8v92 Digital Engine Data Conversion

[rustybucket]

Interesting project.

How would you compare this solution to that offered by Chetco?

On the engine data side, similar but somewhat different. For example, my system will handle almost an unlimited number of digital sensor inputs. Currently it will handle 32 analog inputs and can be expanded by 16's at a cost of about $20/16 inputs. I'm kinda un-clear as to how many analog/digital inputs chetco allows as their dropdown product configuration menu kinda confuses me.

I may be wrong, but it looks like you have to choose your network on the chetco. With mine, all the network protocols would be included.

My OS is linux based, chetco is windows (which was a non-starter for me with chetco). I wouldn't trust windows to watch over a rock in my yard.... but that may not be an issue for others.

My system offers satellite and cellular text messaging capability for alerts or communications.

 

[krush]

On similar topic, here's a guy that made an ardunio auto pilot: http://themarineinstallersrant.blogspot.com/2013/12/the-arduino-autopilot-that-jack-built.html

 

[rustybucket]

Figured I'd take a few mins to update this thread. Quite a bit of time has passed on this project but I'm back to it. Last week I hooked up the EGT sensors and got that data flowing to the RPi. Was really cool running the boat and being able to watch egt's on all the turbos. My port engine has always ran a few degrees warmer than stbd on the coolant reading, on EGT's it was approx 50degs warmer. Port was steady at 850ish deg and stbd was steady around 800. This was running 1850rpms. Anybody know what the warning level should be for egt on the 8v92's? Reading is being taken immediately after the turbo in the exhaust flange that connects to the turbo.

I've technically changed how I'm approaching this from a hardware standpoint. I've removed the arduinos and am using solely one rpi and mdc3008 analog to digital converters with level shifters for all my analog sensors (mainly my pressure sensors). When I get to fuel flow and tach I believe I'll have to incorporate arduinos dedicated to those functions.

I brought the boat brain system back home with me after our last trip and have been piddling with it over the Thanksgiving break and made some really good progress. Getting closer to having an actual usable product here.

I've got the brain reading all my sensors on the desk now (not all pressure sensors installed yet), temp (coolant, oil, trans oil, EGT x2 per engine) and pressures (oil, trans oil, coolant, fuel, boost).

I'm using python on the rpi to read all the sensor values. I attempted to use node.js and signalk to handle serving up everything else but fell flat on my face with them. So I reverted back to python for everything. So I've got a python web server built in the rpi using flask to help maintain a mvc programming structure as much as possible so code will be portable and fairly easily shared. Using bootstrap for the views so all the displays should very much be mobile friendly as well as on a tv or laptop.

After I finish creating the database models (hopefully today) I plan on uploading everything to git so others can poke around in it if they are interested and use any code they want.

Apologies if I got too technical in the post, sometimes it's necessary to go there to convey this stuff.

 

[madhatter1]

I am interested in this as I was just researching for an engine monitoring system. My biggest fear with 8-92's is overheat and it's the sudden ones that do the damage. My eyes can watch the gauges all day and still be looking away when something like a water pump goes.

On temp alarms there is always a threshold that when reached will cause an alarm but can be to late. Any way to have a sudden rate in rise make an alarm or pre alarm?

We run the boat slow most of the time but plan on a Key's trip next June and want to run on plane across the bay and have piece of mind.

I also like the overlay of critical sensors as a backup.

 

[krush]

Just want to put this here: https://www.thehulltruth.com/marine-electronics-forum/881525-chetco-digital-sea-gauge-g2.html

That's a guy over on THT that did digital conversion on his detroits. Lots of good info.

 

[rustybucket]

I am interested in this as I was just researching for an engine monitoring system. My biggest fear with 8-92's is overheat and it's the sudden ones that do the damage. My eyes can watch the gauges all day and still be looking away when something like a water pump goes.

On temp alarms there is always a threshold that when reached will cause an alarm but can be to late. Any way to have a sudden rate in rise make an alarm or pre alarm?

We run the boat slow most of the time but plan on a Key's trip next June and want to run on plane across the bay and have piece of mind.

I also like the overlay of critical sensors as a backup.

With the alarms, one good thing about rolling your own, or open source stuff is that you can write an alarm for anything. From my experience in an overheat situation, EGT is almost always the first parameter to climb out of spec (other than exhaust manifold temp at each port). It's almost always the first to trigger an alarm, will be out of spec far before water temp..etc.

Another pretty common engine killer is a hole in a freshwater line on the engine. The engine dumps all coolant out, the temp sensor is no longer submerged in water and will not show hot. Again here EGT will be a first alert, but even before egt coolant pressure will show a drop pretty much before any temp has a chance to rise.

I'm not discounting any commercially available system. They are pricey and rightfully so, putting this stuff together is not child's play. It takes a fair amount of technical and mechanical know-how just to design a system that is going to work.

 

[Scarlett]

Mad hatter, best thing for overheating early warning is a good old fashion flow alarm. I put them in, tells you the second you lose water flow, way before an overheat alarm sounds. Made by Aqua Alarm, simple to install, has a remote panel that can be mounted any where. I have mine inside under the dash. Only problem is if the alarm goes off I have to open the helm to see which engine the alarm is for, but that’s ok for me. John

 

[madhatter1]

Mad hatter, best thing for overheating early warning is a good old fashion flow alarm. I put them in, tells you the second you lose water flow, way before an overheat alarm sounds. Made by Aqua Alarm, simple to install, has a remote panel that can be mounted any where. I have mine inside under the dash. Only problem is if the alarm goes off I have to open the helm to see which engine the alarm is for, but that’s ok for me. John

John, that sounds like a great system to tie into rustybuckets system he is working on.

FYI to all I am a building controls guy. Wanted some home automation when building out house in 05. Everything residential was SO overthought and complicated that I wanted nothing to do with it. There was even one called HAL. HAL killed Dave in 2001 space Odyssey!! Anyway just used some leftover commercial I/O boards to have the most expensive lawn sprinkler control and Christmas light timer.


Anyway, I get why he is pursuing this. Forget bells and whistles, get it to do what we really want. Boatsb is 100% correct that in order to market it you need readily available and common sensors and threads. Not sure what the head end is but a way to save custom settings and program on a drive would go a long way twards making the head end easily replaceable. Like a computer loss its not the $, it's all the software, files, and setting you really lose. I believe Mrdeepseafisher owns a controls company so may have some input.


I volunteer for alpha and beta if needed.

 

[rustybucket]

John, that sounds like a great system to tie into rustybuckets system he is working on.

FYI to all I am a building controls guy. Wanted some home automation when building out house in 05. Everything residential was SO overthought and complicated that I wanted nothing to do with it. There was even one called HAL. HAL killed Dave in 2001 space Odyssey!! Anyway just used some leftover commercial I/O boards to have the most expensive lawn sprinkler control and Christmas light timer.


Anyway, I get why he is pursuing this. Forget bells and whistles, get it to do what we really want. Boatsb is 100% correct that in order to market it you need readily available and common sensors and threads. Not sure what the head end is but a way to save custom settings and program on a drive would go a long way twards making the head end easily replaceable. Like a computer loss its not the $, it's all the software, files, and setting you really lose. I believe Mrdeepseafisher owns a controls company so may have some input.


I volunteer for alpha and beta if needed.

Thanks for the feedback. Couple of points...

First of all, I'm not in this to make a penny. The market for this is not big enough and there are already many players in the field. To make a decent profit I'd have to charge their rates (maybe a little cheaper) but it just doesn't make sense to me. Honestly I don't really think the idea is commercially viable. The number of boats that would use this system decreases daily, it's a shrinking market. Bottom line is I'm doing this for me, and happy to share the code/instructions.

Second, the 'hard drive' for the rpi is just a micro sd card. So basically you copy that sd card, pop it into another rpi ($35) and you have a second system. I plan on carrying a backup on the boat at all times ready to plug/play it. Honestly at $35/pop you could easily carry several spares with you. That being said, I've had some of these things running for years (without being shut down) and they are still going strong. My garden sprinkler system runs off one that is located in a greenhouse open to the air/moisture...etc. 3yrs old and still kicking.

I'm not saying they are bulletproof, in the end they are an electronic device, but there are no moving parts, everything is solid state. Honestly it blows my mind that they are so readily available and so cheap. It's truly amazing how far computers have come. I do spray the units down with some type of corrosion blocker. In the past I've used T9 Boeshield but after using corrosionx on the boat recently I'm kinda eager to try it out on one. If you need to install in a VERY wet environment they can also be encased in resin or submerged in an oil bath.

All my engine sensors are ran to terminal boards in the engine room. From there a couple of cat6 cables run up to the cabin behind the tv (where I installed the boat brain). To swap cpu's I just power down, unplug 4 or 5 cables, plug everything back in and power back up.

I'm also installing a standard computer backup power battery. So when you switch from shore to gen there is no interruption, or if something happens and ac power is lost I still have several hours (10-12hrs) of operational battery. You could also wire it to the engine or gen batteries (or all of them) for backup power source using a simple voltage converter. The system only needs 5v to function and would run for days off a full size marine battery.

The code I'm writing is going to be open source under the MIT license. It is already posted on github although it is quite a ways from what I would call a beta release. Maybe by the end of dec it will be ready for public release. Once it's ready for release I'll post links to it here.

I'll be putting together somewhat of a DIY instruction on the whole project when I get done.

 

[rustybucket]

Mad hatter, best thing for overheating early warning is a good old fashion flow alarm. I put them in, tells you the second you lose water flow, way before an overheat alarm sounds. Made by Aqua Alarm, simple to install, has a remote panel that can be mounted any where. I have mine inside under the dash. Only problem is if the alarm goes off I have to open the helm to see which engine the alarm is for, but that’s ok for me. John

Where in the freshwater flow loop did you install the flow switch?

I looked at the flow alarms offered by aqua alarm and it looks like they are fairly simple flow switches. If that is indeed the case they would be very simple to integrate into my system.

I guess for situations like complete flow loss they would be great, but what about reduced flow or freshwater leak situations where the pressure drops and the system is slowly emptied. Seems like flow would continue until the reservoir is completely emptied. Flow, and pressure would be greatly reduced before flow actually stopped. Not sure at what threshold the switch triggers?

So for a total water pump failure the flow switch would be just about perfect. But that's the only situation I can think of where it would catch an issue before the temp climbed and the issue would be shown on the temp sensors.

 

[madhatter1]

I think a simple digital flow switch is all that would be needed. The operator is still responsible to watch gauges when running and make ER inspections when not. This covers reduced flow rates and leaks. The alarm system should be catching sudden events in an attempt to safely shut down before major damage. At least that's all I am looking for.

Also if exhaust gas temp is first sign of any overheating condition I wouldn't mind if I had to acknowledge this alarm if it showed up planning off. Would rather this be the most sensitive for high threshold and if possible rate of rise.

When my Cummins overheat light and sounder came on it was too late. Damage done.

 

[krush]

Another pretty common engine killer is a hole in a freshwater line on the engine. The engine dumps all coolant out, the temp sensor is no longer submerged in water and will not show hot.

In my experience, most engines have sensors mounted somewhere where even with out coolant, they will get hot and show the engine is overheating.

 

[rustybucket]

Sorry guys, forgot I had this thread going or I would have posted my update here. Apologies this is a somewhat duplicate thread of the other thread I just started. Want to keep all the info here for future readers.

Did a seatrial last sat after a full engine tuneup. Got to really test out the newest version of Yacht Brain. Not to get too technical but it takes digital sensor data from the engines (currently only temps) and broadcasts them via wifi on the boats wifi network. So any device connected to the boat's wifi can access the data by entering an ip address in their browser, so iphone, ipad, computer, smart tv...etc. We had the engine temps running on the salon tv, an ipad on the bridge and an ipad in the engine room.

Here are the gauges shown on an ipad

Here they are on the tv

The latest verion comes with some great performance increases. This was primarily accomplished by going away from a ajax based sensor polling, where the page requests sensor info from the server, the server gets the info and responds. The new paradigm uses a web sockets approach, where the main cpu is constantly polling the sensors on a loop and pushing the data out to whichever consumers are viewing. This exponentially reduced server load and speed when multiple devices were connected/running.

Before this web sockets approach after 4 or 5 devices were connected the server would become heavily loaded and drastically slow it's responses. If you added enough devices it would spike the cpu and the server would lock up. With the new architecture the number of devices that can connect is basically unlimited.

Also there is some even better news with the release of the RPI 4. The new raspberry pi has a much stronger cpu and available with up to 4gb ram. This alone is going to really push this project into something very usable and more extensible.

I've been playing with tank level sensors and analog pressure sensors and have just about ironed out all the details of implementation. Hope to start connecting the already installed pressure sensors on my next trip down. I have come full circle on analog sensors. The original plan was to use arduinos with analog inputs connected to the rpi, years ago this was not as possible as it is today. There are now libraries available to assist in having the rpi more reliably talk to the arduinos so I have now shifted away from the mcp3008's back to the arduino megas.

 

[rustybucket]

Here are a few screenshots of the tank level sensors. These tank level sensors are available on amazon and were pretty easy to integrate into the system.

The size of the 'tank' on the screen is directly proportional to the actual capacity of the tank. So if you have two fuel tanks, one 100gal and one 200gal the 100gal will be visibly smaller than the larger tank. Current version shows percentage remaining as well as gals remaining.

 

[rustybucket]

Based on feedback from the other thread from Pascal I'm also adding in amperage sensors, so we will be able to monitor AC current/draw.

 

[ageless]

Well done sir