MultiSerial Shield

From Hackstrich
Revision as of 17:14, 10 January 2010 by SarahEmm (talk | contribs) (Adding project status.)
MultiSerial Shield
MultiSerial Shield.png
This Page
Function: Provide two RS232 ports with 3.3v or RS232 levels, accessible via I2C.
Key Chips: NXP SC16IS752
External Ports: 2x RS232 (3.3v or RS232 levels), 10x GPIO
Required Pins: A4 (I2C SDA), A5 (I2C SCL)
Optional Pins: None

Project Status

PCB design complete, prototype PCBs ordered from BatchPCB. Parts still need to be ordered from Digikey.

Overview

The Arduino MultiSerial shield will let the Arduino access two RS232 serial ports via I2C. It will have switchable 3.3v or RS232 levels. This project exists mainly as a debugging tool for networks of BlinkieBits, as (at least during BlinkieNet design/prototyping) it would be extremely useful to be able to receive debugging information from a whole network of BlinkieBits, rather than just one at a time.

  • The NXP SC16IS752 chip is used, which gives 2 channels for ~$7. It needs 3.3v I/O and talks 3.3v RS232, so level shifters are needed. The I2C level shifter is a PCA9306 ($0.95 qty. 1), and the RS232 level shifter is a second-sourced TI MAX3232 in a SOT16 package ($1.70 qty. 1).
MultiSerial Shield Rev. 1 Schematic