Matt

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  • @kustra You have the general process down. You will want to perform step 4 before step 3, disabling sensor fusion will drop the internal state and will not be guaranteed give the correct results. Step 6 can be done at any time, and you will…
  • @gjin, the data rate is driven by an oscillator internal to the accelerometer and meets +/-1%. There may be a slight additional error or offset introduced when synchronizing the time base of the sensor with that of the smartphone. Is the result repe…
  • Hi @zacdy, We generally recommend using thermistors because a thermocouple generally requires a precision amplifier. There is firmware built in support for NXRT15XH103FA1B, otherwise you can use the ADC for raw voltage to use any thermistor yo…
  • MMRUser, If you look at the raw x-y data from your sensor in motion, it is producing perfect sine waves 90 degrees out of phase. This is the expected result. The basic yaw calculation is incorrect because there is both an x and y zero offset. Th…
  • @goamberg If you have a chance, I would highly recommend trying to calibrate a sensor or pair of sensors before a logging session. The calibration has the most effect on the magnetometer data, and calibration is automatic within sensor fusion. If …
  • Hello Leonard, None of the MMR series devices are specified to work without the battery connected. The only officially supported configuration includes the battery. This applies to all firmware versions. The issue is that the battery charge m…
  • @ebadier Thanks for your comments. We are looking at adding either a dedicated stop command, allowing repeated calls to refresh the timer, or accepting 0ms duration as a parameter to turn off an active output. All of which would be able to meet yo…
  • Hi fryjs, The MetaMotion devices run the library version of bosch sensorfusion from the BNO055. AXIS_MAP_CONFIG is, unfortunately, not a native feature of the library. It could be possible to add axis remapping to the native sensor outputs in…
  • Hi Blake, You're right, the MS5803 interface is a bit unconventional. The write (command) sequence is identical, except that they are interpreting the register address as a command. If you pass the command byte into mbl_mw_i2c_write as the re…
  • @lyubente, there is no voltage regulator on MetaMotionC, the battery directly supplies 3V. The radio SoC has a built in DC/DC converter for energy efficiency.
  • Hello Abdel, The maximum continuous discharge rate for the battery is 1C, which translates to about 110 mA. Higher current draw is not recommended due to self heating. The battery protection (PCM) circuit will cut off the battery around 2 to 5 …
  • That's great! We'll take a look at how we can clarify the documentation.
  • Hi Daryl, The I2C transactions look correct for the address byte. One key thing about I2C is that the address is only 7 bits, and the 8th bit is the R/Wb bit. Because the command was a write command the 8th bit is 0, which is why it seems lik…
  • Hi @Manos. Is that the complete wiring diagram? If so, you should attach the ground from the power source to one of the MetaWear ground connections as well. You can route the wire from the ground connection at the pressure sensor -- this is pre…
  • @MichaelG Thank you for reporting your findings. Idle current consumption is specified at nominal operating conditions (25C). This is standard for electronic component specification. We will update the data sheet to be more clear. My 30-50% co…
  • Piezo elements generate very high voltages when subject to mechanical impulses -- as much as several kilo volts. A high voltage spike like this on a pin will definitely reset a MetaWearC, if it does not destroy the pin circuitry, the chip or both.…
  • I wanted to note this as well from the SK6812 datasheet, this is the only spec they have for brightness: Could the doubled green intensity be working as expected?  Do you have a reference point for how "pure white" should look -- presumably usi…
  • @jdlombardo Lets focus on fast mode because slow is invalid for these new type pixel strands. Regarding fast mode and reduced brightness, this should imply that the "1" code is an issue for the pixels to receive. In your "pure white" test,…
  • @jdlombardo That is odd.  RG r0.5 could not generate as precise of signal for the fast mode due to its clock rate, though it would have been in spec to its original target (fast mode ws2811).  The slight change in timings on the SK6812 may have ma…
  • @jdlombardo Those neopixels should be used on fast mode (800kHz).  It looks like the latest driver chips do not have a slow mode at all anymore, so their normal is always our "fast". Our timings were based on WS2811 slow and fast modes.  Fast …
  • @MichaelG There is a firmware release in final testing that resolves the idle current issue. Root cause was silicon errata on the SoC, where the timer used to generate PWM signals does not correctly shut off when it is stopped.  The new firmwa…
  • @JanWeber Could you confirm that the drift in this data sample is in the pitch data and not the yaw data? These is not any obvious change in data when the drift begins.  It is very clear that the noise is 3-4x+ higher in magnitude than any vis…
  • @StefaanAvonds We have discussed possibly adding an encryption interface in the future that may behave similarly, but it is not under development or on our present roadmap. Something we can possibly do in the near term is add a "Connected" eve…
  • @rajmishra You can attach that between a GPIO and the 3V or regulated 3V pin, but you will need to add a series resistor to limit current.  GPIOs should not exceed 5mA. You can use the GPIO module as well as the timer module to create a simple…
  • @BenO If your board is consuming more power than idle mode, you are not in sleep mode.  Double check you firmware versions.  Verify with a second device.  Double check your measurement setup. Sleep mode is nearly equivalent in function to idle…
  • @JanWeber NDoF and IMUplus use the same settings for Accelerometer and Gyroscope, so there should be no noise difference in the raw data between these modes. I still suspect noise as the primary cause.  If it is, the solution would be increase…
  • @JanWeber Is there any chance you have a data set that shows the transition from correct pitch output to the incorrect output?  The last data set shows a nice transition from incorrect to correct output but not the other way. Of note in that d…
  • @BenO @MichaelG We were able to reproduce increased current consumption under a high intensity light source.  Shining a very bright light -- iPhone Flash LED at <1cm -- directly on the edge of the magnetometer chip scale package increased the c…
  • @StefaanAvonds This is not directly supported in the present firmware release (1.3.4). What kind of behavior would you expect if the pin cannot be provided?
  • @JanWeber Does the test bicycle have a steel frame?  This would probably have to be true for it to be interfering with the magnetometer. I have been studying the point of interest in your short data set. Of note is the large change in yaw,…