New Depth/IMU Board is in stock!


Good news! We've got the new Depth/IMU board in stock and on the webstore. We have a limited number available to ship from this first batch. You can order one here:




But how you calculate the depth ? You calculate it in comparison to what ?


This module interfaces easily with the Version 2.5 OpenROV, but for those people who have Version 2.3 or 2.4, you can use this as well- it will just take a bit more work to hook it up.

You'll need to have 4 spare wires going through the endcap, for 3.3V power, ground, I2C data, and I2C clock. If you didn't pot any spare wires in your endcaps, you'll have to figure out a way to drill through one endcap, run some wires, and repot it.

Then, the depth/IMU board runs on 3.3V, while the Cape runs on 5V. There is a 3.3V supply pin on the Cape- that's where the Homeplug adapter gets its power- but the I2C bus on the Cape needs to be converted from 5V to 3.3V. That can be done with a bidirectional level shifter such as this.

John: The depth sensor is nothing more than a waterproof absolute pressure sensor. The ambient atmospheric pressure is subtracted off to get the pressure of the water column, which is then converted to depth. Since atmospheric pressure varies, especially if you're diving in a high mountain lake, there is a button in the software to zero the depth gauge as part of the pre-dive procedure.

The conversion from pressure to depth depends upon the density of water, which differs depending upon whether you're in fresh water or seawater. The current software is calibrated only for fresh water, but the next software drop will have a button that allows you to select whether you're in freshwater or seawater.




Looking forwards to installing this :)


Can't wait for the mail man to show up!


Hi Eric

I just ordered the Depth/IMU but I also want the New Cape and I see them in the store. Are these the new ones with the Home Plug Adapter change if so I will order it and all can be shipped together. Also is there any advantage to go with the BBB over the old one?


I meant this comment for David sorry Eric I will save my next one for you. :)


Hey David,
We don't have the updated controller board in yet. Which one did you want?



I was looking to get the new Cape if it has the changes that will accept the old Home Plug Adapter as well as the new Version.


Why does the PMU ship with two wafers for the bottom side? Also what type of epoxy do you recommend filling it with would the Hysol do ok?