Data displays are very important in the world of microcontrollers. With modern graphic LCD displays, one can design smart-looking products. But in some cases the »classic« 2x16 alphanumeric LCD or even 7 segment LED display is better-suited. If you have a limited number of I/O pins on your microcontroller, you might even want to connect your LCD via an SPI interface. All this is covered in this chapter.
Pick the right display and make sure that your product will stand out!
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Written by Jurij Mikeln
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Displaying text on an LCD is something that has always attracted newbies to programming. However, this involves many tasks which are less appealing to the newbies. To display data on an LCD, you have to perform 16 tasks if programming in asembler
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Last Updated on Wednesday, 01 August 2012 14:37 |
Written by Jurij Mikeln
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Most of us are familiar with the graphical LDCs used in our cell phones. Many years ago, the first cell phones used very small 2x16 character LCDs, but quickly cell phone manufacturers started to use graphical LCDs. In the 2000, we obtained a graphical LCD (128x 64 pixels) and Mr. Mitrović published a series of articles in which an AT89C2051 was used to drive the graphical LCD. For that time it was an astonishing project, since the programmer had to calculate the co-ordinates of each pixel on the graphical LCD.
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Last Updated on Tuesday, 04 June 2013 13:38 |
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Written by Jurij Mikeln
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Not long ago, I needed to drive multiple LCDs. There were several possibilities available. I could have used multiple microcontrollers – one for each LCD. Or I could choose a microcontroller with more output ports. Neither of the possibilities seemed economical or technically justified. My colleague Vlado showed to me a nice way to drive LCDs via the SPI bus [1]. Doing so also required a special library [1].
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Last Updated on Wednesday, 01 August 2012 14:47 |
Written by Vladimir Mitrović
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Figure 1 shows a schematic diagram of the 4-character 7-segment display module. The drive method is a multiplexed one: connecting pins of all segments of the same name (on each of the four digits) are connected together, to minimize the number of connecting wires as well as the number of microcontroller I/O pins needed. In such a design, the digits are activated sequentially, in quick succession. This process is known as multiplexing.
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Last Updated on Wednesday, 01 August 2012 14:38 |
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