Monday, May 14, 2012

Strange Damage to front badge

The other day , as I was looking over my pollen covered car ( my car needs a wash and detail BAD!) I found something interesting had happened to my front Pontiac Logo. Eventhough I had replaced the rear one with the TSS aluminum one in black (yes I've been running with mismatched badges, both in shape AND color - the OCD horror! lol) , I had never put the front one on since I was saving it for that 'vaporware' new bumper project ;) So I'm looking at my logo and for some reason it seems a little less red than normal: Somehow the original red-plastic has broken and I am missing huge chunks!

The Strange thing is that looking at the bumper I don't see any other dings etc that would indicate someone backed into me. I'm not quite sure what to make of it, besides that perhaps a car-wash somehow managed to do this with some high pressure water...Then again 'weird' damage on top my now 3 rockchips, seems to be my thing.. So it looks like I'll have to either get a new front badge, or put the new TSS one on. Of course the one I have had on the back for the last few years is showing some major wear too, and I need to contact Jaison@TSS about a good way to clean this up.

You can tell the clear has begun to peel in several spots. Also when I ordered my badges I went with the black because I figured it would look good on my black car. The more I look at my red pontiac badge up front though, the more I really like that Red little accent on a whole black car. It really ties in my Red Fender "GTS" Badges etc. I may just order a red version of the TSS badge and slap that on and redo the rear one to match. It also makes me wonder about a brake upgrade. I really can't decide between Black, like VegasNate has on his car, or Red. Not that it matters right now being flat-broke, but it's fun to plan ;)

As far as the radio logo stuff - there's been some interesting developments. Also for the ELM329 device I'm actually waiting on several PCBs I had made for the SWCan Board. I did a batch of a dozen or so because of the cost, so if the design is proven to work after the first one, I could probably sell some (thinking either as a bare PCB with BOM list, a PCB with components or already pre-soldered in case you don't feel like dealing with small SMD components). If anyone is interested in buying some once they are done, let me know!

Sunday, May 6, 2012

Custom Hi-Speed CAN/ SWCAN Scanner (ELM329)

So after modifying an existing ELM327 Clone I read about the new ELM329 chip - it is specifically targeted for CAN Networks and sounded like a very interesting option. When I did some more research on it I ran across a post over on where 'reinoso' showed off a board he developed. The cool thing about it was that he added a switching mechanism to select between Hi-Speed CAN or Single-Wire Can.

I figured it would be a fun exercise to try to design something similar. The ELM329 Datasheet provides the basic reference schematic so it was just a matter to add the switching mechanism and draw up the new schematic and PCB. Initially I started out in Altium Designer (which is GREAT) because Eagle is just too... shall we say 'quirky' (though some call it 'female' because it's illogical lol). Being a software engineer by trade, it has too many 'WTF were they thinking' issues - yes you can get used to them, but the fact they're even there just bugs me ;) . However as I got a little deeper into it I figured that if I ever wanted to release the schematic/pcb etc for public use, not too many people have Altium Designer, and thus would not be able to use it. so begrudgingly I went back to Eagle.

My goal for right now was to at least get the schematic going properly and then for a first build have the PCB fit inside the generic ELM327 device box I already have. I measured it's PCB and based my layout on that so that it would be a drop-in replacement. I kept both connectors (USB (4-pin) & OBD (original 8-pin) ) in the same place to make it as seamless a swap as possible.

For the actual soldering process I wanted to try out the reflow toaster over method, so for the main passive components I felt fine going to 0805 component size (yes I've heard of people doing 06 or 04 etc without problems, but I'm not the steadiest hand). The ELM329 comes in a SOIC28 (or DIP package) which is relatively large. Also for the USB connectivity I went with the SiLabs CP2102 - it only needs a few extra components, but it's definitely not a hand solder component being a 28-VFQFN component.

Top View of PCB
Bottom View of Board showing Both Can Transceivers and switch IC

Another Angle of the Top
I Made the above 3d previews using the EagleUp Plugin for Sketchup.Not all components were available so I had to get creative in making some of them myself (e.g. the 4 pin header block) & the MSOP 10 package for the switch (IC2) on the bottom.

Now it's off to finding a decent PCB Manufacturer who can build a few of these boards for a decent price.

Of course it will be interesting to apply this to the upcoming STN1117 chip and minimize the footprint even more.