From: Cristian Mitu <[email protected]> Reply-To: "[email protected]" <[email protected]> Date: Tuesday, August 19, 2014 at 7:23 AM To: "[email protected]" <[email protected]> Subject: Re: [beagleboard] UART RS485 transciever setup
> Hello John, > > Sorry to bother you but i have a question regarding the input output features > of the TXS0104 that you recommended me a while back. The problem is that i am > doing some calculations for the decoupling network of the power regulator. And > usually in this calculation i would determine voltage noise margins by seeing > the input/output min and max voltage characteristics of the communicating > ICs. Firstly i am not sure about the characteristics off the BeagleBone Black > but looking at the processor datasheet i see a 2.85 min output high and a 0.45 > max output low(correct me if i am wrong). Now according to the TXS0104 > datasheet the min high input should be 2.9 and the max low input should be > 0.15. These numbers seem too high and do not allow for any noise margin. I > just want to know if i am reading the datasheet wrong somewhere because > usually there is a noise margin even if just a little. All you need is a 0.1uF ceramic decoupling capacitor on both power rails (3v3 and 5v). Everything else will work just fine. Regards, John > > Sorry again for the bother but i really need to know if I am doing this right. > > Regards, > Cristian > > > 2014-07-03 21:41 GMT+02:00 John Syn <[email protected]>: >> >> From: Cristian Mitu <[email protected]> >> Reply-To: "[email protected]" <[email protected]> >> Date: Thursday, July 3, 2014 at 12:22 PM >> To: "[email protected]" <[email protected]> >> >> Subject: Re: [beagleboard] UART RS485 transciever setup >> >>> Thank you again Jhon you are a life saver this part looks perfect for what i >>> need. I think i will use two, one for the RX and TX signals seeing as it >>> doesn't need direction input and one for the DE and RE enable signals. Thank >>> you again >> Then use the TXS0104 >> >> Regards, >> John >>> >>> >>> PS >>> Also thank you Jerônimo for your suggestion. >>> >>> >>> 2014-07-03 20:53 GMT+02:00 John Syn <[email protected]>: >>>> >>>> From: Jerônimo Lopes <[email protected]> >>>> Reply-To: "[email protected]" <[email protected]> >>>> Date: Thursday, July 3, 2014 at 5:31 AM >>>> To: "[email protected]" <[email protected]> >>>> Subject: Re: [beagleboard] UART RS485 transciever setup >>>> >>>>> Cristian, >>>>> >>>>> >>>>> 2014-07-03 8:55 GMT-03:00 Cristian Mitu <[email protected]>: >>>>>> Thank you for your response John. >>>>>> So i only need to to translate when sending data to the BBB or for >>>>>> both TX and RX ? >>>>>> >>>>> >>>>> I'm using BBB with a 75176 transceiver (5V powered). Put a diode between >>>>> BBB Rx and 75176: >>>>> >>>>> 75176------|<|------BBB Rx >>>>> >>>>> And a pullup resistor, from BBB Rx to 3.3V. >>>>> >>>>> It's working fine. >>>> Only for slow data speeds. >>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> 2014-07-03 5:18 GMT+02:00 John Syn <[email protected]>: >>>>>>> >>>>>>> From: Cristian Mitu <[email protected]> >>>>>>> Reply-To: "[email protected]" <[email protected]> >>>>>>> Date: Wednesday, July 2, 2014 at 1:49 PM >>>>>>> To: "[email protected]" <[email protected]> >>>>>>> Subject: [beagleboard] UART RS485 transciever setup >>>>>>> >>>>>>> Hello guys, >>>>>>> >>>>>>> >>>>>>> I am designing a board ( an adapter board for the BeagleBine black) that >>>>>>> is un upgrade for a current system. Beacuse of this i specifically have >>>>>>> to link a 5V TTL RS485 transceiver to one of the UARTs available. I am >>>>>>> not sure what logic family the BeagleBone uses(though i'm guessing that >>>>>>> it is CMOS) and because of this i want to know if this old transceiver >>>>>>> can be wired directly to the BeagleBone or is it unavoidable that i have >>>>>>> to use logic level translators for the signals. I apologize for the >>>>>>> newbie question and i thank you in advance for your response. >>>>>>> You will need to translate the 5V TTL signals to 3.3V before connecting >>>>>>> to the BBB. >>>>>>> >>>>>>> Regards, >>>>>>> John >>>>>>> >>>>>>> >>>>>>> PS >>>>>>> >>>>>>> If you could direct me to some good drivers for RS485 communication i >>>>>>> would be overwhelmed with joy and eternally grateful :) >>>>>>> >>>>>>> -- >>>>>>> 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]. >>>>>>> >>>>>>> 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/tsrW0hBClBc/unsubscribe. >>>>>>> To unsubscribe from this group and all its topics, send an email to >>>>>>> [email protected]. >>>>>>> >>>>>>> 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]. >>>>>> 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]. >>>>> 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/tsrW0hBClBc/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> 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]. >>> 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/tsrW0hBClBc/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> 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]. > 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]. For more options, visit https://groups.google.com/d/optout.
