SLC oem from 14point7

[AndreyB]

http://www.14point7.com/products/slc-oem

SLC OEM is a low-cost, miniature Wideband O2 Controller suitable for integration into your own products/projects. It is a complete Wideband O2 Controller requiring only an external 5V power supply.

SLC OEM utilizes the BOSCH LSU 4.2 Wideband O2 sensor to achieve 0.01 Lambda accuracy without the need for calibration.

SLC OEM provides an analog linear output and digital I2C communications, upto 32 SLC OEMs can operate on a single I2C bus.

With $40 a piece and $350 for qty 10, I think that's a perfect option for us rusEfi right now!

[kb1gtt]

This fellow from 14point7 seems to have done a bunch of testing with lab gasses to check a variety of calibration items. I believe it to be a quality low cost product that should be good for rusEFI. I will try to look over the published schematics, manuals, ect to see what would be needed to add this to a design. I'm guessing at min a KICAD footprint, perhaps some bulk caps or regulator or something like that. I don't think it would be very hard to find a way to add that module.

[AndreyB]

I've got the unit, and I have a 4.2 sensor. Now I am trying to wire those two together.

There is that mysterious green wire which I do not understand:


See also http://wbo2.com/cable/lsuconns.htm


In my case the 6 pin connector is already cut from the 4.2 sensor, so whatever is inside the connector I do not have. Am I screwed?

[AldoQ]

In my case the 6 pin connector is already cut from the 4.2 sensor, so whatever is inside the connector I do not have. Am I screwed



the connector have a cal resistor,so if you dont have the connector, you need a controller with free air calibration
personally i have a JAW and SLC free form Alan both in working conditions
regards

[kb1gtt]

RCal is of medium importance. It can indicate if you have an LSU 4.2 vs 4.9 and its technically factory trimmed as part of a calibration procedure. As an alternative to using the factory trimmed Rcal component, you can calibrate to free air and use that as your baseline instead. I believe that's what's done by the 14point7 device, while other devices that use the CJ125 will rely on the factory trimmed resistor. So the semi long answer to you question about if you are screwed, is that it depends on the upstream circuit. Assuming you have a free air calibrated setup, you probably want to replace the resistor with something similar to the below, then calibrate with the free air procedure for your driver device.

russian's LSU 4.2 measured 120 ohms
my LSU 4.9 measured 102 ohms.

[AndreyB]

Looks like this one is no longer available, I will inquire if a replacement product is planned.

[Suprazz]

There is a Spartan 2 OEM controller from 14point7 that is cheaper that SLC OEM and work well with LSU 4.9 bosch sensors. I'm using that in the MS3pro PNP ecu I developped. You should consider it. I have the documentation if you need it. The only problem with the 14point7 products is the disponibility (it happen often that products are out of stock with long delays) and the slow answers and slow shipping. I ordered a quite big order from then 1 month ago and the guy too like 3 week to ship my stock because he forgot even after 2 reminder emails... And this is frequent...

So I'll continue to use the 14point7 products until I find something better but right now, I always order many units at the same time to always have in stock and products always work well!

[AndreyB]

http://www.14point7.com/products/spartan-2-oem shows the same picture and same price as http://www.14point7.com/products/slc-oem

I've experienced the same exact shipping slowness while getting my slc-oem

[kb1gtt]

I've had the same issue. I recently lost my OEM version, and had to order another. I decided to try the http://www.wide-band.com/product-p/apsx_d1diy.htm so far so good. They had good enough shipping, good support replies, low cost. I hope to have it in the truck soon, so we'll see if it seems to be accurate or not. I suspect it's going to be accurate enough for my needs. After all O2's aren't for tuning any how, they should be for figuring out when you have wondered away from where you should be.

[Suprazz]

Here is a picture of the Spartan 2 OEM but you're right the price is the same, my mistake.

I have in stock if anyone want to try and want fast shipping!

And about the APSX D1, I also heard bad feedback about accuracy

[kb1gtt]

Do you have a forum post, or youtube video or similar that shows the accuracy claims? From a technology stand point I don't see any significant differences from this controller to pretty much any other controller. I'd like to verify the accuracy claims, such that I can work from data points instead of the rumor mill. I know most O2's are in-accurate for a variety of reasons. Most common reason is the location in the exhaust pipe.

If your going to compare accuracy via this document http://www.diyautotune.com/downloads/Wideband%20Shootout.pdf keep in mind that Bosh assumes that you will not have leaded fuel. The thin coating of lead on the sensor is likely adding some oddities to the overall results. As well they forget to mention if they did things like rotated the sensors in the bungs, effectively doing the test at least 8 times, to ensure the accuracy issue wasn't caused by the placement in the pipe. As well they don't mention if they rotated the sensors relative to the controllers, ensuring that the results weren't caused by MFG tolerances of the sensors themselves. Also they don't tell you if they connected via analog, or digital means. You can get large errors from how you connect them physically, especially the analog connections can have skewing. They note they used an LSU4, but don't note if it was a 4.2, or 4.9. Also O2 sensors aren't for short term adjustments, they are for long term variations. I wonder what was the accuracy at 200mS, from what I've seen most would be much more accurate and the differences would be far less. I see the results from that test as highly questionable, as they didn't publish many of the details of what they tested or how they tested it. As well the 100mS criteria indicates they were likely pushing the innovative controller.

I understand the Innovative unit, which claimed the best accuracy in a 100mS time frame, uses a pulsed kind of sampling approach, which effectively dithers the reading removing some hysteresis during the sampling cycle. I understand this gets a faster response time, but likely causes longer term issues to the sensor resulting in longer term skewing of the sensors readings. Your normal 50kmi that you get from an O2 sensor is likely significantly shortened by this pulsed approach.

If I'm concerned with accuracy, I would only use OEM BOSCH chip(s) like the CJ125, as they have a multi trillion dollar industry who would sew them senseless if they got the readings wrong. All these other after market people just need to put up enough of a story to make a sale. I don't trust any of their accuracy's claims. I look for what the accuracy's could be, based on technology in chips like the CJ125. If the pulsed kind of sampling approach was truly better, we'd see that in OEM equipment. So I base my assumptions of better accuracy on the CJ125 general topology. Both the APSX D1 and SLC-OEM have pretty much the same physical technology. So if there are accuracy issues, it's a software issue not a hardware issue. I have no data showing that one software is better than another software. So I currently make my purchase decision based on a price to support ratio. I got poor support from 14point7, so I tried something else and found a better price to support ratio.

[NBytevenom]

Neat idea if we want to be able to control a WB on-board. Cost effective as well for LeMons teams.

https://www.14point7.com/products/spartan-2-oem

[kb1gtt]

I believe the CJ125 is a much more cost effect option, as well it is an automotive qualified component. You can get the CJ125 for about $2.60 usd on aliexpress. The total cost for this board is about $5-ish.

https://rusefi.com/forum/viewtopic.php?f=4&t=1052