ESP32-WROOM-32 (ESP-WROOM-32) is a powerful, generic Wi-Fi+BT+BLE MCU module that targets a wide variety of applications, ranging from low-power sensor networks to the most demanding tasks, such as voice encoding, music streaming and MP3 decoding. At the core of this module is the ESP32-D0WDQ6 chip. The chip embedded is designed to be scalable and adaptive.
There are two CPU cores that can be individually controlled, and the clock frequency is adjustable from 80 MHz to 240 MHz. The user may also power off the CPU and make use of the low-power co-processor to constantly monitor the peripherals for changes or crossing of thresholds.
ESP32 integrates a rich set of peripherals, ranging from capacitive touch sensors, Hall sensors, SD card interface, Ethernet, high-speed SPI, UART, I2S and I2C. The integration of Bluetooth, Bluetooth LE and Wi-Fi ensures that a wide range of applications can be targeted and that the module is future proof: using Wi-Fi allows a large physical range and direct connection to the internet through a Wi-Fi router while using Bluetooth allows the user to conveniently connect to the phone or broadcast low energy beacons for its detection.
The sleep current of the ESP32 chip is less than 5 µA, making it suitable for battery-powered and wearable electronics applications.
ESP32 supports a data rate of up to 150 Mbps, and 20.5 dBm output power at the antenna to ensure the widest physical range. As such the chip does offer industry-leading specifications and the best performance for electronic integration, range, power consumption, and connectivity. ESP32-D0WDQ6 contains two low-power Xtensa® 32-bit LX6 microprocessors.
The internal memory includes:
– 448 kB of ROM for booting and core functions
– 520 kB (8 kB RTC FAST Memory included) of on-chip SRAM for data and instruction
– 8 kB of SRAM in RTC, which is called RTC FAST Memory and can be used for data storage; it is accessed by the main CPU during RTC Boot from the Deep-sleep mode
– 8 kB of SRAM in RTC, which is called RTC SLOW Memory and can be accessed by the co-processor during the Deep-sleep mode
– 1 kbit of eFuse, of which 320 bits are used for the system (MAC address and chip configuration) and the remaining 704 bits are reserved for customer applications, including Flash-Encryption and Chip-ID.
ESP32-WROOM-32 (ESP-WROOM-32) integrates 4 MB of external SPI flash. The 4-MB SPI flash can be memory-mapped onto the CPU code space, supporting 8, 16 and 32-bit access. Code execution is supported. The integrated SPI flash is connected to GPIO6, GPIO7, GPIO8, GPIO9, GPIO10 and GPIO11. These six pins cannot be used as regular GPIO.
The operating system chosen for ESP32 is freeRTOS with LwIP; TLS 1.2 with hardware acceleration is built-in as well. Secure (encrypted) over the air (OTA) upgrade is also supported so that developers can continually upgrade their products even after their release. The ESP32 Devkit can be supported and programmed by Arduino IDE after installing the driver and board manager file.