Dot Matrix LED Display with CloudX (Part II) CloudX
Let's further advance our skill with respect to how to use the Dot-Matrix LED Display. Here, we’ll be using the ever handy shift-register IC chip in conjunction with some CloudX libraries specifically meant for ease of handling the display unit. The circuit connection remains as much simple as possible; and we’ll be making use of the breadboard to actualize that.
So far, we’ve learnt how: to blink a simple LED via CloudX's output, to use a switch to control LED on and off states via CloudX digital input, to use LED 7-segment display, to use a shift-register IC to control an array of LEDs and to use the dot-matrix LED display with CloudX. In this lesson, we'll be implementing message display using an 8x8 dot-matrix display module.
List Of Materials Needed
(The material full kit can readily be sourced via this link.)
- (i) CloudX Microcontroller and Softcard
- (ii) Dot-Matrix LED Display
- (iii) 74HC595 Shift-Register IC Chip x 2 units
Step 1: Build The Circuit
We’re using the LED display module labeled 1088BS. Below are the pin-out and the internal connection map. So, refer to your manufacturer datasheet to verify your own, in case you happen to be using another type.
As clearly illustrated in the schematic diagram below, one shift-register goes for the matrix-display row control while the other handles column control. The first shift register chip has its pins 11, 14 and 12 interfacing with the microcontroller pins P1, P2 and P3 respectively; whereas the second shift register pins: 11 and 12, interface with the microcontroller pins: P1 and P3.
Double click on the dot-matrix display unit on the simulation software (Proteus) –if you’re using the green display variant, to configure the display as thus:
Meanwhile ─continuing with the general circuit, power can be sourced to the board either via the USB Softcard; or via connecting an external power supply (between 7 – 12 VDC) to the VIN pin of the microcontroller board.
Refer to the table below to check out the details of the rest of other necessary connections.
Step 3: Build The Source Code
The impressively simple code that’ll run our project is as follows:
DotMatrix_setting(1, 2, 3, 8); //DAT, CLK, LAT, displaySize
DotMatrix_scrollDisplay("Hello,World! ", 10); //scroll speed, Text
We cannot just agree less that the level of code simplification here is really magnificent! Just about two lines of code, you get your matrix display happily glowing away.
The “dot-matrix setting” function call seen in the set-up section takes in the parameters:
- - Microcontroller pin the register Clock pin is interfacing
- - Microcontroller pin the register Data pin is interfacing
- - Microcontroller pin the register Latch pin is interfacing
- - Display column size in use
Step 4: Compile The Code
The source file is, at this very material time, compiled to obtain our hex file needed for the next stage.
For further details on how to compile the code into an executable (hex) file, you can refer to this link.
Step 5: Burn In The Hex Code File
At this juncture, the hex file has to be burnt into the microcontroller, bringing to an end our design process.
For further details on how to load the code into the microcontroller, you can refer to this link.
Step 6: Power Up The Project
The project is finally powered up; and it comes on fully alive as expected!
Now that we’ve further explored dot-matrix LED display in a much more simplified and functional fashion, you’re somewhat challenged to try your already garnered skill on the other dot-matrix CloudX function-calls.
Here (temporarily) grinds to a halt the Newbie series. So, you're encouraged to follow other project lessons on this website to further perfect your hands, and hence learn the rope of Embedded Systems Designs. Godspeed.