This breakout contains the BNO055 9 axis absolute orientation sensor which contains a ARM Cortex-M0 to digest the data from the gyroscope, magnetometer and accelerometer which are inside the chip, the BMP388 which precisely measures barometric pressure and altitude and finally the SHT35-D which very precisely measures temperature and humidity to within 0.2°C, 1.5% RH. All these sensors are programmable over I2C, the BMP388 also works with SPI and the BNO055 works over UART and HID-I2C as well as I2C. All of these chips allows the I2C address to be changed and the breakout will allow this through soldering jumpers.
Firstly and unfortunately, I have decided to put this project on hold t as I have decided the sensors are not an important part of my Pi Portable Recorder at the moment and will probably not be included in the final product. However, I am still on a mission of creating the best sensor breakout and for this reason, I have some big changes - instead of the BNO055, I plan on using the FXOS8700 and FXAS21002 which will still include a accelerometer, magnetometer and gyroscope and shouldn't have an issue with clock stretching as well as being more accurate. I plan on still using the BMP338 but am on the lookout for a cheaper replacement for the SHT35-D. I will post here when I start working on schematics for the new board.
After, checking the schematic against datasheets and other people's schematics, I have tweaked a few connections (or added missing ones) and now the basic schematic is ready (see attached image). The top left sensor is the BMP388 (pressure), the top right one is BNO055 (Absolute Orientation) and the bottom one is the SHT35-D (temperature and humidity).
Please note these schematic are not the final version. I need to at least add shared I2C connections. Also, I will add a voltage regulator, logic level converters, reset buttons and MOSFETs.
Edit - I noticed I forgot to connect the VSS pin to ground on the SHT35-DIS-B. This will be fixed in the next schematic I release.
Just a quick update to say I have finished the basic schematic. Before I upload it to here I plan on adding some extra features to improve ease of use. Firstly, I plan on adding MOSFETs so power is not wasted if you do not use a certain sensors as well as voltage regulators and logic level converters to allow the breakout to be used with a wide range of microcontrollers. Also, I also plan on adding buttons to the reset pins of the SHT35-D and BNO055.
Just a quick log to schematic should be uploaded he midweek. I have just got to check them and add buttons for the reset pins. If you have any questions please do ask.