Archive of the former Yahoo!Groups mailing list: ComputerVoltageSources
Subject: I2C update
From: "djbrow54" <davebr@...>
Date: 2006-04-14
I've got my basic code verified that implements an I2C to serial
bridge. I'm going to use this to replace my SpeakJet interface in my
PSIM and move to an I2C implementation that uses the TTS256.
I've got the speech portion working to the TTS256. I've got to wait
for Ken to document the TTS256 so I know how to implement pass through
mode. This may be more of a challenge with all of the buffers and
queuing.
Here's what I have implemented so far:
ATMEGA8 28 pin DIP, internal RC oscillator
mode selectable for two baud rates
31250 with no flow control (e.g. a second MIDI output)
9600 baud with SpeakJet flow control
832 byte buffer
default I2C address of 48 hex (address byte=$90)
mode selectable for alternate I2C address
7 bit input to specify address
This is a one IC solution for interfacing to a SpeakJet through a
TTS256. I'll probably implement another mode for direct interface to a
SpeakJet without the TTS256 (it requires slightly different flow
control)
With the addition of 2 resistors this can be used as a second MIDI
output. I am using my PSIM to convert MIDI from my keyboard controller
to I2C messages which I send to the ATMEGA8 for conversion to MIDI to
drive my Ensoniq synthesizer.
I'm open to other feature suggestions for future expandability.
Dave