This board is based on the ESP32 WiFi and Bluetooth enabled microcontroller , the successor of the ESP8266, the well known microcontroller from Espressif that is extensively used by the maker community.
Additionally, this board includes a wide variety of sensors and peripherals already connected to the ESP32, allowing users to start creating more complex projects out of the box without the need of soldering or having to connect a lot of wires. The board is shown in figure 1.
Figure 1 – Fish32 Seed board.
As mentioned, this board is based on the ESP32 microcontroller, which means that it has connectivity to WiFi and Bluetooth. Additionally, the ESP32 is a dual core microcontroller, which means it has plenty of power to deal with communication protocols and interaction with peripherals, making it a very good choice for Internet of Thing projects.
In terms of additional communication peripherals, it contains a LoRa Module, making it suitable for long range wireless communications. The module used is an Ai-Thinker Ra-02 LoRa module, based on the SX1278 chip. The ESP32 is connected to this module via SPI.
It also contains a WIZnet W5500 Ethernet module, giving an alternative way of connecting the ESP32 to the Internet, other than WiFi. This module is also connected to the ESP32 using the SPI interface.
In order to be able to show information to a user, the board includes a SSD1306 OLED display, controllable via the I2C interface. Note however that the OLED is not embedded in the board, but rather attached to it on top of a row of 4 connectors. The display is shown in more detail in figure 2.
Figure 2 – Display mounted on the board.
Regarding sensing capabilities, the board contains a MPU-9250 chip, which is a 9 axis Motion Processing Unit. More precisely, this device features a 3 axis MEMS Gyroscope, a 3 axis MEMS accelerometer and a 3 axis MEMS magnetometer. Although the chip also supports SPI, it is connected to the ESP32 using the I2C interface.
Additionally, the board has a APDS-9960 sensor, which can be used as an optic proximity sensor, ambient light sensor, RGB color sensor and gesture detection sensor . This is a very interesting and not so usually seen sensor that can be used for some creative projects.
In order to expand the GPIO capability of the ESP32, the Fish32 Seed Board includes a e SN7325 chip, which adds 16 more GPIOs, controllable via I2C .
Finally, the board has a ATECC508A cryptographic chip and a DRV8835 dual-H-bridge motor driver, the later one allowing to drive two DC motors or one stepper motor . The board also has an interface for connecting a micro SD card, as shown in the bottom right of figure 3.
Figure 3 – Side of the board, with the SD card connector.
In terms of size it is a relatively big board, due to the high number of additional peripherals, measuring 80 x 70 x 5 mm .