I’ve posted my final report for the MaSCOT project.

I haven’t discussed the results from initial MaSCOT testing in great detail — though some sample data has been posted.

One of the big take-aways for me was that two BlueRobotics Lumen R1 lights is simply not enough. Unfortunately, only two lights fit within the power budget dictated by my PoE system.

So, we went ahead and re-engineered the power system, purchased a new tether which includes both gigabit and power conductors, and purchased four more BlueRobotics lights. The rest of the system is still being assembled, but I daisy-chained the lights and did a first successful in-air test (with PWM control) today.

See also part 1, part 2 and part 3

I designed the board in Eagle, design files are on GitHub.

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The board is very straightforward. Lots of 0.1" header for connecting to the Jetson dev board and then breaking those pins out to pads. A TI MSP430FR2311 in a 20-pin TSSOP is the brains of the operation. I purchaed a MSP-FET just to have one around, and used the standard “full” 14-pin pinout using Spy-Bi-Wire for communications. The MSP-FET can power the companion board for testing (selected by JP9). The power and reset lines are grounded by 2N7002 FETs.

I’ve stared migrating my MaSCOT design files to Github:

• Project management files on Github
• Companion board design files on Github

TL;DR: I ended up needing to to design a micro-based “companion board” which handles power-on, watchdogging, out of band comms, and LED light control for the Jetson. The details can be found on GitHub.

See also part 1 and part 2

A primary concern for me was ensuring the system was as usable as possible while inside the housing. Opening and closing the housing is time-consuming and somewhat risky in terms of getting a repeatable seal. Unfortunately, the ethernet-only architecture severely limited my options for out-of-band communications to the system. That is, if the Jetons failed to boot, there would be no ethernet, and I’d be hosed.

Oct 27, 2016: I’ve moved the contents of this page to a more permanent location

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As described in part 1, the prototype system architecture is:

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The mechanical design was the one element I did not handle myself. I worked with a mechanical engineer at APL to design an inexpensive, easy to machine shallow water housing with enough space for the Zed and Jetson. The final design consists of a single 12" x 12" block of Delrin with a single cavity hogged through it. The front and back faces have o-ring seals and tapped holes for retaining bolts for the endplates, and a series of top-to-bottom through-holes along the sides provide mounting points.

I need to write a final report for the MaSCOT project during 2016. I thought drafting the report as a series of blog posts would kill two birds with one stone…

This is an introduction the Marinized Stereo Camera Operational Testbed (MaSCOT), an internal R&D project supported by the APL Science and Engineering Group (SEG). The project had multiple goals:

1. to procure one or more stereo vision cameras and package them for shallow-water underwater testing;
2. to any sort of machine vision camera at all for use underwater (which is mostly redundant with one); and
3. to support my serious engagement with at least one Open Source SLAM program – there is such a diversity of code available, I felt it was better to incrementally improve and existing codebase than start from scratch.

Besides hardware costs, the project supported a small amount of time for a mechanical engineer at APL to design and construct the camera housing. My time was supported under the APL postdoc program.

[Apologies that this is the first post about MaSCOT. I’ll try to keep up a development blog and backfill with add’l project notes and resources. Maybe.]

The full MaSCOT system has been assembled and is ready for tank testing.

I ran the sealed system on the desktop for the first time last night. While it was on I recorder internal air temperatures using the Bosch BMP280 on the companion board, plus the Linux ACPI temperature values.