On July 7, 2008 11:41:05 am Daniel Berenguer wrote: > I'm trying to send/receive messages via RS485 using a simple MAX485 IC > connected to a Netarm processor (Digi Connect-ME). The problem is that I > need to enable/disable the transmit option through the UART RTS line but > RTS remains high after the transmission, causing the RS485 slaves to not to > respond to the master's query.
I manually hacked the serial driver on mcf5282 (m68knommu) to turn on RTS automatic negation (a feature on that particular UART) -- you could check for a similar feature on your target. My patch was just a hack, ideally it should be turned on through an IOCTL. Failing that, you could set up a short timer to expire when the last character is supposed to be sent out and negate RTS after that (that was my first idea before discovering the RTS autonegate feature in hardware) but you may run into long delays if the kernel timer granularity is too low. -A. _______________________________________________ uClinux-dev mailing list [email protected] http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by [email protected] To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
