At its heart, the SparkFun RedBoard Turbo uses the ATSAMD21G18 MCU, which is an Arm® Cortex® M0+ 32-bit microcontroller that can run up to 48 MHz. With an impressive 4 MB of external Flash memory and a UF2 (USB flashing format) bootloader, the RedBoard Turbo provides an economical and easy to use development platform with more power and versatility than the classic RedBoard.
The SparkFun RedBoard Turbo is equipped with a USB interface for programming and power, a Qwiic expansion connector, an RTC crystal, a WS2812-based addressable RGB LED, a 600 mA 3.3 V regulator, and a variety of other components. The RedBoard Turbo may be powered via the micro-B port, through the 5 V tolerant barrel jack, or with a LiPo battery using the onboard battery connector (for a single-cell 3.7 V to 4.2 V lithium-polymer battery). The MCP73831's charge current is configured by a resistor value between 66 kΩ and 2 kΩ, to charge the battery at a rate between 15 mA and 500 mA, respectively. By default, the board is configured to charge the battery at around 250 mA. The board layout meets the Arduino 1.0 footprint standard, including a separate SPI header and additional I2C header.
The RedBoard Turbo can even be flashed over the mass storage class (MSC) just like a removable flash drive, thanks to the UF2 bootloader. With this bootloader, the RedBoard Turbo enumerates as a USB storage device without having to install drivers. When using the Arduino IDE, users will need to select the correct port to program the board but can just as easily use another programming language such as CircuitPython or MakeCode.