- Mon Dec 21, 2015 6:12 am
#36885
Hi cwilt, what threw me off on the pullups is I was using 4.7k on the uMite setup and it worked just fine. As a matter of fact, on ALL the circuits I have ever built using i2c, that is the only value I have ever used, even with other micros, and never had an issue. Here is a good article that I found while pulling my hair out. Once I got the unit to respond, I could see on the LA what the code was doing.
http://dsscircuits.com/articles/effects ... -resistors
So it did not occur to me that this could be a problem, especially at a 100khz speed. To make the display work with the esp, I had already tried different values from 1.5k to 10K, but my code was not correct when I was doing this, so kind of a catch 22 situation, and also finally got a LA on my bench, which by the way was pretty cheap ($9.00).
Anyway, I wound up using 2.7k and that worked. Now I will make a habit of checking the signals with a scope and not assuming. I am just happy it works and I learned a lot while trying.
http://dsscircuits.com/articles/effects ... -resistors
So it did not occur to me that this could be a problem, especially at a 100khz speed. To make the display work with the esp, I had already tried different values from 1.5k to 10K, but my code was not correct when I was doing this, so kind of a catch 22 situation, and also finally got a LA on my bench, which by the way was pretty cheap ($9.00).
Anyway, I wound up using 2.7k and that worked. Now I will make a habit of checking the signals with a scope and not assuming. I am just happy it works and I learned a lot while trying.
