Cannot create more than one instance

[dhalbert]

Attempting to create more than one Adafruit_BNO08x fails, because i2c_dev is a static global, and gets discarded and re-created on the second call to the Adafruit_BNO08x constructor. I believe the i2c_dev should be a field in the device object.

See https://discord.com/channels/327254708534116352/537365760008257569/1273319381597687828 for a thread about this.

[dhalbert]

I'm not sure if the sensor_id argument is necessary, since different instantiations could be distinguished by object identity.

[dhalbert]

This is not so easy to fix, because the underlying library we use, https://github.com/ceva-dsp/sh2, is not re-entrant and only supports one sensor at a time. The SparkFun library is derived from ours; this problem was brought up there:
sparkfun/SparkFun_BNO08x_Arduino_Library#3
and then an issue was opened on the original library:
ceva-dsp/sh2#9
This was November 2023, not sure if there will be any movement on this.

[iLoveAndyBaker]

It's not just one sensor per bus either - it's just ONE sensor. Period.

[VICLER]

I found out that the SparkFun BNO080 old library (https://github.com/sparkfun/SparkFun_BNO080_Arduino_Library) works well with more than one BNO085 sensors on i2c bus. There are 2 addresses, so you can get up to 4x bno085 working on esp32 (with 2x i2c ports). But it does not work with SPI for some reason.. For my project I need 5x sensors, so I am using sparkfun bno080 for 4x sensors over i2c and one with sparkfun bno08x over spi.

[Lunatunny]

ras-marques found that the BNO080 library from SlimeVR supports multiple BNO085 sensors just fine too. I grabbed their BNO080.cpp and .h (https://github.com/SlimeVR/SlimeVR-Tracker-ESP/tree/a4a9778f62d0b962c46898d03e9ce70171a1ca12/lib/bno080) and they worked perfectly on my ESP32 through the arduino IDE. For implementation examples, checkout https://github.com/SlimeVR/SlimeVR-Tracker-ESP/blob/a4a9778f62d0b962c46898d03e9ce70171a1ca12/src/sensors/bno080sensor.cpp#L33 and https://github.com/ras-marques/ImmersiveGloves/blob/main/Firmware/RightHand/usb1/usb1.ino

[VICLER]

ras-marques found that the BNO080 library from SlimeVR supports multiple BNO085 sensors just fine too. I grabbed their BNO080.cpp and .h (https://github.com/SlimeVR/SlimeVR-Tracker-ESP/tree/a4a9778f62d0b962c46898d03e9ce70171a1ca12/lib/bno080) and they worked perfectly on my ESP32 through the arduino IDE. For implementation examples, checkout https://github.com/SlimeVR/SlimeVR-Tracker-ESP/blob/a4a9778f62d0b962c46898d03e9ce70171a1ca12/src/sensors/bno080sensor.cpp#L33 and https://github.com/ras-marques/ImmersiveGloves/blob/main/Firmware/RightHand/usb1/usb1.ino

That is the same SparkFun BNO080 library..

[Lunatunny]

oh LOL that's literally what you said how did i not see that

[zhaolun7]

ras-marques found that the BNO080 library from SlimeVR supports multiple BNO085 sensors just fine too. I grabbed their BNO080.cpp and .h (https://github.com/SlimeVR/SlimeVR-Tracker-ESP/tree/a4a9778f62d0b962c46898d03e9ce70171a1ca12/lib/bno080) and they worked perfectly on my ESP32 through the arduino IDE. For implementation examples, checkout https://github.com/SlimeVR/SlimeVR-Tracker-ESP/blob/a4a9778f62d0b962c46898d03e9ce70171a1ca12/src/sensors/bno080sensor.cpp#L33 and https://github.com/ras-marques/ImmersiveGloves/blob/main/Firmware/RightHand/usb1/usb1.ino

That is the same SparkFun BNO080 library..

Not exactly the same. after comparing the lib the SlimeVR version might copy from SparkFun in 2021 and maintain itself from then. SparkFun has stopped maintainance from 2023.