xChip Bridges (Bxxx) are interfaces or connection points between the Xinabox/xChip eco-system and specific Single Board Computers (SBC).
All bridges provides 3.3 volt power and I2C Interface (levelled to 3.3 volt) from the SBC to the connected xChips. Most of the bridges also provides UART (Serial, RS232C) communication, but levelled to 3.3 volt. Bridges for SBCs that doesn't natively provide either 3.3 volt will have the voltage regulated to 3.3 volt to provide correct power for the xChip eco-system. Likewise, bridges for SBCs that doesn't signal using 3.3 volt on the I2C Interface and/or the UART Interface, also have the signals levelled to 3.3 volt to suit the default communication in the xChip eco-system.
For all boards, the standard assembly is that the bridge and connected xChip faces over the SBC. Minnowboard and 96Boards uses the full bus, so assembly is easy. For Raspberry Pi the bridges is connected using the pins nearest to the SD card and for BeagleBone the pins nearest to the 5V DC connector. See Specific Usage below for pictures of exact assembly.
Most Single Board Computers can run a variant of the Linux Operating System. Using
i2cdetect utility with a sensor xChip (Sxxx) connected to the bridge, allows you to quickly test correct connection. See the reference to the utilised I2C Interface (if more than one are available on the SBC) under each SBC under Specific Usage below. Activation of the I2C Interface on your SBC and the installation of the
i2cdetect utility is beyond the scope of this Wiki.
The main communication method between the xChips are I2C. The various single board computers are utilising this protocol differently, please click on the below link for your SBC/Bridge to see how to use the specific SBCs I2C.
Most bridges, but only a few xChips communicates using UART. The UART is mainly used for programming of cores with preprogrammed boot loader. However, to use the UART you have to make sure that your bridge is in either DTE or DCE and your connected xChip is in the opposite. See more on the UART page.
|Bridge||Single Board Computer|
|BeagleBone||BeagleBone Black, BeagleBone Green |
|micro:bit||Micro:Bit , MXChip |
|Minnowboard LSE||Minnowboard |
|Raspberry Pi||Raspberry Pi, Raspberry Pi Zero |