Engine Instrumentation Project - Page 10 - PeachParts Mercedes-Benz Forum

mach4 · #**136** 12-14-2015, 12:22 AM

Now that the pcb is done and now in final test phase, and the parts and pieces needed for moving ahead with the MPG computing part of the project are not here yet, I thought it would be fun to put a little levity and creativity into the system by building a set of Steampunk-themed Gauge screens using a simulated Nixie-tube display, to go with the digital, ribbon and analog gauge sets already done.

This turned out to be a rather complex task because instead of using simple computer generated fonts or lines to display the "gauge" readings, I had to figure out a way to load individual nixie-images to represent each digit and decimal based on the gauge value at that moment.

Using miscellaneous graphic components I found on the internet I assembled a Steampunk graphic background with transparency where the nixie tube numbers would show through when loaded in the layer behind. I decided to use two display screens - one for temps and one for pressures and volts, in order to keep the nixies large enough to be representative of the real thing. The little "button" in the lower left toggles between the screens.

The image below is the mock up in Photoshop, along with a full-size nixie element image, but I've actually got most of the application running in Processing. It needs a bit more work but it will be a relatively easy task to incorporate the new displays into the main EDMS-II system by cutting and pasting the code and adding a couple control elements. I've learned more about arrays than I ever wanted to...

mach4 · #**137** 12-28-2015, 12:43 PM

My statement above regarding incorporating the Steampunk gauge screen being a relatively simple matter turned out to be another erroneous assumption - it actually took a couple days. The problem was error trapping - a bad piece of data in a malformed data packet was ignored by the previous screens but crashed the system in Steampunk. But now it's working flawlessly and is one of my favorite screens.

mach4 · #**138** 12-28-2015, 01:03 PM

I've been researching the idea of buying a mini mill for the home shop and in the course of doing the research stumbled on an Arduino-Android-Bluetooth application very similar to my EDMS project. The project is Touch DRO. A common upgrade to a standard mini mill is the addition of a DRO (Digital Read Out) which provides real time digital positioning of the cutting tool in all axis. Like my EDMS system, Touch DRO uses a series of sensors (digital distances and soon RPM) connected to an Arduino system for data collection and processing. The Arduino sends the data to an Android tablet wirelessly over Bluetooth where the information is presented in an Android app.

Unlike my little project Touch DRO was designed and written by a Java pro and is really professional. It was really encouraging to find another application using the same fundamental Arduino-Android-Bluetooth architecture to design a useful application. He's even designed a custom PCB for the Arduino end like I did.

mannys9130 · #**139** 01-06-2016, 11:30 PM

I really like that nixie tube readout. Very cool looking.

mach4 · #**140** 01-28-2016, 05:45 PM

No updates for quite awhile as the system has been working really well and I've been awaiting parts for the next phase, the MPG computer. The original Chinese fuel flow transducer I ordered was a complete waste and I ordered a more promising one to test - as the below invoice shows that was on Nov 1st and it arrived today, just a couple days short of 3 months! (Good thing I didn't need it urgently) A quick inspection shows that this unit has promise to be a real solution.

Looks like I'll be making a trip to the junk yard soon to see if I can source a float bowl. Last time out there I didn't see any, so may need to explore different options.

I've also got the ammeter module to wire in and make the appropriate code modifications.