Timer

ddllxxrr

Timer [Copy link]

 

Project Name: Timer

Project Introduction:

In my daily life, I think that besides clocks, timers are also very useful, such as cooking and steaming buns. I want to make a timer that is low in cost and easy to use. It can be powered by a 5V USB charging wire. It is powered when in use and can be removed when not in use. In addition to the basic functions, I also thought of using other functions of the chip as an extension.

The expandable functions are:

1. Using the RTC function, you can compile a program to expand it to a clock.

2. This design has a serial port that can communicate with WIFI, so it can be expanded to WIFI control timing.

This time only realizes the most basic function---timer. The longest time that can be set is 1 hour and 60 seconds.

System Function Introduction:

In order to reduce the cost, the pins are used directly to drive the 1-inch digital tube. At the beginning, there were too many wires and I gave up a bit. Later, after connecting them and lighting up, the effect was pretty good. The program is like this. At the beginning, each pin and each timer are initialized. This design uses two timers, one for digital tube scanning and one for timing. The display function is completely driven by pins. The minutes are placed in the first two digits of a 4-unit array, and the seconds are placed in the last two digits of the array. When powered on, it displays 0000. Only when the minutes and seconds are set and the third key is pressed, can it be started. When the timing is completed, an alarm will be issued.

System block diagram:

[attach]415 266[/attach]

Flow chart:

Photo:

Code:

MYLED.rar (241.47 KB, downloads: 24)

2019-5-26 11:05 上传

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[size =4]Video:

https://training.eeworld.com.cn/course/5150/learn?preview=1#lesson/20216 https://training.ee world.com.cn/c…view=1#lesson/20216 Postscript: Although it was made this time, I think it is better to find a digital chip to drive the digital tube in the future. It costs a few yuan each. This time I spent a lot of effort and was about to give up. But after trying it, the display is OK, but it doesn't look good when pressing the button. There is no way. As for the timing, it is very accurate. I measured it with a mobile phone and it was exactly the same.

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maychang

"The display is OK, but it doesn't look good when pressing the buttons." Is it because the display and buttons share pins?

sf116

maychang posted on 2019-5-26 11:35 "The display is OK, but it doesn't look good when pressing the buttons." Is it because the display and buttons share pins?

The button processing is dead, the MCU is completely occupied, and the digital tube refresh is delayed.

maychang

sf116 posted on 2019-5-26 14:53 The key processing is waiting, the MCU is fully occupied, and the digital tube refresh is delayed.

"The key processing is waiting, the MCU is fully occupied, and the digital tube refresh is delayed." If so, it is a software programming problem. Why not use a timer interrupt to check the key and refresh the display at the same time?

ddllxxrr

maychang posted on 2019-5-26 11:35 "The display is OK, but it doesn't look good when pressing the button." Is it because the display and the button share the same pin?

No, it's what the person below said, that when pressing the button, the display is delayed

ddllxxrr

sf116 posted on 2019-5-26 14:53 The key processing is dead, the MCU is completely occupied, and the digital tube refresh is delayed.

This can be considered, there is room for optimization in the future

lightxixi

OP, don’t forget to upload the word document of your work!

ddllxxrr

lightxixi posted on 2019-6-11 15:44 OP, don’t forget to upload the word document of your work!

It can no longer be uploaded. No modification is allowed.

lightxixi

ddllxxrr posted on 2019-6-11 19:46 It can no longer be uploaded, and modification is not allowed

Yes, please add my QQ: 454909423, give it to me through QQ

lightxixi

lightxixi posted on 2019-6-12 16:16 Yes, please add my QQ: 454909423, and give it to me through QQ

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