You may have seen my first effort at a small configurable dashboard for MS2. I have it installed in both my MS cars and am pretty happy with the way it works. Nice to see the info whenever I drive, without having to lug a laptop around.
More for the intellectual exercise than any good reason, I'm now planning to upgrade it to a small TFT LCD colour display. To start with, I've been working with a $5 1.8" 128x160 pixel display. Might be a bit on the small side, so I've got a 2.8" 240x320 display on the way ($7 -- talk about lashing out!). It's been fun writing the graphics primitives for it, and performance looks pretty good. I am about to start on implementing the actual gauges and would like to hear if anyone has any suggestions.
I'll start with a mock-up image of one configuration, then explain the concepts and gauges.
Assuming you've got a modern monitor, that tiny thing is about life size. Notionally there are 8 rows of 2 columns of slots. A gauge can occupy one or more slots. In the picture:
- the two gauges at the top are simple numerics. Like all but one of the other gauges they only update at intervals (e.g. 1 sec) with your choice of mean, min, max, or last sample.
- Next down is a simulated green/orange/red LED bar graph which would typically be used for RPM. It occupies two slots and is updated every poll (i.e. 16 times per second).
- Next is a range gauge, occupying 2x2 slots, showing the range of recent samples in orange, the mean in white, optional 'tick' marks for the ideal value, and reporting the mean in text at the right. AFR and PW might be good here.
- The last two are instances of the same simple gauge occupying 2x2 slots with configurable blue-black-red transition points. Not bad for things that don't vary much like CLT or VBatt. Was thinking of adding a warning blue[black]red LED to it as an extra alert when the needle is straying out of the happy range.
Another sort of gauge I might do is a rolling history. Probably 4 slots, drawing a pixel or two for each sample, a bit like MegaLogViewer, which might let you look back in time a few seconds when something strange happens.
Another would be simple boolean lights like TunerStudio has for WUE, TPSAccel, etc.
These displays include an SD card slot behind them. It is tempting to write everything sampled to an SD card. Two concerns though: 1. How to mount the display neatly while still having access to the slot. 2. Potential performance impact of the extra SPI bus traffic. Also, since the MSP430 only has 512 bytes of RAM, I can't write a FAT32 compatible file system, just raw blocks.
Like the first one, I have no intention of producing or marketing this, It's just for my ongoing learning and interest. But I would appreciate any gauge suggestions, and will happily share the completed schematics and code if anybody wants to build one for themselves (only one person took me up on this with the earlier version, and I never heard how he got on with it).
Have fun,
Rob.