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keymuu
- 10th December 2008, 01:26
Hello!

I'm using picbasicpro 2.50b and having 2.2kohm pull-ups on SCL and SDA. I'm able to use the i2c for reading and writing an external eeprom. However, I'm not able to read with I2CREAD Epson (Toyocom) RX8025 RTC. Can see with the oscilloscope (on SCL and SDA) that the RTC is running but I2CREAD throws the control to the label (error label). I can't understand why this is not working:
I2CDevice = $65 ' =read device
I2CAddress=$04: I2CREAD sda,scl,I2CDevice,I2CAddress,[second],error
As said, no problems with i2c eeprom, but rtc read jumps direclty to "error".
And no problems to write it, but reading....

Have you used Epson RX8025?
Hoping somebody could give some hints what is going on... Thank you :)

wayne2056
- 16th December 2008, 14:35
I saw this posted on another sight. Perhaps a clue?

By chance, has anyone interfaced the Epson RX8025 by I2C to any LPC
chip? Or any MPU for that matter? The standard read method for I2C
works very reliably for this chip, but there is a 'simplified read' in
the datasheet which requires fewer steps. I have not been able to get
this method work very well at all. The chip never sees a STOP and
therefore hangs quite often. Perhaps there is a bug in the chip for
this method and Epson and their FAEs have been no help at all.