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Would everyone want FCC certification for the WIXEL?

Note to moderator: Please pin this post if possible. Some time ago, while corresponding with a pololu rep, they suggested I post this topic to see how many were interested.


Please answer this post with a short reply indicating whether you think Pololu should seek FCC approval for the WIXEL, and whether you would support and encourage them to do so. Pololo reps have told me they are considering such certification, but it is a very low priority. Further, they suggested I post this on the forum to see how much interest there is. So Pololu wants to hear from us .

Let’s limit any contrary discussions here unless they are from Pololu reps, and let this be more a survey then anything else. Having had significant conversations with both Pololu representatives and TI engineers about this, the limitations that would come with such certification are well understood, but would be of great value just he same.


As we all know, the wixel is likely to be the most ideally packaged support structure for the powerful TI cc2511f32 chip we will ever see. This feature packed System on Chip offers plenty of code space and resources for developing very powerful and commercially viable applications. Thanks to Pololu, the wixel’s compact size and small components offer a significant head start to product development. Having developed what I believe is a very marketable product myself based on the wixel, I know this to be true. The only issue is the FCC certification. And while other pre-certified RF modules are available from other suppliers, few offer the versatility and feature set of the wixel.

The challenges, and proposed solutions…

1. The wixel documentation states that it is based on a certified TI reference design, and therefore should pass muster with the FCC. Unfortunately according to a TI rep I consulted with, the TI reference design is slightly different. Apparently some components, such as the impedance matching balun are different in the wixel as compared to TI’s design. In addition, the TI reference design in question did not even get its final certification from the FCC until November 2013, after the wixel documentation was published. However, due to the somewhat loose regulations regarding the portion of the 2.4Ghz band in use by the wixel, coupled with the low RF power involved, there is little reason to think any wixel based design would not pass. The problem is, without a reference design to leverage, the testing and application costs associated with certification is a major discouragement to any developer hopeful of marketing a product prototype.

2. It would be somewhat foolish for a Pololu customer to get the wixel certified on their own, with their own application, even if costs were not a concern. Pololu could make a change or improvement to the basic board (for example, there has been some talk about extending the wixel range) at any time. Any such change would then invalidate any independently acquired certification once stock of the old version was gone. This is another reason why it is best for any certification efforts to be spearheaded by Pololu.

3. It has been argued that according to FCC rules, such certification would have limited value, because any code added or changed would invalidate the certification. After having some informal discussions with both TI engineers and some legal advisers, I do not believe this is strictly the case. First of all, the FCC is not out to drop the hammer on everyone trying to turn out a product economically. They are there to ensure harmonious interoperability between the tens of millions of devices available commercially, have always done a good job at this, and are constantly tweaking their rules to help small developers. These rule changes evolve slowly, as they should. But all my research indicates that if Pololu developed a somewhat comprehensive application that fully utilized the radio (such as its bi-directional wireless serial port emulation), and had their module certified with this application active, we as independent developers could then leverage both the hardware module design and our own applications. Granted, it is technically true that our own applications would mean re-certification is necessary, but there are some ways to mitigate this. You could, for example, start with Pololu’s pre-certified code and state that you simply added a data layer to the existing application interface (API) provided by Pololu. This is very similar to using another company’s RF module and incorporating it into your design. Technically, in both cases, it should still be re-certified. But the cost difference would be a solid 1/10 reduction. And in truth, many start-up companies don’t bother re-certifying initially when they are able to start with something that has already passed the process.

Even if it is of limited value for pololu to seek such certification, it would still allow developers to leverage their certification to reduce their own costs. Besides opening the door to much more wixel based product development, doing so should result in enough revenue from increased wixel sales to more than pay for their investment. Lets all let them know we’d appreciate their efforts in this area.

Sorry Wixel is obsolete. Move on. Xbee series 1. FCC out of the box. $19.

I would like to see Pololu get FCC certification. Perhaps that would spur Pololu to increase the Wixel’s range.

The XBees are not some newer thing; they were out before the Wixel was released, and the Wixel was never intended to compete with XBees. Rather, the Wixel is meant for those who want a user-programmable module with integrated USB and wireless. They can plug into a breadboard for general microcontroller projects, and we have seen people using the Wixels without using the wireless capabilities. For those who want to do larger-scale, commercial wireless products, the XBee seems like a good option, but the Wixel can also be used as a prototyping development tool for those who might want to integrate the CC2511 directly into their final products.

- Ben

Yes. I believe this would be a good thing.

I think it would be a good idea to get the FCC cert. I am currently developing a product based on wixel to wixel communications and would very much like to claim FCC cert. when it goes to market.

While it has been a long time since I started this topic, I wish to continue to encourage Pololu to seek some level of certification, and I’d like to comment about the range. As near as I can measure PCB traces, the folded “F” antenna configuration on the Wixel seems to be 1/4 wavelength. As I too have product plans that involve wixel, I have done some experimentation adding a similar folded PCB trace totaling 1/2 wavelength, cutting the existing trace on a wixel, and there connecting my substitute with a very short length of wire. This wixel was used only in the transmit side of my test, and I honestly didn’t expect it to work at all due to the complexities of impedance matching. but I was pleasantly surprised to find my previous range of about 30 feet had now increased to a full 50. I’m sure i just got lucky here, but the point is that it is quite possible the wixel range could be improved some by antenna tweaking, if some REAL RF engineers made the mods. So if Pololu does consider going for certification, they may as well see about optimizing the range first, because it now seems definitely possible.