Build your own Bluetooth news ticker

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Example news ticker Example news ticker

Supplies

Arduino Uno R3 - clone In stock Or an Arduino Nano € 12,40 MAX7219 4x Dot matrix module In stock This is the display, you need at least 1, 2 is even better! € 8,40 HC-06 Bluetooth module met adapter In stock This is the HC-06 Bluetooth Slave, you need 1 € 7,00 5.6KΩ Metal film resistor 1 / 4W - 100 pieces In stock The voltage divider for the Bluetooth module € 1,20 10KΩ Metal film resitor 1/4W - 10 pieces Out of stock The voltage divider for the Bluetooth module € 1,45 Mean Well SGA12E09-P1J power supply - 9V 1,33A In stock For extra power, USB cannot supply enough € 12,35 DC socket built-in 5.5 mm x 2.1 mm - 5 pieces Out of stock € 2,05 Total € 44,85

The schedule:

The schematic shows how everything should be connected. If you already get a spinning feeling from all those wires, don't look too much at the whole, but try to consider and connect the modules one by one. You'll see that it's not too bad.

The schematic shows only one quadruple dot matrix LED module, in reality you can link two together for a double width!
Message board connection diagram Message board connection diagram
The bluetooth module does require a little extra attention. The Bluetooth communication signals (TX and RX) work at 3.3 volts, while the Arduino works with 5 volts. The two resistors will reduce the 5 volts from Arduino to about 3.3 volts.

The nutrition:
You can see that a 5 volt power supply is used. You have to. An Arduino connected to USB cannot supply enough current to power the LED matrix, especially with a double matrix.

Arduino Library and Sketch:

The Arduino sketch uses two external libraries, to install these, search for MD_MAX72xx in the library manager. Then install MD_Max72xx and MD_Parola
Ticker USB Arduino Library Ticker USB Arduino Library
Set the right module:
After installing the libraries, we need to tell the MD_Max72xx library which led matrix module we are using.

Locate the file on your hard drive: MD_MAX72xx.h
(probably in the folder C:\Users\your name\Documents\ Arduino \libraries\MD_MAX72XX\src\)

The Arduino Sketch:

Then we can now load the sketch.
Copy the sketch and paste the code into the Arduino software, select the correct com port and type Arduino and press upload!
If all is well (and why not?) you will now see the message “Hello, please send a new message over bluetooth”. So it's high time to install the Android App on your phone and send a new message via Bluetooth!

The Android App:

To change the text on the news ticker we need a Bluetooth terminal program, for example the Serial Bluetooth Terminal from Kai Morich, via the AppStore.
SerialBluetoothTerminal SerialBluetoothTerminal
The operation of the App is fairly self-explanatory, but in the video I show it step by step.
bluetooth terminal bluetooth terminal
Attention: Apple's iOS cannot connect to the used bluetooth module, so this only works with Android devices.

watch the video

Are there still ambiguities? You can take a closer look at everything in this video.

Posted by Website | Youtube Bart Venneker is an electronics hobbyist and makes educational videos about electronics, Arduino and 3d printers.

Comments

The Netherlands Ad Laat
Unfortunately, the adjustments cannot be found in the library, which means that the ticker does not work, which is a shame! Could a different version have been used? Greetings, Ad de Laat
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