SparkFun
SparkFun USB to RS-485 Converter
This is the newest revision and fixes issues with the last board. This breakout board pairs an SP3485 RS-485 transceiver with an FT232RL USB UART IC to co...
The TXDEN pin of the FT232RL is connected to the transmit and receive enable inputs of the SP3485, this line is used to control the transmission mode of the RS-485 transceiver. With the proper drivers installed, the FT232RL will enumerate as a virtual COM port; the drivers are available for Windows, Mac and Linux.
This breakout board includes the SP3485, FT232, TX/RX/RTS LEDs, Mini-B USB connector, filter capacitors, and other components shown on the schematic. We’ve broken out the RS485 output to three different connections: (1) an RJ-45 connector, (2) a 3-pin 3.55mm screw terminal, and (3) a 3-pin 0.1" pitch header; none of these output connectors come populated.
Jargon buster
Plain-language definitions for the technical terms used above.
- breakout
- A breakout is a small circuit board that makes a tiny or hard-to-solder component easier to connect to with standard pins. It matters because this OLED module can be wired into a microcontroller project without needing to solder directly to the display’s fine contacts.
- COM port
- A COM port is the way many computers present a USB-connected serial device to software. It matters because it lets you configure or read the board from a computer using serial terminal tools or navigation software.
- RS485
- RS485 is a robust wired serial communication standard often used in factories, farms, and buildings where cables may be long or electrically noisy. It matters because it lets this controller connect to industrial sensors, meters, and control equipment over longer distances than typical hobby serial wiring.
- RTS
- RTS stands for Request To Send, a serial flow-control signal used to manage when a device is ready to receive data. It matters when moving fast serial streams because flow control can help prevent lost data.
- UART
- UART is a simple serial connection that sends data over separate transmit and receive wires, often labelled TX and RX. It matters because this module is designed to replace a wired UART cable with a wireless link while keeping the same serial data format.
Find this product in
SparkFun USB to RS-485 Converter Schematic
Schematic · 29.2 KB · Click any page to view full size
SP3485 Transceiver Datasheet
Datasheet · 125.4 KB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 591.4 KB · Click any page to view full size
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