# I2C Level Converter with Bar30 Pressure Sensor

**URL:** <https://discuss.bluerobotics.com/t/i2c-level-converter-with-bar30-pressure-sensor/797>\
**Category:** Sensors\
**Created:** [February 28, 2017, 8:33pm UTC](https://discuss.bluerobotics.com/t/i2c-level-converter-with-bar30-pressure-sensor/797 "2017-02-28T20:33:40Z")\
**Posts on this page:** 1\
**Showing post:** 43

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**Author:** ![jwalser](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/jwalser/32/2234_2.png) [@jwalser](https://discuss.bluerobotics.com/u/jwalser)\
**Post date:** [August 29, 2017, 12:19pm UTC](https://discuss.bluerobotics.com/t/i2c-level-converter-with-bar30-pressure-sensor/797/43 "2017-08-29T12:19:26Z")

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@Owen Atmospheric variation can offset the pressure reading by up to a few decimeters. Yes, you will need to calibrate it by subtracting this offset to ‘zero’ or ‘tare’ the reading. This is what we do in the ArduSub software on our ROVs.

We do test every sensor, it is possible (but not likely) that one was missed or malfunctioning. @pam, Can you please carefully double check all of the points made in this thread? I think that you are experiencing the same issue as @Owen, and that if you were to solder the green wires (or use new crimped jumpers), it will work.

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