Forum Rule: Always post complete source code & details to reproduce any issue!

Search:

Type: Posts; User: cmason

Page 1 of 2 1 2

Search: Search took 0.00 seconds.

  1. Note that this appears to be for the nRF8001...

    Note that this appears to be for the nRF8001 chips in particular a specific BLE shield. It's cool that they're officially supporting the Arduino community. However, it seems like there are already...
  2. Hi Alistair, Yeah, I've spent a significant...

    Hi Alistair,

    Yeah, I've spent a significant amount of time with the nRF51822 chips, albeit first with their dev kit and then with a custom board (which also includes EPaper display hardware). The...
  3. Replies
    87
    Views
    125,254

    Random question: if I only have one SD card slot...

    Random question: if I only have one SD card slot on the SPI bus, do I need to use a pin for Chip Select or can I simply ground it?
  4. Replies
    1
    Views
    2,378

    Understanding part of epaper display circuit

    I have the Adafruit e-paper display working with the teensy 3. I'm trying to make a board that has the example circuit for that epaper display. I'm trying to understand and perhaps simplify a...
  5. Thread: MIDI HID combo

    by cmason
    Replies
    14
    Views
    5,748

    I have this working on teensy 3 here...

    I have this working on teensy 3 here. Main program here. As Paul said, it's just a matter of editing code. :)

    -c
  6. Replies
    13
    Views
    16,293

    I re-read my comments above, and while I think...

    I re-read my comments above, and while I think they are all true, they're not very concretely helpful. I'd like to help, though.

    To that end, I've written a simple test program. The main guts...
  7. Replies
    13
    Views
    16,293

    I'm making pretty extensive use of stl and C++ in...

    I'm making pretty extensive use of stl and C++ in a project. I mostly create containers at startup at startup, use reserve() to preallocate, and try to avoid extending them beyond that allocated...
  8. Replies
    0
    Views
    1,319

    fixed point math library

    I'm looking for a good fixed point math library for some graphics stuff. Needs to have trig. Nice to have a C++ library with operator overloading. Nice to have something that's optimized for ARM.
    ...
  9. Replies
    57
    Views
    41,745

    I spent a bunch of time messing with the SPI unit...

    I spent a bunch of time messing with the SPI unit before finally getting it to work. I haven't tried to use it as a slave. Three things that helped me:

    Make sure you enable the clock to the SPI...
  10. Thread: Noob question

    by cmason
    Replies
    3
    Views
    1,350

    The teensy always runs the flashed program when...

    The teensy always runs the flashed program when it is started regardless of whether it is connected to USB. Is it possible that you're doing something which is requiring USB? You didn't say which...
  11. Replies
    3
    Views
    2,785

    Scott and I reflowed the chip and then spent some...

    Scott and I reflowed the chip and then spent some time with his scope. Without enabling the t3's internal pullups, with just 10k external resistors we were seeing some significant ramping on the sda...
  12. Replies
    3
    Views
    2,785

    Teensy 3 I2C to battery fuel gauge. Pullups.

    I'm trying to talk to this MAX17048 battery fuel gauge. I designed a board and soldered it using a hot plate. I fear I may have either not completely soldered it or may have fried the chip during...
  13. Replies
    19
    Views
    15,065

    Teensy 3 as AVR ISP programmer?

    Has anyone succeeded in using the emulated SPI code to run the AVR-ISP program in the arduino examples directory on a teensy 3?

    I'm trying to program a ATMEGA328P-PU and I'm getting the following:...
  14. I would love to see a bit better API for sysex. ...

    I would love to see a bit better API for sysex. It took a bit of effort to figure out the current one. In particular that the length was in usb_midi_msg_data1 and that this was an 8bit quantity and...
  15. Replies
    1
    Views
    1,533

    Control AC Mains voltages

    Sorry if this is a FAQ, but I'd like to control grounded AC mains devices with a teensy 3 (3.3V). Obviously I can just use a relay with a low enough coil current and a high enough rating. However,...
  16. I also have code to use the DMA to do this here:...

    I also have code to use the DMA to do this here:

    http://hg.cmason.com/teensy3/src/90cffffb1abe3da67810725a14924ef19349a405/teensy/main_sampler.cpp...
  17. Adafruit has a bunch of really useful tutorials...

    Adafruit has a bunch of really useful tutorials. They are not teensy-centered per se but they are pretty easily adapted. For instance: digital in, multiple button debounce, analog input.
  18. Replies
    4
    Views
    3,733

    I agree about HID versus Serial. Seems way easier...

    I agree about HID versus Serial. Seems way easier from a user perspective. There's a bunch of really nice libraries, for instance from node.

    I've been using JSON to encode the data. This is...
  19. You can just use the code I posted above: ...

    You can just use the code I posted above:



    *portConfigRegister(pin) = PORT_PCR_MUX(1) | PORT_PCR_PE;


    -c
  20. Dedicated LiPo battery charger chips

    I've been investigating making a battery charger/monitor board for the teensy3. I've been looking at dedicated chips for charging Lithium Polymer (LiPo) batteries, such as these very affordable bare...
  21. Have you checked out i2cdev...

    Have you checked out i2cdev?
  22. Replies
    263
    Views
    243,964

    I don't see any prices there, but these folks...

    I don't see any prices there, but these folks have 4-5m strips of 60 LEDs/m for ~$12 per meter, and strips of 30 LEDs/M for ~ $7/m:
    ...
  23. Replies
    263
    Views
    243,964

    So, can someone help double check my math here on...

    So, can someone help double check my math here on the timing for using SPI?

    This diagram (from here):

    145

    shows 1.25us cycle. I think what happens with these chips is that in the middle of...
  24. Replies
    263
    Views
    243,964

    I spent some time playing with these LEDs...

    I spent some time playing with these LEDs which have an integrated WS2811 controller. (Thanks to Ward Ramsdell from Dorkbot for spotting me a few of them to play with.)

    I could get it to light up...
  25. yes...

    yes, i have.
  26. Replies
    82
    Views
    42,891

    Recent raspbian distributions are set up to use...

    Recent raspbian distributions are set up to use hardware floating point. Some cortex m4 chips have an FPU, but not the one in the teensy. There are some (older?) raspberry distributions that have...
  27. So, this library...

    So, this library and the given code:


    Adafruit_SSD1331 display = Adafruit_SSD1331(1, 2, 3);

    compiles fine for me with the modifications described in the previous thread. I *think* the...
  28. Replies
    82
    Views
    42,891

    Btw, I have binutils, and am working on building...

    Btw, I have binutils, and am working on building gcc as debs for raspbian. It's not all that slow: maybe 3-4 hours for the gcc build. I'm using a Sandisk Ultra Class6 card.

    I spent a bunch of...
  29. Replies
    6
    Views
    4,628

    Paul, I tried a couple of my simple programs...

    Paul,

    I tried a couple of my simple programs and they work.

    Out of curiosity, are you using newlib or glibc or ...? I've been using newlib with gcc 4.8 but maybe there's downsides to that...
  30. Replies
    1
    Views
    2,057

    raw hid on linux

    Has anyone successfully used the hid_listen RAW hid serial console on linux? I'm trying to get it to work on a raspberry pi and hot having much luck. It works great on my mac.

    I've tried the...
  31. Replies
    82
    Views
    42,891

    Does the teensy_loader_cli source on the pjrc web...

    Does the teensy_loader_cli source on the pjrc web site work with teensy 3.0? It does not list the freescale chip as an option. It compiles fine on the raspberry and the teensy3 shows up in lsusb:
    ...
  32. Replies
    21
    Views
    14,441

    Success!

    After putting this aside for a while I finally came back to it and I have GCC 4.8.0 compiled on my mac and the resulting binaries working on the teensy3. The resulting GCC supports the following...
  33. Yeah, this had nothing to do with pull up or pull...

    Yeah, this had nothing to do with pull up or pull down. Just a stupid bug.

    For posterity: the teensy 3 does indeed have both internal pull up and pull down resistors. Both seem to work ok. ...
  34. Internal pull up and pull down resistors on teensy 3

    I'm simply trying to drive buttons off digital pins. I have the buttons wired to 3.3V through a 1k resistor and then each button leads to a different pin. I'm then trying to use the internal...
  35. Replies
    14
    Views
    15,972

    This is old, but for posterity: this thread...

    This is old, but for posterity: this thread has the code needed to read the mac address.
  36. Are you reflashing instead of just rebooting (ie...

    Are you reflashing instead of just rebooting (ie are you pushing the button on the board or just plugging and unplugging)? If yes this is a known issue: the eeprom is actually stored in flash and is...
  37. I'm basically thinking of something like this in...

    I'm basically thinking of something like this in pins_teensy.c:


    typedef void (*voidFuncPtr)(void);
    typedef void (*intFuncPtr)(int);
    volatile static voidFuncPtr intFunc[CORE_NUM_DIGITAL];...
  38. So I'm wondering about the same thing: How do I...

    So I'm wondering about the same thing: How do I monitor multiple pins and not have to write a separate function for each?

    I can think of two possibilities here:


    Modify attachInterrupt so...
  39. Nice, thanks for posting your code snippet! -c

    Nice, thanks for posting your code snippet!

    -c
  40. Replies
    21
    Views
    14,441

    I'm trying to basically follow (manually) the...

    I'm trying to basically follow (manually) the build script in the launchpad tree (common file; prereqs file). I configured gcc trunk with:


    ../gcc-trunk/configure --build=i686-apple-darwin10...
  41. Replies
    21
    Views
    14,441

    Compile GCC for teensy 3?

    If I wanted to compile a more recent gcc for the teensy 3 what configure options should I use? I'd like to otherwise get as close as possible to what's in Paul's distribution.

    Thanks,

    -c
  42. Replies
    7
    Views
    3,900

    This is not the behavior I see. I see that when...

    This is not the behavior I see. I see that when I plugin the teensy my code runs. I suspect something else is going on. Maybe some timing thing? Can you blink the LED or something to verify that...
  43. Replies
    3
    Views
    2,778

    I have DMA ADC working as Paul described using...

    I have DMA ADC working as Paul described using two DMA channels (one to read back the conversion result and the other to fire the next conversion). The code is still a bit rough, but there's lots of...
  44. Do you maybe mean GPIOC_PDDR = 1

    Do you maybe mean GPIOC_PDDR = 1 << 5;

    You perhaps know this, but the teensy3 directory will pretty much compile on its own without any of the "arduino stuff" save the compiler. I don't use the...
  45. Have you looked at the periodic interrupt timer...

    Have you looked at the periodic interrupt timer (PIT) section of the datasheet?

    -c
  46. Replies
    23
    Views
    17,080

    Wow. That's like > $200 in switch parts...

    Wow. That's like > $200 in switch parts if I understand you right. Really cool! Thanks Paul!

    -c
  47. The default teensy loader on that page has not...

    The default teensy loader on that page has not yet been updated for teensy 3. Use teensy loader >= 1.0.7. For example from here.
  48. 15. See usb_desc.c...

    15. See usb_desc.c usb_endpoint_config_table.
  49. Replies
    18
    Views
    18,532

    The interrupt controller on the teensy 3 is a...

    The interrupt controller on the teensy 3 is a "nested" interrupt controller which basically means that you can assign configurable priority to interrupts. Only interrupts with a higher priority than...
  50. Replies
    14
    Views
    23,980

    By default the teensy acts like a USB serial...

    By default the teensy acts like a USB serial device. If you want to use pin 1/2, try using HardwareSerial or Serial1.

    -c
Results 1 to 50 of 75
Page 1 of 2 1 2