Hi Andreas, On Mon, 13 Oct 2008 03:20:48 +0200, Andreas Seidler wrote: > I want to connect a MAX1236 (ADC) [1] to a I2C/SMBus in a > PC-Engines/ALIX board to monitor some voltages. > This board have a AMD geode CPU with an an I2C companion (scx200_acb.c). > > > Installed I2C busses: > > i2c-0 smbus CS5536 ACB0 > > [EMAIL PROTECTED]:/# i2cdetect -F 0 > > Functionalities implemented by /dev/i2c-0: > > I2C no > > SMBus Quick Command yes > > SMBus Send Byte yes > > SMBus Receive Byte yes > > SMBus Write Byte yes > > SMBus Read Byte yes > > SMBus Write Word yes > > SMBus Read Word yes > > SMBus Process Call no > > SMBus Block Write no > > SMBus Block Read no > > SMBus Block Process Call no > > SMBus PEC no > > I2C Block Write yes > > I2C Block Read yes > > [EMAIL PROTECTED]:/# i2cdetect -y 0 > > 0 1 2 3 4 5 6 7 8 9 a b c d e f > > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- > > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > 40: -- -- -- -- -- -- -- -- -- -- -- -- 4c -- -- -- > > 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > > 70: -- -- -- -- -- -- -- -- > > but i cant access the MAX1236 on slave address 0x34. > (0x4c is the onbard LM90)
Maybe it's not wired properly? If it is wired properly, then another possibility is that the MAX1236 is doing clock stretching beyond what the CS5536 supports... > Does "I2C no" means the CS5536 is a plain smbus without i2c support? Yes and no. It means that the scx200_acb driver runs the CS5536 in SMBus mode without plain I2C support. But there is also the scx200_i2c driver (which I would love to see go away in favor of i2c-gpio but that's another story) which can use the same pins as GPIO to do plain I2C. If I read the MAX1236 datasheet properly, it uses transactions which aren't part of the SMBus set, so you may need to use the scx200_i2c driver, depending on what exactly you need to do with the MAX1236. There are still a few SMBus transactions which should work though, and that may be enough. -- Jean Delvare _______________________________________________ i2c mailing list [email protected] http://lists.lm-sensors.org/mailman/listinfo/i2c
