On 25 April 2016 at 12:31, florian.feldbauer85 via BeagleBoard <[email protected]> wrote: > Hey all, > > I did some further tests. > Actually none of the screens from my scope looks like I would expect it... > > Picture 1 shows the result, if I try to read something on the bus with a 14s > timeout (nothing was sended on the bus...) > Pic1 > Picture 2 shows the same, but this time there were messages send over the > bus. After 49 bytes, the beagle bone toggles the DE/!RE gpio to high for > unknown reasons (the test program is still reading from the UART interface) > Pic2 > Picture 3 shows the test, where the BeagleBone is sending > Pic3 > and finally picture 4 shows a test, where the BeagleBone should read > (timeout 3s) on the bus, then send something and again reading (with 3s > timeout)... > Pic4 > As you see, DE/!RS stays high after sending, although it should be low... > > In addition I would expect this line to be low when the port is not used, > but it's high.. > > I checked if there is any other process (or driver) accessing GPIO3_19 but I > could not find any... > > Any help is very much appreciated!
Any chance you could post a picture of a simple drawing of how you connected the 485 driver to the BB (like which pin to which pin and any extra components)? Also could you post your small C test program? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAKkGsYLNbX29uXkxnVM3cR-QP0h9rE%2BfxgB5fBy%3DbLUrh7sX3Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
