QwiicBus EndPoint — i2C range — sensor not detected

Qwiic System
1

Hi !

I’m trying to connect two BNO055 (https://learn.adafruit.com/adafruit-bno … ion-sensor) through ethernet cat6 cable with the QwiicBus kit ( 2 endpoint and 1 midpoint). https://learn.sparkfun.com/tutorials/sp … okup-guide

But i have a really not stable system and sensors are not detected at all as soon as i use the QwiicBus (working fine with two sensors directly in the ArduinoUno)

I read the Hoockupp Guide and checked my cables.

To find a bit more where is the problem I just used one sensor connected to endpoint.

I’m using the real_all_data.ino from the BNO055 documentation.

And also run a i2C scanner and no sensor is detected .

This is my set up :

BNo055 Vin to 3.3V Endpoint

BNo055 GND to GND Endpoint

BNo055 SDA to SDA Endpoint

BNo055 SCL to SCL Endpoint

— cat6 cable —

[primary Endpoint is set up to use 5v (alternate 1)

the 0-1 jumper is OPEN and the 0-1 jumper on the last Endpoint is CLOSED]

Endpoint VCC1 to 5V Arduino

Endpoint 3.3V to 3.3V Arduino

Endpoint GND to GND Arduino

Endpoint SDA to A4 Arduino

Endpoint SCL to A5 Arduino

Do you guys have any idea ? or went through a similar problem ? Any input will be appreciated

2

…are you also using the midpoint? Please note:

Bypass (BP) Jumper - MidPoint

The Bypass jumper (labeled BP on the board) nets VCC1 with the 3.3V rail on the MidPoint. By default, this jumper is CLOSED. When the QwiicBus system is powered at 3.3V, this jumper can remain closed but if the PSEL jumper is adjusted to use anything over 3.3V to power the QwiicBus, this jumper must be OPEN.

Power Select (PSEL) Jumper - MidPoint

This dual jumper selects which voltage supplies the input voltage for the MidPoint buck regulator. The Power Select jumper defaults to all open and the buck regulator is unpowered. In this default setting, power for each EndPoint is 3.3V and provided over the Blue pair of the Ethernet cable from the microcontroller/SBC or dedicated 3.3V power supply.

If using the 5V power configuration, this jumper should be closed to set it to the “1” side. When set to “1”, the input voltage is still provided over the Blue pair of the Ethernet cable but at 5V.

If using the 3.8V-36V power configuration, close the jumper to set it to the “2” side. When set to “2”, input voltage is provided over the Green pair of the Ethernet cable.

Important! If either alternate setting of the PSEL Jumper is used, the Bypass Jumper must be OPEN.

GND1 and GND2 Jumpers - MidPoint

The GND1 and GND2 jumpers net both input voltages to a common ground. Both jumpers are CLOSED by default. In advanced-use cases, users can open one or both of these jumpers to reduce noise and/or prevent ground loops on QwiicBus boards further down the chain. Most users will want to leave these jumpers alone.

3

Hi,

Thank you for your answer.

Indeed i’m using also the midpoint. (with bypass OPEN and PSEL on 1).

This is my set up when i’m using midpoint :

BNo055 (n°1) Vin to 3.3V Endpoint (last)

BNo055 (n°1) GND to GND Endpoint (last)

BNo055 (n°1) SDA to SDA Endpoint (last)

BNo055 (n°1) SCL to SCL Endpoint (last)

— cat6 cable —

MIDPOINT (bypass OPEN and PSEL on 1)

Midpoint GND to GND BNo055 (n°2)

Midpoint 3V3 to Vin BNo055 (n°2)

Midpoint SDA to SDA BNo055 (n°2)

Midpoint SCL to SCL BNo055 (n°2)

— cat 6 —

[primary Endpoint is set up to use 5v (alternate 1)

the 0-1 jumper is OPEN and the 0-1 jumper on the last Endpoint is CLOSED]

Endpoint VCC1 to 5V Arduino

Endpoint 3.3V to 3.3V Arduino

Endpoint GND to GND Arduino

Endpoint SDA to A4 Arduino

Endpoint SCL to A5 Arduino

Still none of my IMU are detected.

( when i check with a multimeter every pin is correctly powered ( Vin, SDA, SCL to 5v) ) and they’re working fine directly on an arduino )

4

It might be helpful if you could share a photo of your current setup/wiring

First, let’s make sure the devices themselves are working properly - can you try to hook up JUST the endpoints, and see if they can communicate?

Next, try ONE endpoint, and the midpoint (and then try the other endpoint), and verify that they are able to talk to one another

After we know that they boards are functional, we can troubleshoot further