At risk of asking the obvious, have you double checked you're putting out serial data? Your datasheet requires the BW pin to be floating or low to output out serial data, otherwise it puts out pulse data on the same pin.
Before you try the inverter approach, maybe just put a multimeter on the Tx pin on the device - it should be high (ie 3.3V) most of the time. If it's transmitting once per second, NMEA0183-style, even then the voltage should be closer to 3.3V than GND. If it's closer to GND, then you'll need to invert it. I'm working with a whole stack of NMEA0183 devices and assuming they're properly functioning, the only thing you can really get wrong are baud rate, inverted signal, wrong pin (tx instead of rx, in which case you hear nothing) or software config error. For software, I just use screen - "screen /dev/ttyO2 9600" - rather than minicom or any of the other scripts. Much easier. On 5 November 2013 09:52, Gustavo Oliveira <[email protected]>wrote: > I guess I did some mistake answering back there =P > It is in UART_RX. > > I search the internet and found that maybe I'm getting the inverted > messages, all the 1s as 0s and the 0s as 1s. > > > On 5 November 2013 09:50, Gustavo Oliveira <[email protected]>wrote: > >> 1) I'm using the 3.3V pin, so the voltage is acceptable in p9_22. >> >> 2) What do you mean by setttings, the fields when I export the pin? Or >> the pin mode? I think mine are ok, what should they be? >> >> 3) I tried many applications, python scripts, c scripts, minicom... >> >> >> On 5 November 2013 05:26, Maxim Podbereznyy <[email protected]> wrote: >> >>> 1) I would place a voltage translator or a simple voltage divider based >>> on two resistors to reduce 5 volts to the acceptable 3.3V. >>> >>> 2) check the pinmux settings for that pin >>> >>> 3) what terminal application do you use to read data? Check the serial >>> port parameters and don't forget to disable the hardware flow control if any >>> 05 нояб. 2013 г. 3:55 пользователь "Gustavo Oliveira" < >>> [email protected]> написал: >>> >>>> Hi, thank you for quick reply, >>>> I'm using a BeagleBone and Ubuntu 12.04. >>>> >>>> I have the TX connected to p9_22, which is uart2 RX. >>>> >>>> On Monday, November 4, 2013 7:38:06 PM UTC, lisarden wrote: >>>>> >>>>> hi! >>>>> >>>>> what board do you use and what OS? >>>>> >>>>> your datasheet says that VCC is +5V and the TX pin also work in 0-VCC >>>>> range. If you use beaglebone it accepts only 3.3V, however there can be >>>>> options >>>>> >>>>> >>>>> 2013/11/4 Gustavo Oliveira <[email protected]> >>>>> >>>>>> Hello, >>>>>> I'm trying to read from a LV-Maxsonar-EZ0 using the serial interface. >>>>>> >>>>>> I have connected the wires correctly and I have placed an overlay in >>>>>> uart2. >>>>>> The problem is the data I'm reading from the sensor. I can only get >>>>>> garbage, but its not completely wrong because the data changes according >>>>>> to >>>>>> the distance to obstacle. >>>>>> >>>>>> The datasheet for the sensor can be found here: >>>>>> datasheet<http://www.maxbotix.com/documents/MB1000_Datasheet.pdf> >>>>>> . >>>>>> >>>>>> I searched google for a day and couldn't find anything... >>>>>> Someone posted in a raspberry pi forum that the problem is the >>>>>> meaning of 1s and 0s, but I changed active_low to 1 and I got the same. >>>>>> >>>>>> I'm not very proficient with electronics, so I might take some time >>>>>> following instructions. >>>>>> Nonetheless all the help will be welcome. >>>>>> >>>>>> -- >>>>>> 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/groups/opt_out. >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> LinkedIn - http://www.linkedin.com/in/maximpodbereznyy >>>>> Company - http://www.linkedin.com/company/mentorel >>>>> Facebook - https://www.facebook.com/mentorel.company >>>>> >>>> -- >>>> 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/groups/opt_out. >>>> >>> -- >>> 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/gOK8R4_mRzw/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >> >> > -- > 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/groups/opt_out. > -- 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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