Hi, We are developing a complex embedded instument. It will consist of a tiny XScale board running linux attached via I2C to a variety of custom sensors and actuators that we intend to custom design. To efficiently utilize limited I2C bus bandwidth, I had intended to have the Linux system act as an I2C slave, responding to events detected by the intelligent sensors more or less in real-time. The alternative would be to poll each sensor continuously :-( I'm concerned about the following in i2c.h: /* Some adapter types (i.e. PCF 8584 based ones) may support slave behaviuor. * This is not tested/implemented yet and will change in the future. */ extern int i2c_slave_send(struct i2c_client *,char*,int); extern int i2c_slave_recv(struct i2c_client *,char*,int); Even if I implement these functions for the XScale's built-in I2C hardware how would an application detect incoming messages? I don't see any sort of event notification mechanism. Would i2c_slave_recv simply block until it received a message from the addressed client? If so, would I need to start multiple threads to monitor multiple clients simutaneously? Given this interface, the best I can think of right now is to define a sort of wildcard address so one thread could i2c_slave_revc from it and unblock when a message is received from any master. But, as you probably can tell, I'm pretty confused right now. I'm hoping one of the I2C package developers can set me straight... Regards, -- Brent Roman Software Engineer Tel: 831 775 1808 mailto:brent at mbari.org http://www.mbari.org/~brent
