Rob French (KC4UPR)
Hello, I have one of the 20x4 LCD displays on my uBITX, with the I2C backup to free up pins. I removed the two pull-up resistors from the (5V) backup, so that I could use it in conjunction with the SI5351.
Question... so I can't recall which pull-up is now getting used to pull the I2C lines up to 3.3V, but I'm wondering, can I add another I2C device to this bus, without adding any other conversions?
Specifically, I would like to use I2C to communicate between the Raduino and a Teensy 3.2 that I'm using for DSP audio filtering. I was going to use serial, but I decided it was too much of a pain to try to interrupt the CAT stream, so I figured I'd try I2C instead. But I want to make sure I can actually add the Teensy to the mix.