Tank Monitor replacement - digital

[RichHog]

Very nice work. sign me up!

[Zeppelinium]

Per the briefing at the Restoration Rally last weekend, the monitor and the rest of the panel are modular, so it can take any shape (within limits) that fit your location and design objective.

Here's four examples of just the monitor and the pump switch.





The items in BLUE (the LEDs) and the four small mounting screw circles are established by the PC Board and cannot be moved in relation to each other. However, you can have some or all of the LEDs, per the number of sensors you have (or will have), and two or three tanks. The other option that is shown is you can eliminate the bottom row of LEDs (they are on all the time the monitor is on--I hated the old system where if the tank was empty, no lights came on at all). You can move the BLACK text and the RED switches and text around where ever you want them. You can add other text, and even a label like "My Special Cool Ambassador Monitor." You can eliminate the pump indicator (or make it constant, eg, non-flashing) and/or the pump switch. You can also eliminate the bright/dim option. I've found that I generally like the LEDs on dim and the pump flasher on bright. If you set up your panel that way, you can save some parts and a $5 switch.

You can put the volt and amp meters above, below, or to the side, if you want them.

You can add a clock or a temperature device of your own choosing, but you have to figure out the window dimensions and placement, totally. And how you're going to mount them/it mechanically.

The plastic front plate can be used (carefully) as a drilling and filing template--the laser cuts out the holes, but only removes the top color layer for the text.

It appears that we have 4-5 interested parties from the Rally. However, all interested parties must PM me an state their intentions and the options they want in their panel. I'll cooperate with each person to get the panel design right. The PC Board is the same for all, you just don't put in all the parts.

Zep

[mello mike]

A pic of Roger holding his new monitor panel (this was just taken at the Restoration Rally in Albuquerque).

[Zeppelinium]

If anyone wants the panel design in Corel, CAD (DXF), CAD (DWG), or Autosketch (SKF), drop me a line using regular email and I'll send them to you. You can use these files as a basis for your own design, or leave the layout the same and just change the text labels.

Zep

[Scott CoBen]

I have a 1993 Excella and the tank monitor says the tanks are part way full when they are empty. The manual says I have a bad panel. Is that the problem and if so where can I get a replacement?

Thanks

[Zeppelinium]

Scott, the monitors changed over the years. I don't know how yours worked. The early 70s used four wires (or so, depending on the tank) to light the light bulbs. In the mid 70s that changed to two wires and some resistors, but it was still a pretty simple conductive measurement device. Later, the system measured pressure.

You can buy a new pressure measuring system and install it, since the voltage sent by the transducer can use the same wires that either system (pressure or conductance) used. I don't think the older systems are supported by Airstream any longer.

I don't supply units, just the poop for you to make it yourself.
Zep

[Zeppelinium]

I have "discovered" a very easy to program microprocessor product from Arduino that can provide a complete monitor system in one small $12 PCB and a small additional PCB to hold the LED level indicators.

This Arduino device has 8 analog inputs, so it can do a lot more than just the tank levels. More to come.

I enjoyed tinkering with the dedicated logic of the monitor described in this thread, but adjusting the resistors to match the input voltages was a true pain and took a lot more time that just changing the voltage levels in software in the Arduino.

If you're interested in replacing your tank monitor, look for a future post titled "Arduino Tank Monitor". This one will be a piece of cake, believe me, compared to using dedicated 7400 logic chips. Not to mention easier to build and cheaper.

Zep

PS--the Arduino can monitor the fresh tank for freezing, watch the battery voltage and current, and record indoor and outdoor temperatures. More on that later, too.

[ROBERT CROSS]

Subscribed!!!!

Our AS monitors haven't krapped yet...but I have some boat applications in mind.

Bob

[Zeppelinium]

This is the prototype of the digital tank monitor. Note that it has battery volts and amps at the top and tank temperatures for each tank. The full thread on this little beauty might be ready by the New Year--watch for it.

Total cost: cpu card $10, display $20, temperature sensors $6, current sensor $4--$38.
Z

[wxbuoy]

Awesome!

[PharmGeek]

Would be cool to have info sync to my iPhone in real time via Bluetooth or wifi

[Silverflames]

Originally Posted by Zeppelinium

This is the prototype of the digital tank monitor. Note that it has battery volts and amps at the top and tank temperatures for each tank. The full thread on this little beauty might be ready by the New Year--watch for it.

Total cost: cpu card $10, display $20, temperature sensors $6, current sensor $4--$38.
Z

I would buy one!!

[cwf]

Does this mean u use the existing tank probes?

[cwf]

Originally Posted by PharmGeek

Would be cool to have info sync to my iPhone in real time via Bluetooth or wifi

Cool idea

[Zeppelinium]

It could be done, but since I only have a [stupid] flip phone I could never test the app. The Arduino microprocessor family has Bluetooth interface cards.

Z

[Aviator]

That would be cool feature.

[wxbuoy]

Originally Posted by Zeppelinium

It could be done, but since I only have a [stupid] flip phone I could never test the app. The Arduino microprocessor family has Bluetooth interface cards.

Z

You are far smarter then those of us who have to carry the smart phones for work!

[Chillpoints]

That looks wonderful. I have the '92 version that still works as long as all the contacts are clean. When it is very humid they seem to jump around. The black tank is always susceptible to trash causing it to read full even when empty. I would like to see more about the pressure system for the fresh tank. It is always confusing when the indicators are at set points ie. If you are gallon less than full you are at 3/4 of a tank until it jumps to 1/2. Then I have to remember hpw many gal is full to calculate wha is left. In a perfict world it would count down from total gallons 40,39,38,37....
Likewise the battery is good fair weak. It can b weak and you can turn off a light and it goes back to good. It would be wonderful to know numbers for that. Not to mention would love the temp. I would put one sensor outside and one in my freezer. I don't need to know if I am warm or cold, but my beer in the frige is another story. I look forward to hearing more.

[Zeppelinium]

Please go to this thread for continuing discussion/development of the microprocessor based monitor.

http://www.airforums.com/forums/f443...ml#post1383992

Zep

[Zeppelinium]

BARTS, what happened to your post that recommended the Raspberry Pi and Bluetooth? It used to be up there before post #55. I did go check out the Pi and it's a very powerful processor card. I'll probably adopt it for other uses where there is an existing WAN, like at the new house.

Anyway, the reason I'm back on this old thread is that I stumbled on a pile of PCBs for this old design. I recall there is one error on the boards where you have to cut the power traces for the pump and maybe one other place in order to get it work right. Anyone want them, they are up for grabs (4 total). Three of them have the resistor network on the edge for converting the old 4-wire monitor system to the newer (only 35 years old) system.

Zep