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lamaPLC: TTL to RS485 Module
The onboard MAX485 chip is a low-power, slew rate-limited transceiver for RS-485 communication. It is connected to 5.08 mm pitch 2P binding posts, which makes RS-485 wiring convenient. All the chip's pins are exposed and can be controlled and operated by the microcontroller. It operates on a single 5V power supply with a rated current of 300μA.
MAX485 switching logic
MAX485 modul pinout
| RO | TTL side | Receiver output |
|---|---|---|
| RE | TTL side | Receiver output enable |
| DE | TTL side | Driver output enable |
| DI | TTL side | Drive input |
| Vcc | 5V power supply | |
| A | RS-485 side | The non-inverting input of the receiver and the non-inverting output of the driver |
| B | RS-485 side | Receiver inverting input and driver inverting output |
| GND | Ground | |