The device is connected to the application processor I2C bus, and for the V1 revision this I2C bus is also shared to two pins on the edge connector.
The accelerometer measures acceleration in 3 axes, and the magnetometer can be used as a compass, as well as a magnetic field detector. There is one combined motion sensor IC on the micro:bit, that contains an accelerometer and a magnetometer. This processor does not have any connection to the GPIO pins on the micro:bit. A TVS device is fitted to suppress ESD spikes and out of range voltages that could be present on the USB connector. The interface processor also contains an on-board regulator that steps down the USB voltage to 3.3V suitable for powering the rest of the micro:bit, and you can draw 120mA V1/300mA V2 from this processor regulator.
#Fritzing schematic serial#
It also provides a Connected Device Class that allows a serial port interface to be used across the USB.
#Fritzing schematic code#
The USB protocol handler on this processor implements a Mass Storage Class device in order to offer the drag and drop code load interface. This provides a method for loading code onto the application processor, using a drag and drop interface. The Interface sheet shows the KL26 V1/KL27 V2 processor, which is an NXP microcontroller with an Arm processor, that implements the USB protocol for the USB connector. Some of the Columns appear on the edge connector, so if you want to use extra GPIO pins, you have to disable the display in software.
#Fritzing schematic software#
This software also uses the LED Row and Col pins to implement the light sensing feature, as such you may see a difference in sensitivity between board revisions. The LED matrix is driven via a high-speed multiplex generated by application processor software. Row 2 Col 8, and Row 2 Col 9 are not used. On the V2 board this is implemented as a 5x5 matrix, but in the V1, this is implemented as a scanned matrix of 9x3 (i.e. The LED matrix is physically laid out as a 5x5. Schematicsīelow is the pinmap and allocation of the nRF52833, more information is available on the micro:bit V2 schematic GPIO on nRF52833īelow, we’ve extracted some useful details about the hardware that anyone implementing software for the micro:bit, interfacing to it, or designing an add-on board for it should find useful. If you’re looking to make something of your own based on the micro:bit, you might prefer to use our ‘Reference Design’ which is based on a radio module and has space on the layout for you to add your own components. The micro:bit V2 schematic is available from the Micro:bit Educational Foundation microbit-v2-hardware repository. The micro:bit V1.3 and V1.5 schematic is available from the BBC’s micro:bit hardware repository. This page discusses the micro:bit schematic and Bill of Materials BOM, which shows the electrical connections of the micro:bit and the components used in it.