make it easier.  We are working on libraries for Arduino as well as generic C language libraries.

I2C Link

The I2C link has the added advantage that it is easy to share this link with other devices. The default I2C address for the Serial LCD Adaptor is 0x76. This address can be changed using a control command if necessary. When using the I2C link the LCD is always operating in native mode. As with the SPI link we will provide libraries for Arduino and generic C.

If this product looks interesting to you then visit the AusThai Shop and get yourself one.

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