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I have problems detecting an MPU-6050 I2C device on the Intel Edison Mini breakout board (it only supports 1.8V levels). According to the thread here, it might be possible to get the sensor working with 1.8V levels:

"The MPU-6050 also supports different supply (VDD) and I/O interface (VLOGIC) voltages. If your board allows you to make separate connections to VDD (on pin 13) and VLOGIC (on pin 8), leave VDD on 3.3V and connect VLOGIC to 1.8V. Connect the pull-up resistors on SDA and SCL to 1.8V. The MPU-6050 will then speak I2C directly at 1.8V, eliminating the need for a discrete level shifter."

Anyone can suggest how this setup might work (i.e. make a drawing) ?

Thanks!

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  • \$\begingroup\$ You understand that I2C uses OD outputs and is therefore not actively driven high, right? \$\endgroup\$ – Ignacio Vazquez-Abrams Jan 31 '16 at 13:10
  • \$\begingroup\$ hmm.. not having too much experience with this, when on arduino, it could attach the sensor SDA and SCL to the board, now on the edison nothing happens \$\endgroup\$ – poseid Jan 31 '16 at 13:16
  • \$\begingroup\$ so, i am feeling i miss something, but not sure if it is a circuit, or just making the wrong connections between pins. \$\endgroup\$ – poseid Jan 31 '16 at 13:17
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The I²C bus pullups and VLOCGIC on the MPU chip must be connected to the 1.8 Volt rail:

schematic

simulate this circuit – Schematic created using CircuitLab

The MPU-6050 still needs 3.3 Volts on its VDD pin. Note that this will only work if your MPU-6050 module has not connected VLOGIC to VDD in any way on the PCB.

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  • \$\begingroup\$ thanks! just curious, do you see a chance to level shift the edison 1.8V bus to the 3.3V for this MPU6050 board? 301o583r8shhildde3s0vcnh.wpengine.netdna-cdn.com/wp-content/… \$\endgroup\$ – poseid Jan 31 '16 at 14:05
  • \$\begingroup\$ There are specialized I²C level shifter ICs. Your board would need those, as VLOGIC is connected to 3V3 VDD rail. \$\endgroup\$ – Turbo J Jan 31 '16 at 14:38
  • \$\begingroup\$ just for reference, I saw the board example: sparkfun.com/products/13034 \$\endgroup\$ – poseid Feb 9 '16 at 8:34

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