--- In [email protected], "gazoox22" <[EMAIL PROTECTED]> wrote: > > Now, I tested the rewrite of the i2c kernel mode driver from > http://www.gevawebsolutions.com/wiki/index.php?title=FB_General_Issues > The sample code is worth to try. But with the PCF8591 I can set the > A/D converter, measured with a voltmeter. The D/A conversion doesn't > work. Testet with and without pull up resistor. Sometimes the value > differs from 0x00. What could be the problem? I can't visual the > lines, because no osciloscope. >
Hi, First off, thanks for using the driver. Next, I don't understand you're not able to do the AD conversion. I'm doing it without any problems (device is actually running now next to me without giving one bit of a problem). The example code I wrote should give you the opportunity to do both AD as well as DA. You're sure you have connected all the pins in a correct way? This is my "construction": Pin 1: to tap of potmeter Pin 2: open Pin 3: open Pin 4: open Pin 5: gnd Pin 6: gnd Pin 7: gnd Pin 8: gnd Pin 9: 100 ohm (series!) to SDA line of I2C bus Pin 10: 100 ohm (series!) to SCL line of I2C bus Pin 11: open Pin 12: open Pin 13: gnd Pin 14: +Vcc Pin 15: open Pin 16: +Vcc Next to this, the other pins of the potmeter are connected to gnd and +Vcc (3.3V). There's also a pull-up resistor of 5k6 to +Vcc on each I2C line. Best rgds, --Geert
