Project Ideas for ECR

[Darryl&Rita]

What's the advantage to Particle, vs. Raspberry vs. Arduino? Just curiosity asking.

[Jim Gell]

David,

 

I would like to build something with a Particle microcontroller for the educational value. So any project that would help me learn basics that I can apply to something custom that I decide to try later may be best for me.

 

I am really looking forward to this project, whatever it is. Thanks!

 

Jim

[Nuke-E]

What's the advantage to Particle, vs. Raspberry vs. Arduino? Just curiosity asking.

 

The simplest of the three is the Arduino--it's a microcontroller motherboard based around an ATMega processor. It's got a few hundred KB of memory, a USB connection, and digital and analog I/O ports. It's best suited for simple tasks, especially where real-time response is needed. If you needed to turn on a light when a sensor showed the humidity was above some level for more than 5 minutes, Ardunio's the easy way to go.

 

The Raspberri Pi (and a number of others, like the BeagleBone Black) is a general purpose computer that just happens to have a few serviceable I/O ports on it. They're running Linux in some form, have video outputs, a USB host controller, port for a dedicated camera, audio, ethernet, and an SD card slot. Basically, add a display and keyboard/mouse, and it'll do just about everything your laptop will, albeit with less computing power (and less power consumption too).

 

The Particle could be thought of as a wirelessly internet-connected Arduino (and in terms of physical size, closer to an Arduino Nano). You can connect to it via USB for programming just like the Arduino, but it's really meant for use tied to a wireless network. Instead of having to unhook all kinds of stuff from your breadboard to move to where you can connect a computer to fix a bug, you can both program it and interface with your program via their servers (and while it takes a little more effort, you can also host your own version of their server stuff).

[whatsnext]

I picked up a dual remote tank reading kit at the Tampa RV show. A couple of magnetic sensors on the bottom of the tanks, programmed to an LED readout in the trailer. The name of it escapes me but when I return next week, I can send you the info. It seems to work fine.

That sounds great. I have a Seelevel monitor system and it has a readout for LPG but DRV does not install a sending unit. It would be nice to see how much I have remaining.

[NTPA Announcer]

HUH..... The only thing I got out of that was Arduino bread with Raspberri Pi Jam on a Particle board.... I guess I got a lot of book learnin to do at the ECR......

 

Just kidding, this is going to be a lot of fun and very informative too !!

[Nuke-E]

I could see the possible range of outcomes spanning everything from fried stuff to everyone populating a shared Google spreadsheet and comparing who's most full of $#!~. (The Google spreadsheet bit isn't an exaggeration--logging there requires only a few lines of code, and the device is already online!)

 

My goal is to have something that's simple enough for the true novice, but still interesting for someone with lots of experience with this stuff--a challenge for sure, but that's the goal anyway.

 

Today I spent a little bit of time putting pressure sensors on my waste tanks, and configured one of the microcontrollers to read one of them. I've had a similar setup on a different board previously, but this setup is working toward what we might do in the seminar. Of course, when drilling into black and grey plumbing, you'd really like the tanks to be empty, and I was getting in there today to replace a leaky black tank valve anyway.

 

You can see there's really not much to the hardware, and the code took no more than 5 minutes--roughly 10 lines or so. Now it doesn't do much yet--it's just blinking an LED on the board at a speed proportional to the sensor reading. Bottom line is that no one should be afraid to participate.

 

[rdickinson]

That sounds great. I have a Seelevel monitor system and it has a readout for LPG but DRV does not install a sending unit. It would be nice to see how much I have remaining.

I would liken it to the grey and black tank monitors. A vertical line of LED's. The system sends a pulse every 30 seconds and stops by the appropriate LED light indicate fill level. A push or momentary switch to activate it.

 

I looked thru the Tampa exhibitors but not able to find reference to this particular item. I'll get it to you by the end of next week after I get back to FL.

[whatsnext]

Dave-

I am wondering if this could be programmed to dump the tanks automatically under certain conditions... Black first then 1 min later the gray. That would be cool!

David

[Hewhoknowslittle]

Dave-

I am wondering if this could be programmed to dump the tanks automatically under certain conditions... Black first then 1 min later the gray. That would be cool!

David

That would be cool!!

[Darryl&Rita]

Ask me why no sewage plant uses pressure Tx's exposed to process. C'mon, ask.

[Hewhoknowslittle]

Ask me why no sewage plant uses pressure Tx's exposed to process. C'mon, ask.

 

Ok I will bite, why?

 

Roger

[Darryl&Rita]

 

Ok I will bite, why?

 

Roger

Residue.

[Alie&Jim's Carrilite]

Residue.

Under pressure?

[Darryl&Rita]

Under pressure?

Pushes it further into places it won't flush out. The only way to use a pressure Tx in this application, is sensing pressure on a bubbler tube. This would require constant air supply, which few RV's have. Not for me.

[Nuke-E]

Sure. I have no good idea how long it will really read well on the waste tanks, but I can't imagine it's going to be any worse than the sensors screwed in to the tank from the factory. In my case, the waste tanks are practically surrounded by steel, so the externally-mounted capacitive sensors (e.g. SeeLevel) are no good.

 

And Roger, don't get any ideas about programming it to dump automatically when someone walks by. ;-)

[HERO Maker]

Dave, I think Roger might consider it while he was on the road, and that Sweet Old Boy next to him was just playing games. That might stop them pretty quick!

[Darryl&Rita]

Sure. I have no good idea how long it will really read well on the waste tanks, but I can't imagine it's going to be any worse than the sensors screwed in to the tank from the factory. In my case, the waste tanks are practically surrounded by steel, so the externally-mounted capacitive sensors (e.g. SeeLevel) are no good.

 

Big problem with alternate level measurement in an RV, aside from the residue, is the tank shape. Thy're usually fairly shallow, and wide. This leads to a fairly large change in volume needed to cause a measurable change in level. See-Level are probably the best available, right now, for this market. In an industrial install, I've used both radar and capacitance-in-process with good results, but they're both a little rich for the RV market. I haven't dug into the Particle spec's, but I'm assuming analog input is either 1-5 v or 4-20 mA. In this case, industrial sensors start to become price competitive.

 

Edit to add: In the installation you're looking at, I'd mount the sensor on top of a dead leg "T'd" off the dump line. The "water" will trap a dead air space in the T, and your sensor will last longer.

 

Another edit: Here's an EBay link to an ultrasonic level Tx for an Arduino. Not sure what the accuracy is, but they're claiming a range of 2-400 cm.

[Nuke-E]

I bought fittings to T off of the main drain lines, but when I got back to the RV couldn't find the 1/2" pipe tap I thought I had. So I'm considering the current setup experimental--if it works, great, if not, I'll have to come up with something better.

 

I have one of the ultrasonic sensors like in the link--it's a fun toy, but I'm not sure how you'd mount that inside the tank and protect it. The 16-bit analog inputs on the particle boards are 3.3V range, and with my tanks and the 5 psi sensors I have that gets me a little more than 600 steps between empty and full. Considering that the stock black tank sensor only reads "almost full" or "full", I'm hoping it's a substantial improvement!

[rdickinson]

I would liken it to the grey and black tank monitors. A vertical line of LED's. The system sends a pulse every 30 seconds and stops by the appropriate LED light indicate fill level. A push or momentary switch to activate it.

 

I looked thru the Tampa exhibitors but not able to find reference to this particular item. I'll get it to you by the end of next week after I get back to FL.

www.mopeka.com

 

Dave 772 321 8410

[Jim & Wilma]

Interesting Roger. The website is kinda short on details so here's some additional information Google pulled up:

 

RV-Dreams chat

PPLMotorhomes video

[Star Dreamer]

Is there a shopping list for class supplies and tools that we will need to bring for the project?

 

Dave

[Nuke-E]

Dave,

 

I'm definitely going to round up the little stuff (e.g. resistors). When it gets a little closer, I'm going to try to get a head count and order the microcontrollers. But if you want to get a head start, pick up a Particle Photon ($19, or the kit for $29 with a breadboard). They're quick to ship/deliver, so there's plenty of time to get one, connect to it, and play with a few of the example programs (blinking an LED, as an example).

 

I'm going to bring a few pressure transducers to demonstrate that part, but since they're about $30, I'm going to also have some potentiometers so that those who want to learn but not spend as much can still participate. The biggest challenge (which is helped by getting a controller in advance) is "claiming" the device. There's a phone app (or alternate USB & computer method) for registering it wirelessly, but we'll have to make sure we don't have a bunch of people doing it at once, or we're guaranteed to have one person flashing code to another person's controller, which would make for some real fun troubleshooting!

 

I'll try to post a single-page shopping list and "getting started" how-to sometime this week. The tank monitoring seems to have a good bit of interest, and is probably the simplest to set up, so that's the direction I'm headed.