May 27, 2009 #1 E EDA_hg81 Advanced Member level 2 Joined Nov 25, 2005 Messages 507 Helped 2 Reputation 4 Reaction score 2 Trophy points 1,298 Activity points 4,808 I used the scope to check, the data and clock are toggling. Only have glitch during acknowledge time when scl is low. The writing protect pin is connected to ground. What are the possible reasons? Thanks.
I used the scope to check, the data and clock are toggling. Only have glitch during acknowledge time when scl is low. The writing protect pin is connected to ground. What are the possible reasons? Thanks.
May 28, 2009 #2 tkbits Full Member level 5 Joined Dec 4, 2004 Messages 242 Helped 39 Reputation 78 Reaction score 2 Trophy points 1,298 Activity points 2,209 Time. The write time is much slower than read time. Completing the I²C transfer only starts the write cycle. Some chips will not acknowledge while they are in the write cycle, you can repeatedly attempt a zero-length write until you get an acknowledge. Or you can simply wait some arbitrarily large amount of time, for example 10 ms, before attempting to read the written data.
Time. The write time is much slower than read time. Completing the I²C transfer only starts the write cycle. Some chips will not acknowledge while they are in the write cycle, you can repeatedly attempt a zero-length write until you get an acknowledge. Or you can simply wait some arbitrarily large amount of time, for example 10 ms, before attempting to read the written data.
May 29, 2009 #3 E EDA_hg81 Advanced Member level 2 Joined Nov 25, 2005 Messages 507 Helped 2 Reputation 4 Reaction score 2 Trophy points 1,298 Activity points 4,808 yes. you are right. I didn't wait long enough for writing. Take care and best regards.