Scantlings

This is a little spinoff from my 3D printing efforts. I needed a computer that could be embedded with each printer. This computer runs on 12v and powers a RPi Zero/W. Total cost for all the parts is around $15.

I am not familiar with Open Cap'n or some of the other open source nav packages, but this could be a very useful device onboard.

Application wise, how is this better or worse than an Arduino?
I don't have a need or use for either but I'm thinking about a learning / teaching tool.
A few months back I installed BASIC on my win10 home PC, only because I vaguely remember how to do some of the programming I was thought at school and, well, it was raining and I wanted to try to teach my 11 yo what I can about what happens behind the screens in the world of computers.
Apart from BASIC at school my only "code writing" skills are with ladder logic with PLC's, I don't really see a lot of future in teaching ladder to an 11 year old. There are better codes out there,and I'm just to stubborn to learn them.
Mr 11 yo got to the point where he could fault find and correct simple errors in my basic BASIC programs but didn't really want to sit down and write a program himself.
Little wins I guess.
Anyway, Sorry for the hijack.

Jeroen.

No worries FD. Always happy to speak geek

Arduino and Raspberry Pi are basically apples and oranges... There's a pun in there somewhere.

Arduino is a controller. It's discrete in that it only does arduino stuff. Many years ago when I dabbled in automation, you would have to get individual controllers to do things like drive a motor or turn on lights. The Arduino can do all that using appropriate 'shields'.

Raspberry Pi is a full-blown computer. A PC if you will. They run many different flavors of Linux and there's even a build of Windows that can run on them. The RPi has USB and Video ports. You could literally make yourself a tiny home PC if you're just looking for something to surf the web and do basic stuff.

For kids, the robotics stuff with Arduino is much simpler than trying to tackle Linux on a RPi.

Nice case!

I use OpenCPN on a windows machine. Think of Expedition-lite. Big user base. Developer is on Cruiser's Forum.

Used BASIC in college. My daughter the engineer spent a lot of time on JAVA and C++.

Rick,

If you want to play with something really complex, folks are building giant clusters of Raspberry Pi systems and running Kubernetes on it. The great thing is that a battalion sized cluster can do some REAL WORK.

Article HERE

B

Thanks Son's. That makes perfect sense to me.
One day, when I think of a project I'll buy an arduino just to play.

Jeroen.

So, Back to my hijack....
My Mr 11 year old is doing Preforming Arts at school.
He comes home with some musical notes on a piece of paper that he has written, I want to hear his music...
I say to him that the computer speakers could play those notes, and that that there is a hard way for me to hear them, and an easy way.
Doesn't take him long to work out that the hard way is to write a program in BASIC and the easy way is to ask uncle Google.
He elects to do it the hard way.
I worked out the numbers to put into BASIC to get the notes (thanks uncle Google) and he sat down and entered the whole thing in.
I was only a very short piece of music but the way I got to hear it was a whole lot of fun.

Jeroen.

What a great story!! It's projects like that which change the life of a kid for the better. Some of my fondest and most frustrating memories are building things and solving problems with my Dad. Without that fun and torture, I could NEVER have accomplished what I have as an adult. Congrats on having a great kid and being a great Dad. Well done!!

floating dutchman wrote:So, Back to my hijack....
My Mr 11 year old is doing Preforming Arts at school.
He comes home with some musical notes on a piece of paper that he has written, I want to hear his music...
I say to him that the computer speakers could play those notes, and that that there is a hard way for me to hear them, and an easy way.
Doesn't take him long to work out that the hard way is to write a program in BASIC and the easy way is to ask uncle Google.
He elects to do it the hard way.
I worked out the numbers to put into BASIC to get the notes (thanks uncle Google) and he sat down and entered the whole thing in.
I was only a very short piece of music but the way I got to hear it was a whole lot of fun.

Jeroen.

MuseScore is a semi easy way. It's free composition software. Easy at first, but frustrating when it comes to fixing mistakes or entering more complicated music.

Rick,

Can I get some stats on that machine? I've been vacillating between building and installing something like that down at the nav station and just velcroing a tablet bluetooth-ing to the GPS puck.

For me, the turd in the punchbowl, is that I'll need to install KVM (keyboard/video/mouse) somehow. My nav desk is a fold-up desk and I *need* to retain that ability, thus the KVM stuff needs to be slim. I also can't decide if I want the KV to be bluetooth and battery powered, or hard cabled. Lastly, is there such a thing as a THIN, 12vdc monitor that doesn't cost a damned fortune?

You can see how a tablet just answers all of these questions but somehow, I'm still interested in a dedicated "navigator-in-a-can."

As far as KVM goes, I've used a wireless keyboard with built-in trackball at my navstation. The trackball is much better than a mouse when you have limited space and the boat is pitching and rolling. My navstation computer is a Windows machine, but I'm using a wireless K/M on a RPi and it is plug-and-play.

I've also got a small USB-connected monitor for the boat. It's very low power and gets power and video data over the USB connection. Here's a newer, bigger one (haven't tried this one myself, and can't promise RPi compatibility): https://www.newegg.com/Product/Product.aspx?Item=N82E16824160215

We use track balls at work for exactly those reasons.
Post what you build Ajax, looks like a fun little project.

VALIS wrote:As far as KVM goes, I've used a wireless keyboard with built-in trackball at my navstation. The trackball is much better than a mouse when you have limited space and the boat is pitching and rolling. My navstation computer is a Windows machine, but I'm using a wireless K/M on a RPi and it is plug-and-play.

I've also got a small USB-connected monitor for the boat. It's very low power and gets power and video data over the USB connection. Here's a newer, bigger one (haven't tried this one myself, and can't promise RPi compatibility): https://www.newegg.com/Product/Product.aspx?Item=N82E16824160215

Oooh, this may be just what the Doctor ordered. I'm collaborating with a co-worker. Since the hardware is so damned cheap, we might build a dedicated nav-puter this winter.

My requirements-

12vdc systems with no inverters or DC-DC convertors.
Withstand temperatures from 25F to 100F.
Powerful enough to run OpenCPN without lag or fidgeting.
Bluetooth for communing with the GPS puck/keyboard/mouse or support of cabled keyboard/mouse.
Monitor thin enough to fit on the partition and not interfere with the nav table folding up.

Optional requirements-

Ability to run a light browser for checking weather and downloading chart updates
Wi-Fi.

The brain will live in a hidey-hole right next to the nav station. This really should be child's play.

re: DISPLAY

You might want to take a close look at some of the cases. Many add a back bezel which could be a much smaller. Because normal city-dwellers don't care about the difference between a 3/8" and a 3/4" thick screen, the mfg. doesn't bother to really make the thing ultra-thin. You may be able to remove the back bezel and attach the resulting thinner screen to the bulkhead.

Also, depending on how much wood working you want to do, a router can make a nice indent in your bulkhead into which you can insert the screen

(I love making work for people with suggestions )

Looks like a reasonable machine. I admit I like the Lenovo as a mid priced laptop with lots of features and I'm a sucker for SSDs (bought my first 512G SSD 5.5 years ago and it's still running fine. ) A Hybrid of a smaller SSD for the OS and files in use and a large spinning drive is a pretty good compromise on price/performance.

BeauV wrote:re: DISPLAY

You might want to take a close look at some of the cases. Many add a back bezel which could be a much smaller. Because normal city-dwellers don't care about the difference between a 3/8" and a 3/4" thick screen, the mfg. doesn't bother to really make the thing ultra-thin. You may be able to remove the back bezel and attach the resulting thinner screen to the bulkhead.

Also, depending on how much wood working you want to do, a router can make a nice indent in your bulkhead into which you can insert the screen

(I love making work for people with suggestions )

It's not really a bulkhead, it's just a thin, wood partition. I'm not sure how far I could really dig into it. The bezel idea is worth investigating though.
This monitor that Paul has linked looks pretty darned thin.

By the way, Amazon has that same monitor, and others too. The older one that I have is a Lenovo 1452-DM6, which seems to be the same as a Lenovo LT1421. It doesn't magically start working on a RPi3 (I just tried it), but here's a link to a posting from someone who did make it work: https://www.igorkromin.net/index.php/2015/03/14/lenovo-lt1421-usb-displaylink-monitor-on-a-raspberrypi/

The monitor is plug/play on my Windows machines. Note that there is no software-control of display brightness, just a "brighter/dimmer" button on the back of the panel. It gets reasonably bright, but I can't turn it down quite far enough to be as dim as I like for night work on the boat. It's not horrible, but it could be dimmer. If you need to adjust the screen brightness the location of the control might be a problem in your panel-mounted application.

Here's a photo of my desk at home, showing (L-R) RPi3, Two monitors for my PC, and on the right, the Lenovo USB monitor. The interesting thing about this setup is that I just discovered that when I plug the USB monitor into my PC, it comes up as a third screen. I can drag my mouse across all three screens! BTW, I had to clear off about a cubic yard of papers and other junk from my desk before taking this picture.

Paul, that's damned impressive and more complex than what I'm trying to achieve.

A RPi 3 costs $35 on Amazon. Just insane.
Since the parts are so damned cheap, I'm definitely doing this and probably sooner than I thought. The OpenCPN website contains complete resources for configuring everything. I'm compiling the parts list now.

One minor downside that I'm seeing, is that no matter what I do, the brain is going to be exposed to a certain amount of corrosive and damp atmosphere on the boat. I don't expect long life out of this thing.
I can extend its service life by removing it from the boat and bringing it home during the winter, and when not in use, if I don't mind the hassle. Maybe some desiccant packs would help.

I'm looking to make this simple and as painless as possible, so I want to buy the Canakit 8BG microSD card pre-loaded with NOOBS. After that, I need to download and install some Ubuntu resources and then, OpenCPN. Question: Will all of that fit onto an 8BG card? If not, I'll need to buy a larger card without NOOBS and do it the hard way. I'm not seeing any sizes listed for these software packages.

Rich,

There is a thread on Cruiser's Forum about problems installing OpenCPN on a Pi3. Check it out before you beat your head against the mast.

TheOffice wrote:Rich,

There is a thread on Cruiser's Forum about problems installing OpenCPN on a Pi3. Check it out before you beat your head against the mast.

Aw, phoo. There's always a turd in the punchbowl. Ok, I'll check it out.
I'd also like to know if the Pi3 will interface well with a DUAL GPSX150 puck.

Ajax,

We use a Pi3 as the engine in a deployable, encrypted data/video security station packed in a pelican case and used in various places, including the sandbox. Only issue we have seen is heat related. Run hard, it's a heat mill and we had to add additional heat sinks and fans to the case to prevent shutdowns and failure, exposing the device to more corrosive humidity and that lovely powdery desert sand/dust than we would like. Admittedly, we push it pretty close to its performance limits, but I'd caution against burying the Pi in a small, unventilated compartment.

LarryHoward wrote:Ajax,

We use a Pi3 as the engine in a deployable, encrypted data/video security station packed in a pelican case and used in various places, including the sandbox. Only issue we have seen is heat related. Run hard, it's a heat mill and we had to add additional heat sinks and fans to the case to prevent shutdowns and failure, exposing the device to more corrosive humidity and that lovely powdery desert sand/dust than we would like. Admittedly, we push it pretty close to its performance limits, but I'd caution against burying the Pi in a small, unventilated compartment.

Wise advice, and fortunately, that was not my plan to bury it in a locker. There is a small, wooden shelf attached to the side of the breaker panel cabinet. A whole stack of obsolete navigation equipment was mounted there, such as a SI-TEX LORAN receiver and other gadgets. I kept the shelf and intend to mount the Pi there, in a case purchased from Amazon. It includes some heat sinks. Very sheltered from water and direct sunlight but exposed well enough for ventilation. I don't think my application will push the Pi as hard as yours.

Crap, discovered a new wrinkle-

The DUAL GPS puck doesn't seem to be compatible with the Raspbian OS. I'll need to select another GPS.
It needs to be cheap, accurate and easy to integrate. (USB or on-board without being huge.)

Some of the GPS units I'm seeing are not so accurate for position and mainly for receiving timing signals from GPS, such as NTP.
I found a USB thumbdrive GPS but am concerned about its accuracy and precision. This is for navigation, after all.

I bought a cheap Dell mini computer that runs windows. Hope is to cut off the power supply and use a 12 to 19 volt transformer to run it. Not sure if it will work - Dell uses a 3rd wire on the power supply to verify proper current.

I'm using this USB GPS puck on a RPi with no problem: https://www.amazon.com/gp/product/B01174FUHU. The brand name is "Generic" (!) and I am using it as a timing source for a micro-transmitter used in radio propagation studies, but it seemed to locate my garage well enough.

The transmitter *is* the RPi, where the Pi directly generates the radio signal using the internal timing-generation hardware. It's pretty neat. Here are some blog posts I've made about this: http://wb6cxc.com/?p=5, and a presentation I made to the local ham club: http://wb6cxc.com/wp-content/uploads/2016/03/Ham-Presentation1.pdf

The one you linked says "no longer available."

I did discover this one as being specifically Pi3 compatible: https://www.amazon.com/GlobalSat-BU-353 ... Src=detail

I also found 3 good HDMI, 12v, Pi-compatible monitors, so no need to jump through all the hoops to make a USB monitor work.

Ajax wrote:The one you linked says "no longer available."

I did discover this one as being specifically Pi3 compatible: https://www.amazon.com/GlobalSat-BU-353 ... Src=detail

I also found 3 good HDMI, 12v, Pi-compatible monitors, so no need to jump through all the hoops to make a USB monitor work.

This all sounds good. Can you post a link to the HDMI monitors? I'm always interested in low-power-consumption solutions.
I've also used that GPS you found, and it works well. The chip-set they use is a good one.

Sure. From $66 into the low $100's. They are all bulkier than I would prefer, due to having integrated speakers. I knew I was going to compromise somewhere...
All 3 of these can use a straight wire to 12 volts or the little wall wart that comes with them.

https://www.amazon.com/gp/product/B073Z ... 6ORC&psc=1
https://www.amazon.com/gp/product/B01J5 ... 2Q66&psc=1
https://www.amazon.com/gp/product/B06XH ... IJM2&psc=1

or this:
https://www.amazon.com/dp/B01MR3BFVP/_e ... 0UKFMMIICK

Good point -- AFAIK the RPi will drive *any* HDMI monitor, it doesn't have to say "RPi compatible". I've got over a half-dozen RPis of various vintage, and I've just plugged them into whatever HDMI monitor I had lying around, big or small.