On Fri, 20 May 2016 11:11:39 -0400, you wrote: >The RX and TX at the beaglebone are working just fine. The TX output from >the RS-232 is 5V. Also i tried with and without connecting the red >wire(5V) from the RS 232. The necessary connections are GND (black wire) , >RX and TX(green and white wires) of the PL2303 USB to Serial adapter. >I also tried using a BeagleBone Black RS-232 Serial Micro-cape (see >http://www.logicsupply.com/cbb-ttl-232/). > >Note: RX and TX are working just fine for all the UART ports.(i confirm >after every try)
Even though you check after each try, putting a signal over 3.3 volts on the BBB pins (or 1.8 volts on the analog pins) is just asking for trouble. Good engineering says not to put too much voltage on processor pins. 5 volts on a 3.3 volt maximum pin is too much. You may or may not have overstressed the pins, which may or may not fail sooner or later. If you are in college, and you have not been told this, then you need to speak to your professors. Data sheet maximum ratings are not suggestions. You need the ground and the RXD and TXD lines. The maximum voltage on the RXD and TXD lines should be 3.3 volts, on the average adaptor, there's a jumper for that. There's also a jumper to select a 5 volt swing. You do not need either the 3.3 volt power line or the 5 volt power line. Harvey > >On Fri, May 20, 2016 at 10:32 AM, evilwulfie <[email protected]> wrote: > >> if he connected it to the cnc with no 3.3v adapter it also could have >> fried the bbb. >> >> >> >> >> >> On 5/20/2016 7:08 AM, Wally Bkg wrote: >> >> >> You do realize that on your PC the RS232 signal levels from the COM ports >> are +/- 12V while without extra hardware the Beaglebone levels are 0-3.3V? >> You may have fried the RX input on the Beaglebone if you've connected it >> directly to a +/- 12V RS232 TX output. >> >> Assuming you've got the logic levels right, If you used a "standard" >> serial cable on your PC to the CNC machine it probably activated the CTS or >> DTR automatically, you may need to run one more wire from the Beaglebone, >> or tie it active on the CNC interface side. >> >> >> On Friday, May 20, 2016 at 7:36:15 AM UTC-5, Shaurabh Kumar Singh wrote: >>> >>> The cnc is dte as far as I know. >>> And I am assuming since it worked without hardware handshaking on my pc, >>> it shouldn require the same for the bbb either. >>> That said, I have tried both the settings. With and without hardware >>> handshaking. >>> The only thing I can think of is for some reason perhaps, the default >>> serial port settings must be different on the bbb (with debian) than my pc >>> (where I previously successfully had communicated-windows) >>> On 20 May 2016 08:19, "Wally Bkg" <[email protected]> wrote: >>> >>>> On Thursday, May 19, 2016 at 7:08:55 PM UTC-5, Shaurabh Kumar Singh >>>> wrote: >>>> >>>>> Okay. I shall look it up. >>>>> By the way, i did confirm the working of the UART pins(UART1 RX to >>>>> UART4 TX and vice versa). >>>>> I had two terminal tabs open and when i typed into one and >>>>> entered(UART1 settings) it showed up on the other terminal with UART4 >>>>> settings. I inferred that the Adafruit libraries work just fine for the >>>>> BBB >>>>> (correct me if i am mistaken) >>>>> >>>>> It is just that while interacting with a CNC machine(with a HAAS OS) it >>>>> is not communicating rather just showing up what is being sent. >>>>> >>>> >>>> You may need CTS or DTR active for the other end to accept data and >>>> respond. Are you sure the CNC machine doesn't need a "hardware >>>> handshaking" protocol? >>>> >>>> If you have uart1 talking to uart4 on the Beaglebone, that says the >>>> problem is the physical connection and/or the protocol to the CNC machine. >>>> Is the CNC machine wired to be DTE or DCE? >>>> >>>> At this point I think you need help from the CNC machine's >>>> documentation, or from someone familiar with that particular machine. >>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "BeagleBoard" group. >>>> To unsubscribe from this topic, visit >>>> <https://groups.google.com/d/topic/beagleboard/Z1s_NwXYNrw/unsubscribe> >>>> https://groups.google.com/d/topic/beagleboard/Z1s_NwXYNrw/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> To view this discussion on the web visit >>>> <https://groups.google.com/d/msgid/beagleboard/3b9db8f5-b454-4801-b4a5-49a867c0e255%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> https://groups.google.com/d/ >>>> msgid/beagleboard/3b9db8f5-b454-4801-b4a5-49a867c0e255% >>>> 40googlegroups.com. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> -- >> 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/30ad5a80-4c6b-453b-b74b-c63f010996c4%40googlegroups.com?utm_medium=email&utm_source=footer> >> https://groups.google.com/d/msgid/beagleboard/30ad5a80-4c6b-453b-b74b-c63f010996c4%40googlegroups.com >> . >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/Z1s_NwXYNrw/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/0eb51074-b51a-f658-f69c-10a7ec8aa58b%40gmail.com >> <https://groups.google.com/d/msgid/beagleboard/0eb51074-b51a-f658-f69c-10a7ec8aa58b%40gmail.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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