Best posts made by frenchclem

Hello there,
So after some reading, phoning, thinking, again and again about FCC/CE Certification here is the plan.
I'm not going to go for the FCC Certification, as it's way too expensive, but I'll run the test myself for CE compliance.
When FCC needs to be done by US agencies, the CE can be self-certified : you run the tests with the appropriate tools, make sure your design respects the requirements, and if so, keep the results in case anyone asks anything.
Now pretty much everywhere, I read that if your product is CE compliant, then your chance of getting the FCC on the first run is very high. Dropping the cost to a "small" $5k or so
So first, CE self certification, and then if needed/wanted/asked/ ... FCC, IT, ... other certifications. Meaning so US selling first just Europe. Are there many US folks using Mysensors ?

To run the test, I'm working with my University which has all the tools, and knowledge to assist me. Could be an interesting project to run with some student ... will see !

So regarding the design, zero risk must be taken regarding the RF part :

• the filtering components will be replaced by a Balun Filter from JOHANSON (http://www.johansontechnology.com/datasheets/baluns/Johanson nRF24L01_nRF24L01+_App_Note.pdf)
• I'll add a shielding on top of the RF part. Still looking for the right standard, low cost, easy mounting shield

I share a great guide from TI about antenna design : http://www.ti.com/lit/an/swra161b/swra161b.pdf
Now I want to try the Inverted F antenna presented in my early post, a Di pole antenna (no more Balun Filter), and Chip antenna and compare them the standard Meandered Inverted-F Antenna (MIFA) we all have on our NRF board !

Dear MySensors Community,
I'm thinking on lunching a project aiming to making a cheap, compact, and less soldering solution for the Mysensors enthusiastic people. As Mysensors project is aiming at less programming
So the base line is : a $7 all in one Mysensors+NRF24L01
I know the Sensbender board is here, but you must solder a NRF module on top of it, and it's not so cheap.

In more details here is what I have in mind : (nothing new really)

• ATMEGA328P
• NRF24L01+ with PCB Antenna OR Chip Antenna
• ISP programmer Breakout
• Temperature sensor (maybe humidity)
• break out of main GPIO
• power side : Battery supply on 3.3V direct, or 5V external with 3.3 regulator
• SMC component not smaller that 0604
• option on PCB : space for micro usb connector, and SMA connector

I have already quoted a BOM, I'm waiting for PCB and PCB assembly quote from 2 manufacturer. I'm quite confident that this is feasible for 200 or more boards.

the main challenge here, from my point of view is wireless connectivity with chip or PCB Antenna. The rest is open source and all over the web.

Let me know your point of view.

I'll update the schematic I'm working on soon.

@scalz Yes, I know I'm not inventing anything, everything that I propose already exist
the only, and MAJOR difference is the price : I'm following a design to cost process. What does it means : I take available hardware/schematics : NRF, Arduino (Sensebender, and other good board), ... and I try to redesign and make it as cheap as possible.
The nrf51822 is indeed the killer, BUT it's not working yet with MySensors

And I totally agree with you, if you work in HW and if you are not focused on the future (new chip, new protocols, new project, ...) then your project life expectancy is very little

I obviously won't lunch mass production, so I'm running the process with 400 boards batch. So far, only based on hypothesis, meaning its pure fiction, meaning there is a margin of error in my calculation. The more I will progess, the more the margin of error will be important, and the better I will fine tune the final price.
And I'm pretty sure that if we talk about bigger production batch, then the cost of a simple board could be as low as a couple of $

Look at the low cost airline company, they didn't invent anything, they just optimized everything to drive cost down, and now they are very successful company.
Look at the new Raspberry Zero (produced in EU) : given away for free with a magazine, and then sold for $5 !!
I give out those example to illustrate that innovation is not always the key to success and to illustrate that the cheaper you go, the wider spread it will be ! (no need to add : if the quality is here)

And just to be clear, I'm not doing this to earn money, because low cost, and small batch are usually not big money maker.

Now clearly, if you tell me you will manufacture your Mytinycamel, and sell it under $7-10 fully equipped (board + radio) then I'll reconsider the project. and don't worry, if I didn't want to be challenged on the project I won't be here talking about it !
"Too bad we didn"t met when I started my projects..." => It's maybe not too late !? If we are after the same goal, we can maybe add our skills ...