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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

Hi everyone,

As I cannot found my rtc device on the i2c bus, I am using an oscilloscope to see what's happening on the bus. Here are the measures performed on the SDA and SCL pins:

https://www.alteraforum.com/forum/attachment.php?attachmentid=7752

We can see that we get a NAK from the device. But something catch my attention: the time the clock is high between the first SCL's rising edge and the following falling edge. Is it normal?

Remember that my rtc device address is 0x68