The OpenROV project began shipping version 2.5 of its Linux-based, $849 underwater robot kit. The open source OpenROV 2.5 design advances to a 1GHz BeagleBone Black SBC, scraps the earlier BeagleBone cape in favor of a faster Arduino-compatible controller board design, and boasts improvements to buoyancy, durability, speed, and battery life.

It’s been over a year since the OpenROV project successfully completed its Kickstarter campaign, but only a few hundred kits have been sold to date. Now, with a much improved version 2.5 available, and a recent investment of $1.3 million led by True Ventures, the project appears ready to expand.

OpenROV 2.5 runs Linux on a BeagleBone Black
(click images to enlarge)

So far, however, there are no clear plans for finished products. It’s still an open source kit project designed for its growing community of DIY ocean explorers from around the world. Hobbyists and scientists have used the foot-long, tethered submarines to hunt for hidden gold in flooded caves in California, explore cenotes in the Yucatan, and dive with whales in the open ocean.

Earlier OpenROV in its element
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The OpenROV has been one of the more significant design wins for the BeagleBone. The new 2.5 version of OpenROV, which was unveiled this last weekend at Maker Faire New York, now moves up to the BeagleBone Black, giving its Linux operating system a faster 1GHz TI Sitara processor and a lower $45 price, among other benefits.

What’s included in the OpenROV 2.5 kit
(click image to enlarge)

In addition to the upgraded processor board, OpenROV version 2.5 also replaces the earlier Arduino-compatible BeagleBone cape add-on with a custom-made controller board that is said to greatly reduce wiring. The new controller board runs Arduino code on a faster Atmega 2560 processor, and supplies more DIO, A/D, and PWM interfaces.

Specific controller board improvements include:

• 4x “Power PWM” channels with switchable supply voltage
• 6x servo output channels with male headers
• Current sensing for each battery, controller board, and ESC
• Voltage and temperature sensors with optional humidity sensor
• UART and SPI connections between BeagleBone and ATmega
• DB-25 connector for wiring harness easier to use and modify than earlier molex

The new structural design of the sub is intended to be easier and faster to build, as well as easier to modify and debug. Structural changes and new propellers also make it faster, more buoyant, and more durable, says the project.

Some of the main structural changes on OpenROV 2.5 include:

• Polypropylene shell — compared to earlier acrylic, it’s more durable and buoyant, with tighter tolerances; semi-translucent
• Graupner propellers — 200 percent more efficient for faster speed; twice the battery life
• Battery tube design — clear PETG tube construction with O-ring-based endcaps and potting-sealed rear endcaps for greater leak resistance at depth
• Other structural — double tabs for shell mounting, for greater durability; stronger endcap flange; wider structure with more internal space for adding components including USB cabling direct to BeagleBone
• Camera — independently rotating camera and light platform with HD video, wide-angle lens, and tilt function
• Laser rangefinders — 2x laser emitters for distance and size calculation

The device would appear to be fairly similar sized, but slight wider, than version 2.3, which measures 30 x 20 x 15cm, and weighs 2.5 kilograms. Based on the above claims, it would appear to go faster than the earlier 1 meter per second, and its batteries are also said to last longer as well. The device can run on standard C batteries, but rechargeable lithium batteries and a charger are available for $72.

Version 2.5 still runs on three FalconSEKIDO brushless motors, with two horizontal and one vertical thruster. It’s unclear whether it can descend past the earlier record of 25 meters in depth. The goal of the project is 100 meters, and a 100-meter tether with 10/100 Ethernet is provided in the kit. (WiFi, sadly, is not usable underwater). As before, users control the device via a connected laptop using a web browser UI.

Availability

The OpenROV 2.5 Kit is now available for $849, with shipments promised in one to two weeks. A Shell Only Kit without electronics costs $245. More information may be found in the OpenRov 2.5 announcement and at the OpenROV 2.5 Kit and Shell Only Kit pages.

According to a comment posted on the OpenROV blog today by David Lang, co-founder of the OpenRov project, the new controller board from the v2.5 kit is compatible with older BeagleBoard SBC and can be used for upgrading existing OpenROV 2.3 kits. “We’ll definitely have it in the store. It may take a week or two. We want to fill all the kit orders first. You’ll love the new board,” says Lang.