DEVMO CJMCU-9548 TCA9548A 1-to-8 I2C Multiplexer Breakout Board User Manual

1. Úvod

The DEVMO CJMCU-9548 TCA9548A is a 1-to-8 I2C multi-channel expansion multiplexer breakout board. This module addresses the common challenge of connecting multiple I2C devices that share the same fixed address to a single microcontroller. It allows for the expansion of a single I2C bus into eight independent I2C channels, enabling communication with up to eight identical I2C devices.

2. Klíčové vlastnosti

• Rozhraní: I2C IIC
• Čip: TCA9548A
• Selectable I2C Address: 0x70-0x77
• Pracovní svtage: 1.65 V - 5.5 V
• Max Clock Frequency: 400 kHz

3. Nastavení a instalace

This section outlines the steps for physically connecting and preparing your TCA9548A multiplexer for operation.

3.1 Konec komponentyview

The breakout board comes with the TCA9548A chip and requires soldering of header pins for breadboard compatibility or direct wiring.

Obrázek 1: Nahoře view of the TCA9548A breakout board with header pins. This image shows the main chip, I2C input pins (VIN, GND, SDA, SCL, RST, A0, A1, A2), and eight multiplexed I2C output channels (SC0/SD0 to SC7/SD7).

Obrázek 2: Spodní část view of the TCA9548A breakout board. This view shows the underside of the purple PCB, highlighting the clean layout and solder points for the header pins.

3.2 napájecí zdroj

The TCA9548A is compatible with both 3V and 5V logic levels. Connect the VIN pin to your microcontroller's power supply (e.g., 3.3V or 5V) and GND to the common ground.

3.3 I2C Connection

Connect your microcontroller's I2C SDA and SCL lines to the SDA and SCL pins on the multiplexer board. The multiplexer's default I2C address is 0x70. This address can be modified by adjusting the A0, A1, and A2 pins, allowing for up to eight multiplexers on a single bus (addresses 0x70 to 0x77).

• VIN: Power input (1.65V - 5.5V)
• GND: Země
• SDA: I2C Data Line (from microcontroller)
• SCL: I2C Clock Line (from microcontroller)
• první: Resetovat pin (aktivní nízká)
• A0, A1, A2: Address selection pins for the multiplexer itself.

Connect your I2C devices to the multiplexed output channels (SC0/SD0 through SC7/SD7). Each pair represents an independent I2C bus.

4. Návod k obsluze

To communicate with a specific I2C device connected to one of the multiplexer's channels, you must first select that channel. This is done by writing a single byte to the multiplexer's I2C address.

4.1 Výběr kanálu

The multiplexer's default I2C address is 0x70. To select a channel (e.g., channel 0), write the byte 0x01 to the multiplexer's address. For channel 1, write 0x02, for channel 2, write 0x04, and so on, up to channel 7, which corresponds to writing 0x80. Each bit in the byte corresponds to a channel, allowing you to enable one or more channels simultaneously (though typically only one is active at a time for devices with identical addresses).

• To select Channel 0: Write 0x01 to multiplexer address (e.g., 0x70)
• To select Channel 1: Write 0x02 to multiplexer address
• To select Channel 2: Write 0x04 to multiplexer address
• ...
• To select Channel 7: Write 0x80 to multiplexer address

After selecting a channel, all subsequent I2C communications from your microcontroller will be routed to the devices connected to that specific channel until a different channel is selected or the multiplexer is reset.

4.2 Přample Usage Scenario

If you have multiple temperature sensors, all with the same I2C address, you can connect each sensor to a different channel of the TCA9548A. To read from Sensor A (on Channel 0), you would:

1. Napsat 0x01 to the TCA9548A (address 0x70).
2. Perform an I2C read operation to Sensor A's address.
3. To read from Sensor B (on Channel 1), write 0x02 to the TCA9548A, then perform an I2C read to Sensor B's address.

4.3 Vizuální demonstrace

5. Specifikace

6. Údržba

The TCA9548A multiplexer board is a robust electronic component that requires minimal maintenance. To ensure longevity and reliable operation:

• Udržujte desku čistou a bez prachu a nečistot. V případě potřeby použijte měkký, suchý kartáč nebo stlačený vzduch.
• Nevystavujte desku extrémním teplotám nebo vlhkosti.
• Ujistěte se, že všechny spoje jsou bezpečné a bez koroze.
• Desku držte za okraje, abyste zabránili poškození součástí nebo statickému výboji.

7. Řešení problémů

If you encounter issues with your TCA9548A multiplexer, consider the following troubleshooting steps:

• No Communication with Multiplexer:
  • Verify power connections (VIN and GND) are correct and within the 1.65V-5.5V range.
  • Check I2C SDA and SCL connections from your microcontroller to the multiplexer.
  • Confirm the multiplexer's I2C address (default 0x70) and ensure it doesn't conflict with other devices on the main bus. Check A0, A1, A2 pin configurations if the address was changed.
  • Ensure pull-up resistors are correctly implemented on the main I2C bus if not already present on your microcontroller board.
• No Communication with Devices on Multiplexed Channels:
  • Ensure the correct channel is selected by writing the appropriate byte to the multiplexer's address.
  • Verify the I2C device's connections to the selected multiplexer channel (SCx/SDx).
  • Confirm the I2C address of the device connected to the multiplexed channel.
  • Check for proper pull-up resistors on the multiplexed channels if required by the connected device.
• Přerušovaná komunikace:
  • Check for loose connections or poor soldering.
  • Ensure adequate power supply stability.
  • Reduce I2C clock speed if operating over long wires or with many devices.

8. Informace o záruce

This DEVMO product is covered by a standard manufacturer's warranty against defects in materials and workmanship. Please refer to the product packaging or the official DEVMO webKonkrétní záruční podmínky naleznete na webových stránkách. Uschovejte si doklad o koupi pro případ reklamace.

9. Technická podpora

For technical assistance, detailed documentation, or further inquiries regarding the DEVMO CJMCU-9548 TCA9548A multiplexer, please visit the official DEVMO support website or contact their customer service. Contact information can typically be found on the product packaging or the manufacturer's webmísto.