UART-2-RS232 has two serial UART channels for RS232 and a hardware I2C bus for communications with a host microcontroller. It translates data from I2C to RS232 and adds more serial ports to the host microcontroller system.
If you install RS485 transceivers and 5.08mm-pitch screw terminals into the spaces provided, either or both of the channels can be configured (via jumpers) to use RS485 instead of RS232. Spaces are provided for installing terminating resistors and their selection jumpers as well. The photograph shows the board with one set of RS485 components installed, for illustration only. The recommended RS485 transceiver is the ST3485, operating at 3.3V.
The control pins and 5V power supply connections are available on a 20-pin (2×10) expansion connector for interfacing to existing microcontroller systems. This board can be connected either as a piggyback daughterboard on a microcontroller board (one with a matching connector) using standoffs or can be placed away from the microcontroller board using a 20-wire ribbon cable.
The expansion connector is plug-in compatible with MicroTRAK, MINI-MAX and BSCB systems. You can use it in your own system too, of course; see the manual for the expansion connector's pinout.
UART-to-RS232/RS485 Peripheral Board Features
- 2 peripheral RS232 channels (or 1 or 2 peripheral RS485 channels)
- 64 bytes of transmit and receive FIFO (SC16IS752 Dual UART IC)
- Slave mode 2-wire Serial Interface (I2C) for the host communications
- Footprints to install transceivers, terminating resistors and 2-pin terminal blocks for RS485
- Two 9-pin standard DB9 Male RS232 connectors
- Two additional 10-pin 0.1" dual-row headers for RS232 connections
- 20-pin Expansion connector for a host microcontroller board
- Up to four boards can be connected to the host microcontroller system
- Single operating voltage: 5V DC, 10mA typical (20mA maximum) current consumption
- On-board 3.3V DC regulator powered from the external 5V DC through the expansion connector
- Dimensions: 2.35 × 2.40 inches (5.97 × 6.10 cm)
- Mounting holes of 0.125 inches (3.5 mm) on the four corners
- 0° to 70° C operating, -40° to +85° C storage temperature range
If you want to daisy-chain multiple boards together, you can purchase cable and connectors separately to construct daisy-chain cables to suit your setup.
Optional Recommended Products for this Item