If you contact MaxBotix or check the specs on the Pololu page
http://www.pololu.com/product/723/ you can see it has the following outputs
- Three interfaces (all are active simultaneously):
- Serial output: asynchronous, logic-level, *inverted*, 9600 bps 8N1
- Analog output: (Vcc/512) / inch (10 mV/inch when input voltage Vcc
= 5 V)
- Pulse width output: 147 μs/inch
On Tue, Nov 5, 2013 at 9:37 AM, Mike Bremford <m...@bfo.com> wrote:
> 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 <gustavo.pinho...@gmail.com>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 <gustavo.pinho...@gmail.com>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 <lisar...@gmail.com> 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" <
>>>> gustavo.pinho...@gmail.com> 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 <gustavo....@gmail.com>
>>>>>>
>>>>>>> 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
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>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> LinkedIn - http://www.linkedin.com/in/maximpodbereznyy
>>>>>> Company - http://www.linkedin.com/company/mentorel
>>>>>> Facebook - https://www.facebook.com/mentorel.company
>>>>>>
>>>>> --
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>>>
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