Adafruit Huzzah32

The Huzzah32 is one of the development board created by Adafruit that mounts on-board the official WROOM32 module. The Huzzah32 device features built-in USB-to-Serial converter, automatic bootloader reset, Lithium Ion/Polymer charger, and all the GPIO brought.

Adafruit Huzza32 contains a dual-core ESP32 chip, 4 MB of SPI Flash, tuned antenna, and The ESP32 microcontroller has both WiFi and Bluetooth Classic/LE support.

Adafruit Huzzah32

Pin Mapping

Adafruit Huzzah32

Official reference for Adafruit Huzzah32 can be found here.

Flash Layout

The internal flash of the ESP32 module is organized in a single flash area with pages of 4096 bytes each. The flash starts at address 0x00000, but many areas are reserved for Esp32 IDF SDK and Zerynth VM. In particular:

Start address Size Content
0x00009000 16Kb Esp32 NVS area
0x0000D000 8Kb Esp32 OTA data
0x0000F000 4Kb Esp32 PHY data
0x00010000 1Mb Zerynth VM
0x00110000 1Mb Zerynth VM (FOTA)
0x00210000 512Kb Zerynth Bytecode
0x00290000 512Kb Zerynth Bytecode (FOTA)
0x00310000 512Kb Free for user storage
0x00390000 448Kb Reserved

Device Summary

  • Microcontroller: Tensilica 32-bit Single-/Dual-core CPU Xtensa LX6

  • Operating Voltage: 3.3V

  • Input Voltage: 7-12V

  • Digital I/O Pins (DIO): 28

  • Analog Input Pins (ADC): 8

  • Analog Outputs Pins (DAC): 2

  • UARTs: 3

  • SPIs: 2

  • I2Cs: 3

  • Flash Memory: 4 MB

  • SRAM: 520 KB

  • Clock Speed: 240 Mhz

  • Wi-Fi: IEEE 802.11 b/g/n/e/i:

    • Integrated TR switch, balun, LNA, power amplifier and matching network
    • WEP or WPA/WPA2 authentication, or open networks

Power

Power to the Adafruit Huzzah32 is supplied via the on-board USB Micro B connector or directly throught the connector for a 3.7/4.2 V battery. The power source is selected automatically.

The device can operate on an external supply of 2.5 to 6 volts. If using more than 6V, the voltage regulator may overheat and damage the device.

Connect, Register, Virtualize and Program

The Adafruit Huzzah32 exposes the serial port of the ESP32 module via a CP2104 usb bridge which is also connected to the boot pins of the module, allowing for a seamless virtualization of the device.

Note

Drivers for the bridge can be downloaded here and are needed for Windows and Mac platforms.

Note

For Linux Platform: to allow the access to serial ports the user needs read/write access to the serial device file. Adding the user to the group, that owns this file, gives the required read/write access:

  • Ubuntu distribution –> dialout group
  • Arch Linux distribution –> uucp group

Once connected on a USB port, if drivers have been correctly installed, the Huzzah32 device is recognized by Zerynth Studio. The next steps are:

  • Select the Adafruit Huzzah32 on the Device Management Toolbar (disambiguate if necessary);
  • Register the device by clicking the “Z” button from the Zerynth Studio;
  • Create a Virtual Machine for the device by clicking the “Z” button for the second time;
  • Virtualize the device by clicking the “Z” button for the third time.

Note

No user intervention on the device is required for registration and virtualization process

After virtualization, the Huzzah32 is ready to be programmed and the Zerynth scripts uploaded. Just Select the virtualized device from the “Device Management Toolbar” and click the dedicated “upload” button of Zerynth Studio.

Note

No user intervention on the device is required for the uplink process.

Firmware Over the Air update (FOTA)

The Firmware Over the Air feature allows to update the device firmware at runtime. Zerynth FOTA in the Huzzah32 device is available for bytecode and VM.

Flash Layout is shown in table below:

Start address Size Content
0x00010000 1Mb Zerynth VM (slot 0)
0x00110000 1Mb Zerynth VM (slot 1)
0x00210000 512Kb Zerynth Bytecode (slot 0)
0x00290000 512Kb Zerynth Bytecode (slot 1)

For Esp32 based devices, the FOTA process is implemented mostly by using the provided system calls in the IDF framework. The selection of the next VM to be run is therefore a duty of the Espressif bootloader; the bootloader however, does not provide a failsafe mechanism to revert to the previous VM in case the currently selected one fails to start. At the moment this lack of a safety feature can not be circumvented, unless by changing the bootloader. As soon as Espressif relases a new IDF with such feature, we will release updated VMs.

Missing features

Not all IDF features have been included in the Esp32 based VMs. In particular the following are missing but will be added in the near future:

  • BLE support
  • Touch detection support
  • Real time clock support
  • Watchdog support (however, global watchdog is active by default)