Re: TXT and I2C bus speed
Verfasst: 22 Jul 2019, 14:30
Hi Rei,
I also did approach fischertechnik about this issue.
However I am very surprised that this is still an issue. I was out of the practical I2C work because of more important things in live for almost 3 years.
And the discussion about I2C issues like: "a signal output as power supply " give me the idea that the TXT I2C bus was already operating very well.
What me wonder the most is that the FT-community I2C-boys did not notice these kind of elementary problems.
What I also notice is the importance of the right total of Rp's in relation with the total of capacity of the I2C connection lines+ devices.
(See also: viewtopic.php?f=21&t=5376 )
After reading the I2C articles in the FT-pedia's about I2C, I don't understand why these basic issues where not mention.
The NXP specification and user manual is very clear and good readable about this all.
A good reason to repeat the link: https://www.nxp.com/docs/en/user-guide/UM10204.pdf
I was lucky that the 100kHz device PCF8574(A) is able to handle the 400kHz bus speed and that I have I nice logic analyse (LabNation SmartScoop).
But I also can imagine that a normal end-user who rely on the RoboPro I2C 100Khz elements, will not understand why a real 100kHz device is not working properly.
Cordialement
I also did approach fischertechnik about this issue.
However I am very surprised that this is still an issue. I was out of the practical I2C work because of more important things in live for almost 3 years.
And the discussion about I2C issues like: "a signal output as power supply " give me the idea that the TXT I2C bus was already operating very well.
What me wonder the most is that the FT-community I2C-boys did not notice these kind of elementary problems.
What I also notice is the importance of the right total of Rp's in relation with the total of capacity of the I2C connection lines+ devices.
(See also: viewtopic.php?f=21&t=5376 )
After reading the I2C articles in the FT-pedia's about I2C, I don't understand why these basic issues where not mention.
The NXP specification and user manual is very clear and good readable about this all.
A good reason to repeat the link: https://www.nxp.com/docs/en/user-guide/UM10204.pdf
I was lucky that the 100kHz device PCF8574(A) is able to handle the 400kHz bus speed and that I have I nice logic analyse (LabNation SmartScoop).
But I also can imagine that a normal end-user who rely on the RoboPro I2C 100Khz elements, will not understand why a real 100kHz device is not working properly.
Cordialement