matrix clock

Intelligent electronic matrix clock

Note: The production of this electronic clock has been completed, and the effect is as shown in the video resources given below

       All information about the project is placed in the project attachment.

1. Introduction to electronic matrix clocks

        This electronic clock needs to be configured through the mobile phone software EspTouch. When a battery is installed, the time information can be displayed normally even after powering off and on again after the network distribution. It is controlled by the wifi module ESP8266-12S and programmed with Arduino. The time information obtained from the Alibaba Cloud timing service platform is converted into SPI communication through the program and transmitted to control four 8*8 dot matrix driver chips MAX7219. Each MAX7219 acts on the corresponding 8*8 dot matrix screen independently, and RST The buttons and SW2 button are for more convenient downloading of programs and resetting the ESP8266 module.

2. Introduction to the schematic diagram

        We divide the entire circuit schematic diagram into two parts, hereafter referred to as part A (main board) and part B (top display board)

Part A is mainly divided into

      (A1): Download program;

                     For the download program part, we use the CH330N chip (the original author used CH340N, there is not much difference). It is not much different from the ordinary USB to TTL chip. At the same time, it does not need to use an external crystal oscillator. It is a SMD package and the number of pins is 8P, less pin count, so we chose it

                     From the data sheet, we know that because the ESP8266-12S download program has strict requirements (first the module must be in reset state, then the module's IO0 port must be at low level, and finally released), so we designed a reset button and download Program buttons, respectively RST and SW2

      (A2): Power Management:

                     The power management uses the AMS1117DC-DC chip, which is a chip package. The chip input port is equipped with a 100uF tantalum electrolytic capacitor and a 0.1uF non-polar chip capacitor. Their function is to filter out some AC components in the input power supply, and It has the function of storing electrical energy, and at the same time it can protect the normal use of the chip and extend its life; the chip output port is also equipped with the same capacitor as the input port, and its function is similar to the input capacitor, preventing subsequent circuit power supply fluctuations, and the capacitor is better than a reservoir. The role of surge protection.

                     Of course, there is a separate battery CR1220 next to the DS3231 high-precision clock management chip. Since the power supply fails to keep the clock running, the DSS3231 chip is equipped with a dedicated battery for power supply, and it is powered by BAT54C (similar to the "OR gate" in digital circuits) Select the input power supply (you can choose battery power supply or power supply, the default is power supply, depending on the voltage difference between the two)

      (A3): Networking module:

                     The networking part uses the ESP8266-12S module. During normal operation, the external circuit is available from the data sheet. Its main function is to connect to the network and regularly access the Alibaba Cloud timing service platform to obtain the current time information and calibrate it. At the same time, the internally written program will obtain The arrival time information is converted into SPI communication protocol data through program algorithm and sent to the cascaded dot matrix driver chip for driver display.

Part A is mainly divided into:

      (B1): Data processing:

                     The data sent from the chip is first transmitted to the first MAX7219 chip ( multi-bit LED display driver ). Through the shift operation, when the output data is high level, the corresponding LED lights in the LED matrix (common cathode) are lit to achieve Function to display corresponding data

3. Circuit design ideas

         Observing the circuit diagram, we can find that two connection methods are used at the USB interface, namely TYP-C and micro port. They are placed symmetrically, which not only makes it more convenient for users to use, but also makes the circuit safer and more reliable (when placed symmetrically , if the TYP-C data cable is inserted, the micro interface cannot be used. If the micro interface is used, the TYP-C interface cannot be used, which has a restrictive effect, but also allows users to choose the interface they want to use.)

          The circuit board has rounded corners. The rounded corners of the circuit board not only make it easier to use, but also improve the safety and aesthetics. This is also the product value of this matrix clock. At the same time, the wifi antenna part is also improved. Hollowing out and rounded corners, if placed during use or carrying, the right-angle slot between the PCB and the module may catch on clothing or skin surface, causing damage, etc.

          The connection between the motherboard and the top plate is made by using pin headers and female headers, so the height limit is mainly related to the pin headers and female headers. If some friends think the height is higher, they can use a rigid-flexible PCB or connecting wire to design the connection. , but the main idea remains unchanged

4. Product appearance design

          The top surface of the product uses a 4mm transparent acrylic board. The mainboard PCB and the top PCB are connected using 11mm copper pillars. The top PCB and the acrylic board use 6mm through-hole copper pillars. There are a total of 8 M3 screws on the top and bottom. to fix

5. Distribution network

          Download the program. Use Arduino to download the program. After clicking download, wait for the software to be compiled. Press the reset RST button for 1 second, then hold down the SW2 button, then release RST, and finally release SW2. Wait for the download to be successful.

          First, install the EspTouch software on your mobile phone (download from Espressif Systems official website), then connect to your home WIFI (not 5G, choose 4G--2.4Gwifi), turn on location positioning, enter the wifi password, power on the device, and click the software "One-click configuration" "Network", wait a moment and press the RST button

HACK LABS MatrixClock                                                                                 

Author: HACK Laboratory                                                                                     

YouTube ID: HACK Lab, welcome to subscribe https://www.youtube.com/channel/UCxFY1FcIYK9d7riTvIh6eiA                                                         

HACK_CLOCK is a free download and may be used, modified, evaluated and

distributed without charge provided the user adheres to version three of the GNU

General Public License (GPL) and does not remove the copyright notice or this

text. The GPL V3 text is available on the gnu.org web site

Author: HACK Laboratory                                                                                        

Station B ID: HACK Laboratory Welcome to subscribe https://space.bilibili.com/395145107         

The following is the link address of the HACK laboratory matrix clock video

https://www.bilibili.com/video/BV1s54y1R77t