The MyoWare 2.0 Wireless Shield is designed to take in readings from the MyoWare 2.0 Muscle Sensor and wirelessly transmit sensor data with the ESP32-WROOM! This shield also includes a built-in LiPo battery to remotely power the muscle sensor and the ESP32 module. The Wireless Shield is equipped with snap connectors and low-profile pogo pins on the board, so you can easily stack it on the top side of the MyoWare 2.0 Muscle Sensor. Simply select a Power Source and flip the power switch to the ON position to give the sensor all the power it needs to work its myoelectric magic.
The board's USB type C and CH340 USB-to-serial converter enable programming via serial using the Arduino IDE. As you might expect, a reset button resets the ESP32. Various protection circuits are built into the board: ESD protection diodes for the USB data lines, a resettable PTC fuse for VUSB, and ideal diodes for protection on the VUSB and VBATT nets.
Each board comes with a 40mAh single-cell lithium polymer (LiPo) battery connected to it. The battery can be recharged through the USB Type C connector, and its dedicated LiPo charging circuit is set to a charge rate of about 40mA. Operating your MyoWare 2.0 Muscle Sensor on battery power and transmitting data wirelessly allows for complete isolation from the power grid.
Power is regulated down to 3.3V. Users can select their power source as well as turn on/off the board with included switches. A button to manually place the ESP32 in bootloader mode is populated as well. This button can also be used as a general purpose button as well. The board is equipped with two horizontal Qwiic connectors and 2.2kΩ pull-up resistors if you decide to include additional Qwiic-enabled devices. Standard 0.1"-spaced plated through holes (PTHs) break out a few of the ESP32 module's pins on the edge of the board for users.
This board also includes status LEDs for power (PWR), charge status (CHG), user LED (13), and envelope (ENV). There are additional jumpers for power (PWR), USB shield (SHLD), reference (REF), raw EMG (RAW), envelope (ENV), and I2C pull-up resistors (I2C). Use it as a teaching tool to reduce the number of wires in your system or add some myoelectric flair to your Halloween costume!