Mbed OS 2 and Mbed OS 5
This is the handbook for Mbed OS 2. If you’re working with Mbed OS 5, please see the new handbook.
This diagram shows the commonly used interfaces and their pinout locations. Note that all the numbered pins (p5-p30) can also be used as DigitalIn and DigitalOut interfaces. Some pinout options are not shown here; for a full details, see the technical reference below for the full pinout specification
This mbed Microcontroller is based on a Cortex-M3 Core running at 96MHz, with 512KB FLASH, 64KB RAM and a load of interfaces including Ethernet, USB Device, CAN, SPI, I2C and other I/O.
- 40-pin DIP package
- 0.1. pitch, 0.9. pin spacing
- 54mm x 26mm
- Powered by USB or 4.5v - 9.0v appiled to VIN
- <200mA (100mA with Ethernet disabled)
- Real-time clock battery backup input VB
- 1.8v - 3.3v Keeps Real-time clock running
- Requires 27uA, can be supplied by a coin cell
- 3.3v regulated output on VOUT to power peripherals
- 5.0v from USB available on VU (only available when USB is connected!)
- Current limited to 500mA
- Digital IO pins are 3.3v, 40mA each, 400mA max total
- Vin - External Power supply to the board
- 4.5v-9v, 100mA + external circuits powered through the Microcontroller
- Vb - Battery backup input for Real Time Clock
- 1.8v-3.3v, 30uA
- nR - Active-low reset pin with identical functionality to the reset button.
- Pull up resistor is on the board, so it can be driven with an open collector
- IF+/- - Reserved for Future use
Power and Logic Levels¶
The microcontroller I/O is all 3.3v logic, but 5v tolerant. A digital pin can drive 40mA, up to a total of 400mA.