Hello,
As an embedded system engineer with hands-on experience over 10 years, I can help with your design. I have also designed a data logger with sensors (temperature, light, gyro) including Bosch BNO055 via I2C and STM32F407 like yours. If you want I could make a quick demo.
I have worked many projects about PCB and schematics design, development in embedded C programming and code debugging.
I design, assemble and test prototype electronics with in-house equipment. For volume production, I can help you. I also have development boards as Arduino, Raspberry Pi, Beaglebone Black, etc.
Please send me a message so we can discuss more details.
Regards
fazli_kuzu