Step 7: Uploading firmware

If you are using a kit from our Tindie store which included ItsyBitsy M4 MCU, you can skip this step - the MCU comes already pre-programmed.

Using precomplied binaries (M4 only)

The easiest way to program the controller is by using pre-built binaries (for Itsy Bitsy M4 only).

  1. Download the latest release of the project from github repository. Extract the downloaded archive to some place on your computer, and navigate to directory code/binaries/ItsyBitsyM4.

  2. Connect the controller assembly to your computer using a micro USB cable. If you are doing it for the first time, you might get a message about installing drivers; in this case, wait until it tells you that your hardware is ready to use. Double-click the reset button on ItsyBitsy; your ItsyBitsy should appear as an external drive on your computer, with a name like ITSYM4BOOT. Open that drive in your file browser window; inside you should see files CURRENT.UF2, INDEX.HTM, and UF2_INFO.TXT.

  3. First, you need to format the flash storage on ItsyBitsy board as FAT filesystem; you only need to do that once. To do that, inside extracted directory code/binaries/ItsyBitsyM4, find the file formatter.UF2 and drag and drop it to ITSYM4BOOT. If you get a question “do you want to copy this file without its properties”, click “Yes”. After that, the ItsyBitsy will reboot, ITSYM4BOOT will disappear from your computer, and the formatter script will run; you won’t see any visible output.

  4. Double-click the reset button on ItsyBitsy again; ITSYM4BOOT drive should again appear on your computer. This time, drag povstaff-vX.X.UF2 file to it. Again, the ItsyBitsy will reboot. The microcontroller now contains the povstaff software.

  5. Press Reset button once (or disconnect and reconnect the USB cable) to restart the ItsyBitsy. It should now appear as an external drive with the name POVSTAFF in your computer, which should be empty. Find in the extracted archive folder images and drag and drop files rg-lines.bmp and imagelist.txt to POVSTAFF. Eject the POVSTAFF drive and disconnect the USB cable; it is now ready for use.

Building from source

An alternative way to program the controller is by building the software from source. You will need Arduino IDE 1.8 or later to do that. It is assumed that you have some experience with Arduino, e.g. know how to install libraries using library manager.

  1. Start Arduino IDE and install the board support files for your Itsy Bitsy (see instructions for M4, nRF52840).

  2. Make sure that you have the following libraries installed. All of them can be installed using library manager:

    • FastLED

    • Adafruit_TinyUSB

    • Adafruit_SPIFlash

    • Sd_Fat (adafruit fork)

    • Adafruit_Sensor

    • Adafruit_MPU6050

    • POV-library

  3. Connect the ItsyBitsy MCU to the computer using a microUSB cable. In Tools menu of Arduino IDE, select the correct board and port. Also, if using Itsy Bitsy M4, select Tools->USB stack->TinyUSB.

  4. First, you need to format the QSPI flash storage included on the board. To do so, find in the menu File->Examples->Adafruit SPIFlash->SdFat_format. Edit the line

    #define DISK_LABEL    "EXT FLASH"

    replacing EXT FLASH by a label of your choice, up to 11 symbols (e.g. “POVSTAFF”). Upload the sketch to your board and start the serial monitor at 115200 baud. You should see a message asking you to confirm reformatting; respond “OK” to confirm and you should see message “Formatted flash”.

  5. Now, you are ready to upload the POV firmware. Download the latest release of POV staff project from github repository if you haven’t done so already. Extract the archive file and find there folder code/povstaff. Copy the povstaff folder to your Arduino sketch folder. Open the sketch file povstaff.ino inside povstaff folder in Arduino IDE.

  6. Click Upload to compile and upload the code. It can take a while (mostly due to use of FastLED, which is a massive library). Once you get the message Done uploading, the programming is complete.

  7. Press Reset button once (or disconnect and reconnect the USB cable) to restart the ItsyBitsy. It should now appear as an external drive with the name POVSTAFF (or whatever name you have chosen in step 4) in your computer, which should be empty. Find in the extracted archive folder images and drag and drop files rg-lines.bmp and imagelist.txt to POVSTAFF. Eject the POVSTAFF drive and disconnect the USB cable; it is now ready for use.