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- I2C pullup resistor calculations 2 answers
I'm connecting a PIC18F46K22 (master) to a PIC18F4620 (slave) using I2C. The wire between the devices is ~30cm. I'm using 400kHz without slew rate control. Later on, I'll add another 18F4620 on ~5cm from the master (~35cm from the other slave).
How do I calculate the pull-up resistance needed on both the SCL as the SDA line?
Does it matter where I place the pull-up (near the master, near the slave, both, in the middle, ...)?