I have a device I built that is basically a keypad and a Parallax Serial LCD in an enclosure. It uses a Db25 connection to a main board with a Parallax SX28 master micro-controller and SX28 slave chips to control multiple 7 segment sets of 4 LED displays. However, the Parallax SX28 is now obsolete and I am trying to redesign this with the Arduino which I have not too much experience with but still keep learning.
So far I have found information online to control the 7 segment sets of 4 LED displays with a bootloaded 328P chip (or Arduino board) with not too much problem. So that covers the "slave" driver aspect.
Now as far the master goes, It needs to control the keypad and the LCD and send the data to one of the slave bootloaded 328P chips controlling the 7 segment sets of 4 LED displays. I have also found code that I have modified and is working with the Arduino. Since the Arduino (or 328P) doesn't have a ton of I/O, I have used a TI PCF8574N chip to take the 8 data lines from the keypad and convert them into I2C that the Arduino (or 328P) can understand. The Parallax Serial LCD only uses RX, Vcc, and Gnd so nothing was needed there. It works fine with the standard Arduino "Serial" commands.
I would like to first reduce the DB25 cable into a CAT5e cable which is certainly possible as the only lines I now have are: SDA, SCL, Vcc, Gnd and RX. The slave 328P chips and 7 segment sets of 4 LED displays are going to be run with ribbon cable to the master 328P on the main circuit board.
What I would really like to do is to have a wireless solution for the I2C Keypad and Serial LCD. But the Arduino only has 1 set of RX/TX unless I go with an Arduino Mega. Is there such as thing as wireless I2C or would I have to use a differnt chip to convert the keypad into Serial?
Any help would be greatly appreciated.
Thanks,
Tim Gilmore