Overview Iteadmaple is a microcontroller board based on Leaf Maple. The Iteadmaple can achieve the maximum 72 MHz it has 39 digital input/output pins 16 analog inputs native full speed USB 3 USARTs (hardware serial ports) integrated SPI/I2C support with power jack and reset button. Iteadmaple is programmable over USB via a provided DFU bootloader no extra hardware required! Users can also program the onboard program flash via external X-link/X-linkEx JTAG interface. Iteadmaple offers security support for read/write protected addresses as well as User and Handler processor modes.Iteadmaple can be powered by USB or external power supply. Feature 72MHz ARM Cortex M3 core 20KB SRAM and 128KB Flash 64 channel nested vector interrupt handle 7 channels of Direct Memory Access(DMA) Wide range external input from and USB supply adaptive X-link/X-linkEx full compatible Pins map full compatible for Arduino shield. Microcontroller STM32F103RB Max Frequency 72MHz RAM Capacity 16K FLASH Capacity 128K External Resources No Power Supply External 12V External 24V External 7V External 9V USB 5V I/O Operation Level 3.3V