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Rs 232 – How it works

The RS-232 Transceiver Breakout Board by Soldered enables seamless communication between devices using the RS-232 protocol. It leverages the MAX232E integrated circuit, which converts RS-232 voltage levels (±3V to ±15V) to TTL/CMOS logic levels (0V to 5V) and vice versa. This ensures compatibility between modern microcontrollers and legacy RS-232 devices.

howitworks
MAX232E Dual RS-232 Driver and Receiver With IEC61000-4-2 Protection

How it works​

The RS-232 Transceiver Breakout Board acts like a translator for your devices. It takes the high-voltage signals used in RS-232 communication (±3V to ±15V) and converts them into the low-voltage signals (0V to 5V) that modern microcontrollers and logic devices understand—and it works the other way around, which is all made possible due to the MAX232E chip onboard that handles all the heavy lifting.

Main points:

  • The charge pump circuit inside the MAX232E generates the higher voltages needed for RS-232 communication from a simple 5V power supply.
  • It has two channels for sending data (DIN1/DIN2 to DOUT1/DOUT2) and two for receiving data (RIN1/RIN2 to ROUT1/ROUT2), so you can send and receive at the same time (full-duplex communication).
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Plus, it’s built with ESD protection, so it won’t fry if there’s static electricity or electrical noise.

Enable and Disable​

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Device is powered when the VCC pin is connected to a 5V power source.

The MAX232E operates as long as a stable 5V supply is provided. When unpowered, it can safely remain connected to active RS-232 devices without causing damage, thanks to its internal safeguards.

How to Connect It?​

  • Connect Power:

    • Attach the 5V pin to your power source (4.5V - 5.5V range).
    • Connect the GND pin to the ground of both your microcontroller and RS-232 device.

  • Wiring the Signals:

    • Connect the DIN1/DIN2 pins to the TTL/CMOS data outputs of your microcontroller.
    • Connect the ROUT1/ROUT2 pins to the TTL/CMOS data inputs of your microcontroller.
    • Attach the RIN1/RIN2 pins to the RS-232 data outputs of your external device.
    • Attach the DOUT1/DOUT2 pins to the RS-232 data inputs of your external device.

This breakout board is ideal for interfacing modern microcontrollers with legacy or industrial systems requiring RS-232 communication, such as modems, barcode scanners, or industrial equipment.