Multi-function engine monitor gauge

[thebuildist]

Cut the grass today with the Case 224 with gadget. Hydraulic Oil temperature was at 70F before I started the tractor. Outside air temperature was 78F. Hydraulic Oil temperature was at 130F when I finished. Idled her down, blew grass off and backed into the garage, oil temp was 119F.

There now, a little ramble.
Have a good up coming week gentlemen.

Noel

Oh, had me Case hat on too,

Thank you, Noel. This kind of data is great for choosing a baseline for what temp is "normal" and what is "abnormal".

Bob

[thebuildist]

Just a little update on the overall progress:

I've discovered through a lot of reading and experimenting that driving more than 2 or 3 RGB LED's from an Arduino is trickier than you might assume. The Arduino itself has enough onboard amperage to drive up to about 3 LED lights. But after that you really need to power the lights by a separate light source and turn them on and off using a transistor (mosfet), controlled by signals from the Arduino. BUT there's a problem: To get an RGB led to light a certain color, you send it timed pulses of electricity ("pulse width modulation"), which the Arduino can do. But mosfets can't put out PWM. They're a little more "clunky", either "on" or "off", you can't really do variable modulation.

THEREFORE either you need a purpose-specific RGB LED driver, which is designed to power however many RGB LED's you want and get its control signals from an Arduino, or you get special RGB LED's that have their own driver circuitry built into them.

DUE to the chip shortage currently going on, RGB LED driver boards are scarce and expensive. Like $20 expensive. Ain't nobody got time for that.

But what I did find is a little 2" diameter ring of LED lights that each have their own little addressable driver circuitry. It was about $10. So you power the ring from a separate source and use the Arduino to signal to each bulb what to do. So once it gets here, I'm pretty sure I can cut off the LED's that I don't need, and just embed the remaining arc of LED lights across the top of the gauge face, and very easily control them as desired.

So I'm waiting for that to arrive from China, so progress on this is on hold until then.

And I've got other things I'm working on right now anyway...

Bob

[Eugen]

Just to set the record straight, a mosfet is exactly right for power pwm control. But why complicate yourself when you can get a board that just does it?

[MattA]

Just to set the record straight, a mosfet is exactly right for power pwm control. But why complicate yourself when you can get a board that just does it?

Yes mosfets are used every day with PWM control. PWM is used in devices like power supplies and inverters. Maybe we misunderstood Bob?

Bob- I can give you the part number for a 32mA driver IC I use at work to drive LEDs and various optically drive gate drivers. If your using FETs be sure to get a logic level controlled FET.

[Eugen]

I probably misunderstood, sorry!

[thebuildist]

No, I'm sure you're right. All I know is that when I run it on a simulator I don't ever get the correct colors. When I started digging into it I found people saying that you need to use a driver in order to modulate the color control properly.

I'm a rank amateur in electronics, if anyone knows better and can point me in the right direction, I'll gratefully accept the help. I need to be able to control the color of RGB LED's via mosfets, and I need to address the scarcity of control pins on the arduino. I can't afford to devote 7 pins for 7 LED's.

I presume that means using shift registers or something to that effect.

Of course, once the led ring comes in, assuming it's the correct physical dimensions, it will solve both my lack of understanding and the Arduino's lack of pins, because it's intended to be externally powered, and is controlled using a single pin.

But I'm all ears for advice.

Bob

[DavidBarkey]

@thebuildist But what I did find is a little 2" diameter ring of LED lights that each have their own little addressable driver circuitry. It was about $10. So you power the ring from a separate source and use the Arduino to signal to each bulb what to do. So once it gets here, I'm pretty sure I can cut off the LED's that I don't need, and just embed the remaining arc of LED lights across the top of the gauge face, and very easily control them as desired.
Quote.
Bob , instead of cutting off the lower unwanted LEDs. why not assign them other duties like idiot lights to direct you to change pages when something goes out of range simple oil pressure switch to turn one one when drop below 5-10 psi . And a simple temp switch when you break say 200 - 225 F in the engine oil and the hydra oil . One to turn on when not charging . Just need little symbols to identify each . Maybe the one beside each of these (if enough) to light up when you are on that page . That is the one thing I struggled with when using them multi-gauge is know what page I am on . That is why I have a gauge pack in Frankie.

[thebuildist]

Dave, that's a GREAT idea. I'll see if I can do that very thing.

I think I need to physically separate the "extra" led's from the arc of the red/yellow/green "range" led's, simply because it'll be such a challenge to label different lights that are only a few millimeters apart. And I want the readability of having the gauge needle "all by itself", just for instant clarity.

But I can relocate those lights somewhere nearby, perhaps across the bottom of the gauge or something, and do what you're suggesting.

Thanks.

Bob

[propane1]

Another grass cutting with the 224 and gadget. Outside air temp 75F. Oil temp in tractor 70F, before start up. All grass blown off. Oil temp was 125F at the end of grass cutting. Was down to 113F by time I let her run around 1800 rpm while I was blowing the grass off. So then when I shut off the engine, I thought I’d turn the gadget back on a see if the oil temp would rise from thermal heat with out the cooling system on. And it did not rise, it kept dropping. So that’s good.
I figure now that I have a idea what it’s going to run at, on an average day. If it got over 140F I’d start looking for a problem. Thanks for reading, this will be the last post from me on my findings. I don’t think things will change much now. I might post once this winter when I’m throwing you know what, to see what the temps are. Just for the heck of it.

Have a good day gentlemen.

Noel

[thebuildist]

Another grass cutting with the 224 and gadget. Outside air temp 75F. Oil temp in tractor 70F, before start up. All grass blown off. Oil temp was 125F at the end of grass cutting. Was down to 113F by time I let her run around 1800 rpm while I was blowing the grass off. So then when I shut off the engine, I thought I’d turn the gadget back on a see if the oil temp would rise from thermal heat with out the cooling system on. And it did not rise, it kept dropping. So that’s good.
I figure now that I have a idea what it’s going to run at, on an average day. If it got over 140F I’d start looking for a problem. Thanks for reading, this will be the last post from me on my findings. I don’t think things will change much now. I might post once this winter when I’m throwing you know what, to see what the temps are. Just for the heck of it.

Have a good day gentlemen.

Noel

Thanks again for taking the time to give us accurate data. I can't imagine finding a better estimate of "normal" range that what you've provided.

Bob