As many people here probably know, a development board like the XIAO is typically used for prototyping, Once a product’s prototype is developed and all the bugs worked out, then the mass produced version is designed. As far as the electronics go, this would entail scrapping a development board and designing your customized PCB around an MCU (still can use an ESP32 module such as the WROOM) and add only the components you need (e.g., charging module, voltage regulator, etc.) Development boards themselves aren’t used in commercial products because they are more expensive than designing a PCB “a la carte” using only the components you really need. This can also save space.
Now I’ve been working with the XIAO ESP32C6 and I have to say, it is small enough for my purposes. The Seeed price is $5 for large quantities. In contrast, the cost for an ESP32 WROOM module is about $2.50, but then add in a lithium battery charging module, USB-C connector, voltage regulator, etc., plus assembly, shipping and sourcing all these parts, and you’re probably looking at around $4+.each.
So here’s my question. I have big dreams and hope to have my product mass produced one day. Has anyone ever heard of the XIAO being used in a mass produced commercial product? It seems only slightly more expensive to use the XIAO over the traditional method of customizing the PCB yourself, and the XIAO already is a proven product which includes all the certifications, etc. So I am seriously considering the possibility of working the XIAO into my final design, and I am assuming that Seeed can deliver large quantities of them if needed.
SO I was faced with a similar issue,
My patented Device uses an Nrf52840 in it’s design.
I chose the Hybrid approach, I made a PCB and Used a Xiao instead of reinventing the Wheel when the work was already done. With the proper planning and scheduling Seeed Studio can supply what you need. It is up to however to Plan properly, the old adage " Fail to Plan , Then… PLAN to FAIL!" Applies
In your situation the Cheapness of the chips already , then in Quantity it’s a NO brainer. IMO. Check out the first revision of the PCB, I’m at REV 6, now and the polish is ON!
Man it is Sweet, This stuff goes together better than Peanut Butter and Jelly or Cake & Ice-Cream !
HTH
GL PJ
Battery Power went from 1 day to 27 days for example… The Certifications Seeed has for FCC part 15 Class B devices was a feather in the Cap. BTW! By making No changes to the Radio or RF section the Certs apply.
Hey buddy, thanks for the reply. I looked at your PCB link and very impressive, but ultimately, what does your device do?
I was originally concerned about being able to utilize the XIAO in a mass produced PCB because I couldn’t figure out a way to connect the BAT pads using conventional PCB fabrication options, but I found a great voltage regulator (MCP-1700) which works perfectly on the 3V3 pin. The built-in charger only runs at 100ma (to my understanding) so I am using an external battery charging module anyway (my battery is very large). I’d love to share my project with everyone, but I am still filing patents and stuff so it is still :X for now.
But back to my original question, I’d love to know of/see other commercial projects that use the XIAO. And also if there are any logistical issues I am overlooking. The XIAO could be a paradigm changer considering its cheap price!
Glad to help… So my device is a BLE based security device for Motion Picture Lenses and Camera Bodies. Took me 3 years to get the Patent. (those are very early PCB’s all MSMD now.)
So the Pads on the Xiao do not present any problem for the right tech. READ the posts about it there are a few. I will be posting shortly a new thing and a New New thing for it. The Seeed engineers used the method to solder this test unit so you see more about that. There is plenty of methods for the battery charging and some have even modified the Xiao which you could probably get seeed to sub in your part on a custom build. Check out there services.
HTH
GL PJ
here is a NON spoiler alert pic of said Soldering tech…on a soon to be commercial product everyone is gonna want one…for sure.
Great tech about the lenses and cameras. I’m assuming if someone tries to walk off with a camera, your device detects the signal (or lack thereof) and triggers an alarm, or something like that I guess. It’s amazing what someone can make these days with a 3-D printer and some electronics.
I also didn’t know that Seeed could make a custom XIAO build, it’s still too early but I wonder if they could make the battery charger up to 1A, that’s what I need! I also saw the posts on connecting the BAT pads, but I’m still scratching my head, not really sure I get it or even have the tools for that. I’m waiting now for another custom PCB with a new approach for soldering the BAT+, and if that doesn’t work I will just utilize the 3V3 pin with an LDO! SEEED, PLEASE in your next XIAO version replace one of the pins with a BAT+ pin.
I hope you are making $$$$$ on your camera device! I know that completing an invention design is only half the battle, the marketing and sales is even harder!
i believe the oval shape of the thru hole allows the solder and flux and iron to penetrate… basicly you are soldering a thru hole connection… the small round via will not wick the solder as good… also i assume you can use surface mount technology
I thought for sure (based on your suggestion a while back) that simply creating a plated through hole for the BAT+ and flowing solder throughout would make a good connection. It seems simple, right? But it didn’t work! The connection was not stable. I’m guessing the solder connection to the BAT+ pad was weak, although I tried it a number of times. I’m trying something new now and if it works, i will post about it. I’m not up on surface mount technology and I just don’t have the tools for that.
got ya… yes i have not actually done it myself but PJ did… is the thru hole you are using plated?, a via? Top plane to bottom plane?
maybe it has something to do with the spacing between the XIAO and the board. Did you solder the other pins before or after?
did you place flux on the top of the sandwitch? I am assuming the solder was connecting firmly to the XIAO but was not making good contact to the board? you are going to need enough copper on the board to mate… maybe PJ can give more info
Thanks for letting us know its not working… so we can know and do better!
Here is a picture of the footprint I made for Fusion 360 (since unfortunately there was no support from Seeed on getting the footprint). But the footprint I made SHOULD work just fine, right? I am using the GND pin so I only need the BAT+ pad soldered. I squirted in flux and then soldered the pad to the plated through hole. But… no dice! the connection didn’t work at all in one PCB and the second PCB I had printed worked spottily.
You might be right, the spacing between the XIAO and the board might be too much. I soldered the pins first and then the pad second. Maybe I should have done it the other way around.
Interesting thanks for the picture… i think you should use the battery ground as well… i am not sure leaving it off will allow for good charging… maybe pre-tin the top or the XIAO before sandwitching maybe do corner pins first to hold in place… as i am sure you know… if the copper is to the proper temperture the solder will flow … especially with the aid of flux so flux it… make sure you have an iron tip that can really get the heat into the oval place the iron tip thru the hole to heat the xiao pad and thru hole at the same time then apply solder and it should flow to the joint… Just my opinion
So Yes, It’s like someone always watching your gear…Motion, Drop, Moisture, Temp. Lock/Unlock BLE , Android & IOS app. to operate.
LOL, yep I started with cardboard rings and magnets , My first 3D printer was a Bday Gift.
I printed the rings from PLA and Later the whole thing in Carbon Fiber, So Strong I can Stand on one (165LBS) on a good day
Now PCB , Patent and lots of interest… Two Trade Shows NAB and FISH ON!!!
A lot of Hard work, Focus and some vision for the future. Oh’ and a few buck doesn’t hurt Patent attorneys are expensive, Well the good ones anyway!
Meanwhile, Tell me the solder bridge in the picture is intensional and also tell me your using a weller 200amp soldering Iron because , Brother that soldering looks Terrible
So the foot print looks spot on , so there’s That
The ovals are too small, double check those spaces too. looks wide of the mark.
The plated holes don’t look good either, who made that PCB?
Your Center pads look very good , Tight! You sure the mounting ears tabs, for the USB-C port are NOT keeping it from sitting perfectly flat and you must be using pins. Ditch that and use the Surface mount Less holes too in PCB it super easy to work with, even if you only have a soldering iron. GET solder PASTE too.with the rolled solder as well.
otherwise increase the size of the "plating " in the hole 1mil to 3 or 4 mm. I wouldn’t waste your time though. do the SMD
what also you do need the BAT(-) minus as GND look at the pics I posted on the PCB you can see and they are FATTER traces too! USE decoupling caps also and a larger one next to the Xiao’s 3v3 and GND pins.
Thanks for the feedback! The solder bridge was not intentional, but that was not causing the issues. I finally received my latest PCB version in the mail. I get them from a company called Sunstone Circuits. They aren’t the cheapest, but I am in the U.S. and I’m not comfortable sending my propriety stuff out to PCBWAY in China, even though they are dirt cheap. You don’t think the PCB is good quality?
So I put this one together today and it actually works! I put Kapton tape over the BAT- to protect this from accidental solder flow from the BAT+. I know some XIAO purists here won’t like not using the BAT-, but it is connected to the GND pin. I am not using the built in charger anyway because 100ma is too small for my battery. So I fluxed a wire (without insulation), soldered it to the BAT+ pad on the XIAO, then passed the wire through through the now GIANT BAT+ PTH and inserted the XIAO into the PCB, then solder the other end of the wire to the plating in the PTH. This works with no issues! If anyone wants the Fusion 360 component, I’ll try to figure out how to post it on Github.
You suggest doing SMD, i don’t know much about that, don’t you need a reflow oven for that or something? And yes, my soldering is terrible , no offense taken!
Good luck with your product, sounds great and I hope you make lots of $$$. It’s hard bringing new products to market. And I know all about patent attorneys being expensive, I actually am one!
Counselor If it works then that is Awesome… You will get there. Keep reading and watching and by all means post ANY questions you have, Lots of smart folks here willing to help…
GL PJ
seems like the Licensing guys are even more…
My pops was a DA and Brother an Orthopedic Surgeon Pro’s cost Dough!
however to Plan properly, the old adage " Fail to Plan , Then… PLAN to FAIL!" 
Applies 
PJ 
The Seeed engineers used the method to solder this test unit so you see more about that. There is plenty of methods for the battery charging and some have even modified the Xiao which you could probably get seeed to sub in your part on a custom build. Check out there services.
everyone is gonna want one…for sure. 
, Tight! You sure the mounting ears tabs, for the USB-C port are NOT keeping it from sitting perfectly flat and you must be using pins. Ditch that and use the Surface mount Less holes too in PCB it super easy to work with, even if you only have a soldering iron. GET solder PASTE too.with the rolled solder as well.
You will get there. Keep reading and watching and by all means post ANY questions you have, Lots of smart folks here willing to help… 