Scott T

I'm building a wide-band O2 board. Would it be possible to use an analog voltmeter to display the output? If so, one could make a replacement bezel displaying the actual A/F ratio. It would be a "dedicated" voltmeter after that, but what the heck, they're cheap.

JPrevost

Yes it's a standard 0-5v output. I would use a voltmeter/multimeter to verify things are working but I wouldn't use it for any tuning. Not sure how good you are at doing math in your head but I can't think that fast in 13 seconds
You could hook up an oscilliscope so that you can actually SEE a nice plot. The wideband display on www.diy-wb.com is pretty simple. I'd use that since it'll show you AFR and not volts.

Grumpy

It would be about useless.
You need something that reacts fast enough to see what's going on. Bruce Roe's LED display is an excellent monitor. Any readout that has characters to read is going to be WAYYYY to slow to see the AE, DFCO, stuff. Getting the AE stuff CORRECT makes all the difference for drivibility.

yellow73bb

I think Scott's idea is to use an analog meter not a digital one. Then, you could print out a legend to put behind the meter that read out in AFR. That would be as quick as an LED bar graph (if you use a properly dampened meter -- shouldn't be a problem), and would be like looking at your tach. I think it's a great idea. Scott, let me know when you get it working and maybe I'll have my wb board built by then.

Grumpy

OK, if you think so.
But, I'm only commenting from having spent a couple years using one.

If you just want to get a rough idea of WOT, fine. But, getting the AE stuff correct just makes for such better drivibility.

JPrevost

Bruce, you think tuning your motor was tricky. You should see what we've been trying to do with our little 600cc Honda F4i motor. Breathing through a 20mm restrictor and having super low resolution tuning tables (every 1000rpm) makes for a LOT of work. If our AFRs are off by one point the motor will literally sound and act like it's on crack. 13.8 to 13.4 seems to give us the most stable sounding motor. With the dyno we can hold the engine at any RPM and adjust timing and fuel from the EGT, WB o2, and actual torque. I don't know how the team ever tuned without a wideband, it really just boggles the mind.

MonteCarSlow

Bruce,

I have new software for the AVR based LCD display board. I would like to submit my source files so that it can be added to the diy-wb.com website. Who do I need to get in contact with to do this?

changes to original AVR lcd display software:
- rewritten in C
- kept 10bit adc resolution instead of down-grading to 8bit
- 2x24 LCD instead of 2x16
- adc values converted to volts
- bargraph and AFR no longer use ascii table lookup
- AFR is found using linear interpolation of the Vout table
- bargraph is drawn using math
- sensor warmup mode and low battery input warnings now have
hysterises(sp?) in them

Ernst denBroeder

Grumpy

You got your email address hiden.....

Email me at BPLECAN@WOH.RR.COM