Caleb

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Viewing 15 posts - 16 through 30 (of 63 total)
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  • in reply to: Position & Velocity data #886

    Caleb
    Moderator

    The UM7 only provides position and velocity data if an external GPS module is attached.

  • in reply to: UM7 calibration #885

    Caleb
    Moderator

    A basic overview of how we do calibration can be found here: http://www.chrobotics.com/library/sensors-for-estimation We don’t currently have an app note to describe methods of determining calibration coefficients.

  • in reply to: UM-7 magnetic calibration for land vehicles #872

    Caleb
    Moderator

    No, calibration requires that rotation is performed about all three axes during calibration.

  • in reply to: Units Confusion #868

    Caleb
    Moderator

    Hi Jason,

    The processed accelerometer data on the UM7 is reported in gravities. You should expect to see some slight errors based on accelerometer bias and scale factor error on the UM7, since it isn’t calibrated.

  • in reply to: Matlab Communication #864

    Caleb
    Moderator

    Sure, the Euler Angle data begins in register 112 (0x70). You can find that information in the datasheet, here: http://www.chrobotics.com/docs/UM7_Datasheet.pdf

  • in reply to: how do i use sat` information? #849

    Caleb
    Moderator

    I presume that you’ve connected a GPS module to your UM7? The UM7 won’t transmit satellite information unless an external GPS module is connected, and that GPS module must be transmitting NMEA GSV packets. Verify that your GPS module is connected properly and sending correctly formatted GSV packets.

  • in reply to: how do i use sat` information? #847

    Caleb
    Moderator

    Once bit 4 in the COM_SETTINGS register is set, you don’t need to transmit anything to read satellite information from the UM7 – it will transmit satellite information on its own. All you have to do is watch for the data to arrive.

  • in reply to: how do i use sat` information? #844

    Caleb
    Moderator

    The UM7 does transmit that information if bit 4 in the CREG_COM_SETTINGS register is set. Details about what is contained in the satellite status registers can be found in the datasheet here: http://www.chrobotics.com/docs/UM7_Datasheet.pdf

    The Serial Interface doesn’t currently watch for those registers or make data plots available for them. To extract the data, you’d need to either log the raw data from the sensor and then parse it, or write a parser that reads the data in real-time as it is sent by the sensor.

  • in reply to: Matlab Communication #842

    Caleb
    Moderator

    The Matlab script that can be downloaded from the site is a snippet designed to illustrate how to use serial port callbacks to read and parse data for the UM7, from within Matlab. You can delete the references to got_temperature_data and got_gyro_data.

    Basically, the serial callback function reads bytes in from the serial port and parses them. When a packet is received, you can check the packet type and address bytes to see if it is the data that you are interested in. If it is, you can log it, or set a flag (like got_temperature_data), or whatever you want to do with it.

  • in reply to: NMEA packets disabled #841

    Caleb
    Moderator

    The Serial Interface doesn’t read the NMEA packets. To see the NMEA data, you can open the serial port in a terminal like Putty.

  • in reply to: timeout error #837

    Caleb
    Moderator

    Yep. After you change the baud rate, you have to reconnect at the new baud rate.

  • in reply to: scaling um6 datas #835

    Caleb
    Moderator

    What are you using to read and parse the data? There are two possibilities: either the accel data is being interpreted incorrectly as you are reading it from the packet, or the proper scale factor isn’t being applied. Check out the datasheet for more details: http://www.chrobotics.com/docs/UM6_datasheet.pdf

  • in reply to: firmware update #830

    Caleb
    Moderator

    There is a pinout diagram on page 12 of the UM7 datasheet, available here: http://www.chrobotics.com/docs/UM7_Datasheet.pdf

    Connect the pin labeled BT0 to the pin labeled 3.3V, on the bottom-right connector shown in the diagram.

  • in reply to: UM6-LT SPI Troubles #827

    Caleb
    Moderator

    Hi Eugene,

    The SPI pins on the UM7 are not 5V tolerant, and operating above their absolute maximum rating could damage them (See page 10 of the datasheet, here: http://www.chrobotics.com/docs/UM7_Datasheet.pdf). The pins do have built-in ESD protection, so they may be OK. But it’s possible that the protection circuitry was burnt out, since they aren’t designed to handle sustained overvoltage conditions.

    Also, make sure that the timing constraints described in the datasheet aren’t being violated. To wit,

    “The maximum SPI clock rate is 10 MHz. However the UM7 needs at least 5 microseconds between bytes to copy the next byte into the SPI transmit register. For high clock rates, this means that a delay must be added between consecutive bytes for correct operation”

  • in reply to: firmware update #823

    Caleb
    Moderator

    To update the firmware, use the following steps:

    1) Download the newest firmware HEX file from here: http://www.chrobotics.com/shop/um7-orientation-sensor
    2) Make sure you have the latest version of the Serial Interface, available here: http://www.chrobotics.com/serial-interface
    3) Connect the BOOT pin on the UM7 to the 3.3V pin before applying power.
    4) Power up you UM7. The LED should *not turn on. This means that the bootloader started in programming mode.
    5) Make sure that your UM7 is appropriately connected to your computer. The USB Expansion Board is a good way to do so.
    6) Open the Serial Interface and select the correct COM port. Do NOT click “Connect.” Select the firmware HEX file you downloaded in step 1 and click “Program.” It should flash the new firmware. Once it finishes, disconnect the BOOT pin and cycle power. You are finished!

Viewing 15 posts - 16 through 30 (of 63 total)