New alternative to the ScanGauge

Thanks for the offer, but a bunch of logs without corresponding data would be almost useless. FYI: All you need to log is a CANUSB or equivalent.

 

The microcontroller has a limited amount of flash, but the trip data can definitely be stored. I do not yet do this however.

This could be done by adding more external memory. I think I'd implement this via a SD card. Personally I don't have this need, I usually just hook up the PC if I want to store lots of data. I'm trying to keep the hardware simple (read: low-cost), but if there is enough interest we could add this.

BMS is my Battery Management System. It's explained in my PHEV post. It has nothing to do with reprogramming. The PC interface is standard USB, it would only take an application to reprogram it.

This is interesting. Right now I have an indicator that shows when the Engine is in Closed loop. There might well be information on the bus to indicate this, but I haven't found it (nor have I looked for it). Of course, we do pretty much know what all the requirements for each stage are, and since we can read those it should be an easy matter to determine even if we can't find an existing "stage" parameter.

I appreciate the offer. I will let everyone here know when I have something that we are ready to test. I will not send anything out that demands tricky assembly, don't worry.

 

I have a Trademark pending on "PRIUSCAN", so you can call it that if you like!

My existing prototype (in the picture) is about 4" x 2" (10 x 5 cm) with a 20 character x 4 line display area of about 3" x 1" (7.6 x 2.5 cm). I'm likely going to switch to a larger graphic-capable display which has 192 x 64 pixels, which is about 2x the resolution. It's display area is 4" x 2.5" (5 x 3.8 cm). Both are monochrome displays that generate high-contrast white characters on a nice blue background. They also both use an LED backlight that's fully dimmable. For reference, the ScanGauge uses a 16 x 2 character (80 x 16 pixels) display.

I've got the rotary encoder "knob" mounted on the side, but I'm not sure if this makes sense. I do love the encoder compared to buttons though!

I actually had mine in a case (off the shelf), but the case simply made it bulky, and it wouldn't fit nicely over my mirror like it does now. I now have just the bare guts, but I've taped it all up with black gaffer's tape. It actually looks nicer this way than it did with the case, I was surprised!

 

I'm currently just using the built-in PCA (programmable counter array) to generate tones of any desired frequency, and that's driving a tiny speaker much like cell phones use for ringers. While I could combine the PCA's to make more complex tones, it's probably not sufficient to make that "Prius Noise". You'd also have to add an amplifier and external speaker.

If I was going to tackle that, I would do it as a separate unit. Use a microcontroller with a design more suited for audio, or at least add an external audio DAC. The sound in that video doesn't sound complex at all, it seems like it's only a few frequencies with at 2 of them being close so there's a beat frequency. (can someone analyze it?)

I think even with my limited audio experience, I could come up with a cooler sound though. It also doesn't seem to track the speed with much precision. There is high-resolution speed data on the CAN bus that could make this work better.

But this is a topic for post (and time!)

(Thanks for the Video BTW!)

 

Hi Mitch, I'll go ahead and reply to this in the other PHEV thread.

 

Maybe we should measure driver pressure and oil mood?

 

Unfortunately due to the thriving business of Chinese knockoffs, I doubt I'd be able to share the source code (at least initially) and not be out of business. Developing code like this takes a solid time investment, and really, it's the largest part of this project. Giving it away free would likely make it impossible to continue to devote as much future time to the Prius as I'd like.

I've always been an open-source guy and I am a generous person who shares my time time and knowledge freely, but sadly, there are people always waiting in the wings to exploit that.

What I can do to offset this is make the thing highly customizable and easy to apply firmware updates in the field.

 

I suppose external outputs could be made available to drive LEDs and such, but I've got to really try to keep the hardware simple, and focus on the software. This will keep it manageable. If we allow feature-creep, you'll never see a finished device.

In fact, I can easily spend the bulk of my free time just answering questions here and not have any time to work on it!