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Altera_Forum's avatar
Altera_Forum
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12 years ago

Getting data from a rtc device through I2C

Hi all, I would like to retrieve information from a RTC device which is directly connected to a GPIO, using the i2c protocol. So, the first step was to load the i2c-gpio driver with this piece ...
Altera_Forum's avatar
Altera_Forum
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12 years ago

I'm coming back after a while ;-)

So I eventually succeed in detecting my i2c device (RTC) despite I still get some half-amplitude i2c signals. Actually it was not a software issue but rather a FPGA configuration problem. To explain it simple:

https://www.alteraforum.com/forum/attachment.php?attachmentid=7811

On figure 1, you can see that we used intermediate signals between the GPIO and the SDA and SCL hardware pins to adapt the 2-bit-wide bus. However it seems that it was not a proper solution because when by-passing these signals I could be able to scan successfully the rtc, using the i2cdetect utility.

But, as I described below, I still get some weird i2c frames... Anyway, I can now get data from my rtc device so my problem is solved!

Thanks to both of you ;-)