### Project 14 Counter

**1. Description**

Arduino 4-bit digital tube counter can record numbers within 0~9999. It features display speed, count mode adjustment as well as reset function. This module is wildly applied in real-time counter (such as button-press and DC motor rotation count), gaming and experiment equipment.

**2. Flow Chart**

![](media/A172.png)

**3. Wiring Diagram**

![](media/A173.png)

**4. Test Code**

1. Drag the two basic blocks.

![](media/A174.png)

2. Set the button pin to “input”.

![](media/A175.png)

3. put a "variable" block. Set the variable type to int and name to item. Assign 0 as its initial value. 

![](media/A176.png)

4. Drag an "if" block from “Control” (it executes only when its condition is satisfied). Put a “Button pressed” block from “Button” to the condition box(the hexagon one) and set the pin to IO19. Drag a "variable mode" block and put it after "then", and define it as "item" and set the mode to "++".

![](media/A177.png)

5. Repeat step 4, but set the interface to IO18 and mode to "– –".

![](media/A178.png)

6. Drag another "if" block from “Control” and define its condition that "interface IO17 button was be pushed?". Put a variable setting block after "then" and set the "variable by 0".

![](media/A179.png)

7. Drag a "if" block from “Control”. Find the "＞" block in “Operators” and fill the left blank with "variable item" and the right with "9999". Also, put a variable setting block after "then" and set the "variable by 0".

![](media/A180.png)

8. Drag a "TM1650 display" block from "Digital tube" and set the displayed string to "variable item" block. Finally, don't forget to add a 0.2s delay. 

![](media/A181.png)

**Complete Code:**

![](media/A182.png)

**5. Test Result**

After connecting the wiring and uploading code, press green button to add 1, yellow to minus 1, and red to reset. 

**6. Code Explanation**

**">"** block is used for judgment between two values. These two blanks can be replaced with either numbers or variables. 

![](media/A183.png)