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TIDA-00484: RS-485 replacing with Sub-1GHz connection

Part Number: TIDA-00484
Other Parts Discussed in Thread: CC1310, TIDC-01002, CC1150, CC1020

Hello,
I want to replace RS-485 connection with wireless one and to increase a distance.

Now up to 10 temperature sensors are connected to PC with RS-485 as daisy chain.
These sensors are placed across the line of sight and send results on PC request.
In a new project I want to avoid the cable connection and increase a distance up to 2-3 km between the PC and the last sensor in the chain (possibly up to 16km distance would be needed in future).

The PC should collect results in real time every 1-2 seconds (the sensor's result consists of 3 bytes).
Delays in the results receiving are not permitted, my application should get them directly - not from a cloud or some server.
(Or if the delay is a few seconds, it should be known and stable - but this is worse).

Is it possible to use TIDA-00484 as node and may be CC1310 wireless MCU LaunchPad™ development kit, connected to PC, to provide wireless connection on 2km distance and to get data with minimal delay (<1s)?

If this technology is not correspond to a project, whould You advice me another ST technology?

Best regards,
Vadim

  • Hello,

    This is very possible with the TI Design you are talking about. On the PC side you can use a CC1310 flashed with our collector example, this will receive the data from this sensor board (without having to modify code) and you should be able to see this temperature in a terminal window.

    As far as connecting 10+ sensors and receiving and diplaying info in your PC, you can do it also and what I would recommend is having a task in charge of UART connection with the PC and sending this data periodically. As far as the interval of sending data, this can be modified on the config.h file inside the project.

    I would also recommend our TIDC-01002, sensor to cloud example. This example is great since it will display all the information you need on a web based GUI. No internet required (minimum a WIFi router to connect to).

    Regards,
    AB
  • Hello,

    Thank You very much for the answer.

    The aim of my project is to get data only on PC's request (through CC1310) addressed to particular node (TIDA-00484) and to direct the data to our Application

    and to design our software, using Your API and examples as a base.

    May You answer to next questions?

    1) should the pair of devices (the TIDA-00484 and CC1310 flashed with Your collector example) provide connection on 20 km distance with direct sight (not urban location)?

    If not,  which distance is really achievable in direct sight?

    2) ir PC through CC1310 requests the data from TIDA-00484, may You assess a delay between request and received by CC1310 correct answer, providing the distance is maximal?

    I didn't  find an information about transmitting-receivign process, so, I don't understand, how this pair would behave, when the transmission fails - may be, it tries to reconnect in different frequency range, while the correct answer is not received? how much time it may require in the worst case? when it stops?

    or may be  transmission is accomplished only one time without check for correctness?

    3) I find also different TI's Sub 1GHz transceivers/ (CC1020/21, CC1111, CC1150 and so on).

    Is the pair TIDA-00484 + CC1310 better for my task and why? May be, due to specific software for error correction?

    Best regards,

    Vadim

  • Hello Vadim

    1. Sub 1 GHz technology will allow you to potentially achieve this, but using our LAUNCHPADS you will not get this type of range. Expect around a couple Km range with line of sight in anon urban environment and using our LRM(Long Range Mode) which is part of our example codes and smartRF settings. To get that range an amplifier and better antenna will be needed. See the following documentation as it will help you in calculating the actual range:

    e2e.ti.com/.../375823
    www.ti.com/.../swra479


    2. You can discard UART_READ/UART_WRITE latency as this is so fast is negligible. If you are using TI 15.4 Stack, then the time will depend on the type of configuration you are running (Beacon, non Beacon, or Frequency Hopping) but is modifiable in the Config.h (Polling interval).

    3. For these other transceiver you will need to create your protocol as these are proprietary RF communication, they will not work out of the box with the configuration you want to run. I believe the configuration you want to run will be better as the code is out and read to be used and will work no modification or minor modification.

    Regards,
    AB
  • Hello,
    thank You very much for Your answers
    and usefull link to report 'Achieving Optimum Radio Range'.

    The Excel file I saw earlier, but TI's advertisement: 'that spans full-buildings to city-wide coverage for over 20 km on a coin cell battery' raised the questions.

    On the 2nd question:
    May You nevertherless assess delay time between start and end of transmission? Let it be a case, when the pair (transmitter-receiver) works close to their limit (the maximal distance for fixed Tx power, Rx sensitivity, antenna parameters, external EMI and 3 bytes of payload data).
    Hundreds of milliseconds, second, few seconds?
    I think about a time stamp in data, but it requires a periodical clock synchronization for each node, using some wired interface (4km walk).

    Best regards,
    Vadim
  • Hello,

    I would say a couple hundred milliseconds.

    Regards,
    AB