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  • brtaylor's Avatar
    Yesterday, 04:09 PM
    Quick issue I see is that you're over running your buffer. You declare val to be 8 ints in size, but you're trying to stuff 9 ints in there! You need to declare val to be size 9: int val;
    2 replies | 31 view(s)
  • brtaylor's Avatar
    10-12-2018, 02:29 PM
    That looks great, I assume temperature was pretty constant?
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-12-2018, 12:00 AM
    Cool! Thanks Mike!!
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-11-2018, 11:56 PM
    Another updated schematic is attached and routes have been traced. Also attached is a render of the updated board design. Includes: the MK66FX1M0, the MKL02 programmer, the 16MHz and 32.768 kHz crystals, and a...
    27 replies | 8809 view(s)
  • brtaylor's Avatar
    10-09-2018, 08:37 PM
    Updated schematic attached. I changed the inboard through holes to 1.27 mm spacing, 2 rows with 15 positions per row. This is a more common and cheaper header to purchase; I added a ground to the extra pin on each. I...
    27 replies | 8809 view(s)
  • brtaylor's Avatar
    10-09-2018, 06:31 AM
    Correct, I'm not planning on including the programmer on board, I doubt it would fit without moving to BGA. The MKL04 is pretty wide pitched and should be possible to hand solder or reflow onto your carrier board. ...
    27 replies | 8809 view(s)
  • brtaylor's Avatar
    10-08-2018, 11:21 PM
    All, I'm designing a Teensy 3.6 "Pro" to enable access to all of the Teensy 3.6 pins and provide better packaging for placement directly in a final product. This is a project that I'm doing, but I'd like to make it...
    27 replies | 8809 view(s)
  • brtaylor's Avatar
    10-08-2018, 03:46 PM
    I haven't actually done this test yet, but I have a bunch of sensors sitting around, so I should probably design an experiment and try it out. Assuming all the potential sensors meet the requirements (i.e. necessary...
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-06-2018, 02:31 PM
    Hi Mike, do you mean in terms of sensors to test or tests to perform on potential replacement sensors? Thanks, Brian
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-06-2018, 02:22 PM
    Awesome, thanks!
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-05-2018, 03:07 PM
    It's definitely possible to get faster than 1ms tick resolution, the issue is that FreeRTOS expects to use systick and Arduino uses systick for delay. Changing systick so FreeRTOS has a tick faster than 1ms breaks the...
    7 replies | 212 view(s)
  • brtaylor's Avatar
    10-05-2018, 05:40 AM
    I had some discussion regarding RTOS on this thread: https://forum.pjrc.com/threads/53662-Teensy-4-RTOS I compile for Teensy 3.6 using a makefile on linux platforms. Greiman's port of FreeRTOS and Chibi both work as...
    7 replies | 212 view(s)
  • brtaylor's Avatar
    10-02-2018, 10:39 PM
    Thanks, but I'm meaning the HMMC 5883 from Honeywell.
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-02-2018, 01:03 PM
    After reading the data sheet on the BNO085, I'm less enthusiastic about it. Seems like an interesting concept with data rates of 400 Hz and acting as a sensor hub (you communicate with the Cortex M0 onboard, which is...
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-02-2018, 12:30 AM
    It's very disappointing. I was sad to see that they're still using a separate, poorly matched magnetometer. I noticed the SPI speed drop, but not the VDDIO change. I'm not sure if I'll bother with the ICM-20948; I've...
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    10-01-2018, 10:20 PM
    FYI, it looks like the MPU-9250 IMU will have its last shipment from Invensense in February of 2019. This probably won't mean much in the short term - Digikey is currently reporting 60k units in stock and I'm sure...
    213 replies | 53244 view(s)
  • brtaylor's Avatar
    09-27-2018, 09:54 PM
    As a software update for RAPTRS, instead of breaking from the v1.x software, I've merged the v1.x software into the RAPTRS repo and am pulling it through updates to v2.x. It's a bit messier and was a hassle to get the...
    13 replies | 518 view(s)
  • brtaylor's Avatar
    09-27-2018, 09:52 PM
    Hi Mike, great news! Looks like I'll update the hardware to v1.6 for the Raven nodes now that yours is tested working well. BTW, how do you like the BNO055? Does it have good library support? Good performance and...
    13 replies | 518 view(s)
  • brtaylor's Avatar
    09-22-2018, 01:09 AM
    This does seem fine with the FPU: https://github.com/vanbergeijk/teensy-3.6-FreeRTOS-template
    15 replies | 739 view(s)
  • brtaylor's Avatar
    09-21-2018, 07:05 PM
    I'm a little wary of ChibiOS because of its licensing structure. I develop open source, but would like my work to be able to be used in closed source projects.
    15 replies | 739 view(s)
  • brtaylor's Avatar
    09-21-2018, 06:58 PM
    Hi Mike, I saw Bill discussing an update to FreeRTOS v9, but it hasn't happened yet on his GitHub and the version posted (FreeRTOS v8) doesn't work. I haven't tried this yet, but that might be next up for me:...
    15 replies | 739 view(s)
  • brtaylor's Avatar
    09-21-2018, 06:17 PM
    Quick update: I tried Bill Greiman's port of FreeRTOS and, without support or an update, it's basically unusable for Teensy 3.5 / 3.6: https://github.com/greiman/FreeRTOS-Arduino Setting ticks faster than 1ms seems...
    15 replies | 739 view(s)
  • brtaylor's Avatar
    09-21-2018, 05:24 PM
    Is it possible to set a thread priority using this library, such that a higher priority thread will preempt a lower priority thread?
    378 replies | 65195 view(s)
  • brtaylor's Avatar
    09-16-2018, 03:31 PM
    0x75 is the register address, 0x71 is the expected value. For any register on the MPU-9250, except for the few listed, sending 0x00 will reset it to it's default value. The WHO_AM_I register is read only, so no point...
    26 replies | 525 view(s)
  • brtaylor's Avatar
    09-16-2018, 03:29 PM
    You don't really need to understand the FIFO, it holds 512 bytes of data, if I remember correctly, and is accessible through three registers (0x72 and 0x73 give you the count of how much data is in the FIFO and 0x74...
    26 replies | 525 view(s)
  • brtaylor's Avatar
    09-15-2018, 09:25 PM
    Look through the begin method in the MPU9250 class. You likely are not using the FIFO, but are instructing the MPU9250 to gather 7 bytes of data from the magnetometers at the sample rate (likely 100 Hz):...
    26 replies | 525 view(s)
  • brtaylor's Avatar
    09-15-2018, 07:07 PM
    The files in src, the other files are API documentation, API examples, and sensor documentation.
    26 replies | 525 view(s)
  • brtaylor's Avatar
    09-15-2018, 04:17 PM
    I'm biased, but I think my MPU-9250 library is pretty good: https://github.com/bolderflight/MPU9250 Once you can get the WHOAMI from the MPU-9250, look at the begin method of my library. It's pretty well commented,...
    26 replies | 525 view(s)
  • brtaylor's Avatar
    09-09-2018, 08:16 PM
    Likewise...my use case is a research quality flight control system for fixed wing and multi-rotor drones. I have some tasks that need to be executed regularly on an interrupt (data acquisition synced to an MPU-9250 data...
    15 replies | 739 view(s)
  • brtaylor's Avatar
    09-08-2018, 04:51 PM
    Hi Mike, thanks! The 3.5 and 3.6 will still work. Attached are a few photos of the SBUS backpack with a Teensy 3.2 and 3.6 with a servo connected. There's still enough clearance for everything. I was considering the...
    5 replies | 552 view(s)
  • brtaylor's Avatar
    09-08-2018, 03:24 PM
    Hi all, I'm excited to announce that my startup is launching a new product line, Teensy Backpacks! Arduino has shields, Feather has wings, Raspberry Pi has hats, BeagleBone Black has capes, and now Teensy has...
    5 replies | 552 view(s)
  • brtaylor's Avatar
    09-05-2018, 11:40 PM
    I did a simple test of multi-threading using two sensors, a MPU-9250 IMU on Wire and a BME-280 environment sensor on Wire1. First, this is the code without multi-threading. For me, using a Teensy 3.6 at 180 MHz, it...
    378 replies | 65195 view(s)
  • brtaylor's Avatar
    09-05-2018, 10:16 PM
    Thanks! It looks interesting, I would just hate to go that route and end up having to port everything to a different RTOS or TeensyThreads / EventResponder. Especially since it seems like the port to v9 hasn't been...
    15 replies | 739 view(s)
  • brtaylor's Avatar
    09-05-2018, 06:47 PM
    Paul, in this Teensy 4 post you suggested that, while not necessary, Teensy API's would move towards working with an RTOS. Any thoughts on which RTOS you're considering for Teensy 4? I understand that the selection of...
    15 replies | 739 view(s)
  • brtaylor's Avatar
    08-31-2018, 04:12 PM
    brtaylor replied to a thread uNav AHRS in General Discussion
    Yep! Then you'll want to do the same with +/- Y and +/- Z.
    907 replies | 109061 view(s)
  • brtaylor's Avatar
    08-31-2018, 03:06 PM
    brtaylor replied to a thread uNav AHRS in General Discussion
    For the accelerometer calibration, you'll need to align each axis (+/-X, Y, Z) with gravity, not magnetic north.
    907 replies | 109061 view(s)
  • brtaylor's Avatar
    08-22-2018, 11:42 PM
    Fun, long day integrating flight computers and making cabling for a very complete flight computer order going to NASA Armstrong Flight Research Center. We're replacing an older University of Minnesota research system...
    2 replies | 1010 view(s)
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