Hi,
I need to communicate 2 devices wirelessly, 1 or 1.5 meters away from each other. I just need to send a command, it means, I send HIGH value to receive HIGH value in the receiver, actually the transmitter side is a button.
The constraint is to use a pre-certified module to avoid a future process certifying it plus the money to get it certified.
Could you suggest the best RF module solution in terms of cost and simplicity?
Thanks in advance
Certified to meet what standard? What future certifying process are you concerned about?
Wireless devices that work at 2.4GHz and at 433MHz are not required to have licences in most countries.
...R
kiniman:
The constraint is to use a pre-certified module to avoid a future process certifying it plus the money to get it certified.
The exact requirements for that will likley depend on what part of the World you are in perhaps ?
Certification in general applies to a finshed product thats put on the market for sale.
So unless the chosen module is say fixed frequency, is not re-programmed in any way and has its own fixed antenna, I suspect you cannot dodge the certification process.
To have the product ready for sale I understand that it needs some certifications, specially for wireless products...I would use it in Europe.
I would use a simple rf 433mhz transmitter and receiver, but I need to avoid the cost of certifications or most of them. So whether I have to use a certified module, what wireless technology/model would you use for this case?
thanks for your replies
kiniman:
To have the product ready for sale I understand that it needs some certifications, specially for wireless products...I would use it in Europe.
If you want to sell a product in the European Union it will almost certainly need a CE mark. How a product qualifies for that is IMHO far beyond the scope of this hobby Forum. You need to get advice from people that you know are competent to give it.
I think most European countries have Government agencies that help new businesses. I suggest that they would be the best place to start looking for advice about product certification.
...R
What I would like to know it is not about certifications, it is what product/technology (wifi,rf,zigbee) module (certified) would you use for a this simple application.
Thanks
That is known as OOK: On - Off Keying. Look for OOK or ASK in the Modulation section of the description
I would also concur that this is not the appropriate place to seek advice for what is a professional product.
If you dont know enough about the topic yourself then you need to employ a professional who can advise and is prepared to accept liability for their advice.
As for which module, then just about any of the proper, packet based FSK modules would do, they can be configured and controlled in a way that should make a product reliable.
I have no idea which modules are 'pre certified' and I dont see what difference that makes either, the end product will be needing to follow the CE Radio Equipment Directive (RED).
And if the devices are only at most 1.5m apart some form of optical\infrared link would eleiminate the need for following the RED in the first place.
Thanks both for the answer. According to what I read in many articles, it seems that there is big difference in terms of cost and time from using a pre-certified module or design your own rf device...
Another business consideration is the device you choose may not be available the next time you need it.
Paul
Modules increase the BOM cost, but they also decrease the NRE cost for initial design as well as redesign when you fail the RFI test. A certified RF module doesn't exclude you from the requirement to certify your product, but it does make it much more likely your product will pass testing on the first try. The question of whether it makes more economical sense to roll your own, or pay a module manufacturer to do that work for you depends on your production volume. If you're going to be making the product in quantities of millions, it's likely going to be worth spending more up front to save money on the BOM. If you're going to be making the product in quantities of hundreds, likely you will come out ahead by using a module. Note that Arduino uses modules in all their RF products and they probably expect to produce these products in quantities of tens of thousands.
kiniman:
What I would like to know it is not about certifications, it is what product/technology (wifi,rf,zigbee) module (certified) would you use for a this simple application.Thanks
Any protocol that has a name WiFi, Bluetooth, Zigbee, USB, ... has an organization that requires you to follow their licensing terms and that includes some form of licensing fees in most cases. The only exception is for pure resale. As soon as it looks different you need to test, certify, list your product and pay.
To give you an idea have a look at the Bluetooth page.
Another option could be infrared. Its simple and easily stoppend by walls (less interference issues).