Difference between revisions of "Open Source LED Dot Matrix Clock"

Outline

• Project：Microduino dot matrix cascade clock
• Objective：Real-time display clocks and characters.
• Difficulty：Medium
• Time-consuming：2 hours
• Maker：peng
• Introduction:
  • Cascade the four Microduino DotMatrix module.
  • Use a Bluetooth module to calibrate the time that the dot matrix displays through the mobile APP.
  • You can also send any character to dot matrix module to display through APP.

Bill of Materials

Principle of the Experiment

• Features of the Microduino-Dot Matrix module：
  • The module is 8x8 dot matrix, and the size is 60mm*60mm；
  • The color display quality of each dot is 24 bits, and the color display effect is 32k;
  • Support the IIC communication protocol. The IIC address can be set（1~64）. The dot matrix sequence adopts the plane rectangular coordinate system, which is easy to control;

• Use Microduino-BLE Bluetooth module to communicate with the mobile phone:
  • The mobile APP sends the string to core module through the Bluetooth module, and display on the dot matrix module.

Program Download

• Please keep to download and download the Microduino official latest IDE.
• Download a program from the link below：Dot-Matrix-Clock.ino

Programming

• Overlay the Microduino-Core and Microduino-USBTTL together.
  • Connect the Microduino-USBTTL with USE cable and prepare to upload the programs.

**Note：Please upload programs before stacking all modules together.

• Open Arduino IDE for Microduino environment. （The reference to set up：AVR Core：Getting started）
• Click [Tool], and confirm board card（Microduino-Core）, and processor（Atmega328P@16M,5V） selected correctly, and select the corresponding port number (COMX).
• Click [File]->[Open], browse to the project program address, and click“Dot-Matrix-Clock.ino” to open the program.
• After all these items are correct, click "→" to download the program to the development board.

Installation

Step1: Insert structure B2 vertically into structure B1. Use structure B3 to connect structure A1 and structure B1.

Step2: Use structure B4to jam the structure A1 and structure B1 .

Step3: To change the IIC address of the dot matrix module, you can refer to [The method of setting the IIC address of the dot matrix module ] tutorial. Connect the dot matrix modules of which the IIC address have been changed in order that from left to right according to to defined address, to complete the cascade. Stick piece of four double sides adhesive tape on the back of structure C1 equidistantly, and stick Microduino-Dot Matrix to structure C1（put the side with letters of the dot matrix down）successively. As the following figure, reserve the cable of the key end interface of the module in order to connect the IIC interface of Microduino-Cube-S1.

Step4: Use structure B3 to connect structure C1 and structure A1,B1.

Step5: Use structure B5 to jam structure B3. Stack the following modules on the Microduino-Cube-S1. Microduino-Core Microduino-USBTTL Microduino-RTC Microduino-BT

Step6: Connect the module Microduino-Dot Matrix to the IIC interface of Microduino-Cube-S1. Use nylon screws to fix Microduino-Cube-S1 on the back of structure C1.

Operating Instruction

• APP file download File:Blueclock.zip

Bluetooth Connection

Make sure that the phone Bluetooth has been open, then use APP to search the Bluetooth device named as “Microduino”. After connecting successfully, you can control it. Calibration Time In view of RTC module will lost time long time without power supply, we have added that use APP to adjust time, through the Bluetooth module. Clicking the “sync time with phone” button can adjust the time of the dot matrix.

Display Text

In the input field write‘hello microduino’, and click “send message”, then the characters that you have written will be displayed on the dot matrix screen.

Code Instruction

Code to loading：File:Dot Maxtrix Clock.zip

Dot Matrix Cascade

 uint8_t Addr[MatrixPix_X][MatrixPix_Y] = {                 
{ 64, 63, 62, 61}};       

Define the IIC addresses of the four Dot Matrix modules as 64, 63, 62, and 61, and the arrangement type is 1x4.

Bluetooth

 while (mySerial.available()) {...}

It is effective when there is a serial port data.

  mySerial.read()

Red the data which is transferred by the UART.

   if (c == 't' && buffer_num == 0 && !buffer_sta_d)
     buffer_sta_t = true;
   if (c == 'm' && buffer_num == 0 && !buffer_sta_t)
     buffer_sta_d = true;

Judge it is date or time data.

 strstr((char *)buffer, "t")

Return the address where the "t" character first appears in buffer.

 sscanf((char *)strstr((char *)buffer, "t"), "t%d,%d,%d,%d,%d,%d", &sta[0], &sta[1], &sta[2], &sta[3], &sta[4], &sta[5]);

From the address where the "t" character first appears in buffer, read the value according to the %d type, and write into sta[].

 bleUpdata()

Transfer data through UART, only by clicking the button on your mobile phone to send the specified character. If loosing, it will send character“0”. So without press, it will always show time.

RTC

  rtc.getDate();
  rtc.getTime();
  setTime(rtc.getHour(), rtc.getMinute(), rtc.getSecond(),  rtc.getDay(), rtc.getMonth(), rtc.getYear())

Get the date and time data of rtc.

  rtc.setDate(day(), weekday() , month(), 0, year() - 2000); //day, weekday, month, century(1=1900, 0=2000), year(0-99)
 rtc.setTime(hour(), minute() , second()); //hr, min, sec

Set by hour, minute, second, day, month, and year format.

Display

  display.print(second() % 2 ? " " : ":");

The second flashes, after being used justify whether the second can be exactly divided by 2. If it can, show it. If not, don’t show.

 display.getDeviceAddr(a)

Get the IIC address of the device.

 display.getWidth()，display.getHeight()

Return the X,Y coordinates.

 display.setLedColor(x, y, random(0, 255), random(0, 255), random(0, 255))

Set the color of each LED randomly.

 display.clearDisplay()

Clean up the screen.

 display.setColor(X,Y,Z)

Set the color of the full screen X：Red Y：Green Z：Blue

 display.writeString("string", MODE, time ,z)

string：any string. MODE：MODE_H displays characters horizontally. /MODE_V displays characters vertically. time：The displayed time（the flow velocity of the characters on the screen）. z：X/Y coordinate.

Through reading the RTC color, display the specific values in the form of coordinates.

FAQ

• Q:How can I know the IIC address of the Microduino-Dot Matrix module？
  • A:Refer to [The method of setting the IIC address of the dot matrix module] tutorial.
• Q:What order do the lattice modules connect according to？
  • A:Connect from left to right according to the IIC address order that is set for Microduino-Dot Matrix module .
• Q:How to know whether the mobile phone has been connected with the Bluetooth module？
  • A：When there is connected displayed on the top left in the APP interface, it is connected successfully.
• Q:What is the meaning of the jumper of the Bluetooth module？
  • A:The Bluetooth module used in this tutorial is the default soft serial port mySerial(4,5), so don’t need to jump line. You can refer to the blue module configuration for in-depth knowledge of the Bluetooth. Microduino- BLE pin elucidation.