Description
Overview
This is a 2-channel isolated RS485 expansion HAT designed for Raspberry Pi, adopts the SC16IS752+SP3485 solution, with embedded protection circuits such as power supply isolation, ADI magnetical isolation, and TVS diode, etc.
It is easy to control the 2-channel RS485 for auto transceiving via SPI interface. Due to its fast communication, stability, reliability, and safety, it is an ideal choice for fields like industrial automation.
Features
- Standard Raspberry Pi 40PIN GPIO extension header, supports Raspberry Pi series boards
- Adopts SC16IS752+SP3485 dual chip combination, converts SPI to RS485, data rate up to 921600bps
- Allows transceiving data manually or automatically, configured by DIP switch
- Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic
- Onboard auto-recovery fuse and protection diodes, ensures the current/voltage stable outputs, provides over-current/over-voltage proof, improves shock resistance
- Onboard LEDs for indicating the power and transceiver status
- Breakout SPI control pins, for connecting with host control boards like Arduino
- Comes with development resources and manual (examples in C and Python)
Specifications
- UART expansion chip: SC16IS752
- RS485 transceiver: SP3485
- Communication interface: SPI
- Data rate: 300 ~ 921600 bps
- Operating voltage: 3.3V / 5V
- Dimensions: 65mm × 56.5mm
- Mounting hole size: 3.0mm
What’s on Board
- SC16IS752 UART expansion chip
- ADUM1412 digital isolator
- PC817 optocoupler
- SP3485 RS485 transceiver
- B0505LS power supply isolation module
- RT9193-33 power chip
- SMAJ12CA transient suppress diode array
- Auto-recovery fuse
- Status indicator
PWR: power indicator
RXD/TXD: UART transceiving indicator - Raspberry Pi GPIO connector: for connecting Raspberry Pi
- RS485 terminal
- MCU control header: for connecting host control boards like Arduino
- 120Ω terminal resistor switch
- Interrupt pin switch
- Operating mode selection
Half-auto: A=0, B=1
Full-auto: A=1, B=0
Example
Pinouts
| PIN | RASPBERRY PI (BCM) | DESCRIPTION |
|---|---|---|
| VCC | 5V | 3.3V/5V power supply |
| GND | GND | Ground |
| SCK | P21 (SPI1 SCLK) | SPI clock input |
| MOSI | P20 (SPI1 MOSI) | SPI data input |
| MISO | P19 (SPI1 MISO) | SPI data output |
| CS | P18 (SPI1 CS) | SPI chip select |
| IRQ | P24 | Interrupt output |
| EN1 | P27 | Channel 1 TX/RX enable: high for TX, low for RX |
| EN2 | P22 | Channel 2 TX/RX enable: high for TX, low for RX |
Dimension
Reviews
There are no reviews yet.