Pull-up resistors on i2c bus. Enough is enough?
Posted 22 September 2011 - 06:27 AM
Q1: I added a 24LC256 EEPROM to the bus, along with the other two devices. I *didn't* add pull-up resistors along with the EEPROM because I'm assuming that SDA and SCL are already pulled-up by the resistors on the first two breakouts. Am I right?
Q2: If one were to keep adding breakout boards on an i2c bus, and each breakout board had its own pull-ups, that would amount to resistors in parallel so that the overall effect would be less resistance than the smallest of the individual resistors, right? I imagine this would eventually become a problem...
I just found this interesting web page that investigates the effects of different pull-up resistors on i2c signals. I guess that if I'm really concerned about how it's all playing out, I better buy an oscilloscope and do my own similar analysis. Always wanted an excuse to buy one but not sure I'd use it often enough to justify the cost.
Posted 22 September 2011 - 06:44 AM
-- H.L. Mencken, "What I Believe"
Posted 22 September 2011 - 07:18 AM
Posted 25 November 2013 - 03:12 PM
I'm a beginner in Netduino and I've bought myself the microcontroller and the BMP085 ( amongst other things)
I have no experience regarding the wiring of I2C board. Can someone help me get on my way?
I've bought this version, so no pull up resistors are required if I understood correctly.
You can follow my progress on http://netduinoblog.wordpress.com.
Thanks in advance,
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