Description
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 the 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, lightning-proof amp; 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)
Specification
- 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
1.SC16IS752 UART expansion chip
2.ADUM1412 digital isolator
3.PC817 optocoupler
4.SP3485 RS485 transceiver
5.B0505LS power supply isolation module
6.RT9193-33 power chip
7.SMAJ12CA transient suppress diode array
8.Auto-recovery fuse
9.Status indicator
PWR: power indicator
RXD/TXD: UART transceiving indicator
10.Raspberry Pi GPIO connector: for connecting Raspberry Pi
11.RS485 terminal
12.MCU control header: for connecting host control boards like Arduino
13.120Î terminal resistor switch
14.Interrupt pin switch
15.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
Part List
- 2-CH RS485 HAT x1
- 2x20PIN female pinheader x1
- RPi screws pack (2pcs) x1