Example 15: Seven-Segment Display (TM1637)

Experiment Overview

Control a 4-digit seven-segment display via TM1637 driver chip to show numbers, temperature and other data. FastBee has a built-in TM1637 peripheral type (type: 47), supporting numeric display and custom segment codes.

Hardware Wiring

Board Label	GPIO Pin	Connected Device
CLK	GPIO18	TM1637 clock line
DIO	GPIO19	TM1637 data line

TM1637 uses a two-wire protocol (I2C-like), powered by 3.3V or 5V.

JSON Configuration Example

{
  "peripherals": [
    {
      "id": "tm1637_01",
      "name": "TM1637 Seven-Segment",
      "type": 47,
      "enabled": false,
      "pins": [18, 19],
      "params": {
        "brightness": 3
      }
    }
  ]
}

Parameter Description

Parameter	Description	Range
brightness	Display brightness	0~7

Peripheral Execution Linkage

Scenario 1: Periodic Temperature Display (Timer Trigger)

Function: Read temperature sensor every 2 seconds and display on seven-segment display

Web Interface Configuration Steps

Step 1: Ensure temperature sensor is configured

• Peripheral ID: dht11_sensor
• Type: DHT11 temperature/humidity sensor

Step 2: Create Rule

1. Click left menu Peripheral Configuration → Switch to Peripheral Execution Management tab
2. Click New Rule button
3. Fill in basic configuration:
   • Rule Name: Display Temperature
   • Report Data: ✅ Enable
   • Enabled: ✅ Enable

Step 3: Configure Trigger

1. Click Add Trigger button

2. Fill in trigger configuration:

   Field	Value	Description
   Trigger Type	Select Timer Trigger	Periodically update display
   Timer Mode	Select Fixed Interval	By millisecond interval
   Interval Time	2000	Update every 2 seconds

Step 4: Configure Action

1. Click Add Action button

2. Fill in:

   • Action Type: Select Display Value
   • Target Peripheral: Select tm1637_01
   • Data Source: Select sensor temperature value

3. Click Save button

---

Scenario 2: Display Time (Timer Trigger)

Function: Update seven-segment display with current time every second (with colon blinking)

Web Interface Configuration Steps

1. Create rule, name: Display Time
2. Trigger configuration:
   • Trigger Type: Select Timer Trigger
   • Timer Mode: Select Fixed Interval
   • Interval Time: 1000 (1 second)
3. Action configuration:
   • Action Type: Select Display Time
   • Target Peripheral: Select tm1637_01
   • Show Colon: ✅ Enable (colon blinking)
4. Click Save

Seven-Segment Display Reference

Action Type	Function	Use Case
Display Value	Show numbers (-999~9999)	Temperature, humidity, counts, etc.
Display Time	Show clock (HH:MM)	Real-time clock display
Display Segment	Custom segment code	Special symbols

Notes

1. Pin Order: First pin in the array is CLK, second is DIO
2. Brightness Range: 0 is dimmest, 7 is brightest, recommend 3-4 for indoor use
3. Display Digits: Standard module has 4 digits, display range -999~9999
4. Refresh Rate: No need for high-frequency refresh, 1-2 seconds update is sufficient
5. Colon Display: The colon between the middle two digits can be independently controlled, ideal for time display