Hi all,

I've not delved into this part of the forum before, so my apologies if this is in the wrong section!

A little bit of back - story.

I have an idea to measure air pressure, and then to have it sent to a laptop or smart phone, where it is display real time on a graph.

I've looked into ways of sending the data, such as bluetooth, but the problem is that if I wanted to produce and market these, I think I'd have to pay for a licence.

I'm not wanting to make the product on a large scale, no way would I produce 3'000 units!!With the licences costing about $4000, there is no way I could afford to incorporate something like Bluetooth.

I was wondering, if anyone could suggest a means of transferring the data which is free? Or perhaps I have mis-understood the licence fees?

Thankyou for you time,

Sparky

 

What's the target cost & quantity of your device?

 

I was wondering, if anyone could suggest a means of transferring the data which is free? Or perhaps I have mis-understood the licence fees?

I would be interested in knowing where you got this license information for BT from?

You can certainly transmit your data via an of the shelf RF-module to a device to your computer which communicates via RS232 with your computer.

 

The retail price would be about £100, that's including components, casing, PCB, etc.

I hope I could make a profit of about £40-£50 on each one.

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Here's the microchip website, regarding licences:

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2680&dDocName=en551866

 

Well, I can't help with the license fees, it seems that if you want to use their BT stack you'll have to pay for it. What if you use a BT device off the shelf and try to hack it to transfer the data to your computer? Would you still need to pay license fees?

Well, I'd definitely go the RF-module and RS232 or USB way. I even think properly encoded on the transmitter side I would be able to just read the decoded signal on the receiver side if just plugged in into the RS232, at least if I use a low baudrate. Thus I wouldn't need a PIC in the receiver device to handle communication...

 

I found this ebay item: 200393339984. It's a USB to TTL converter. From there I guess it takes a PIC and RF-receiver module... Cost shouldn't be higher than:

USB-TTL converter - $5
small PIC + external components - $3
RF receiver module e.g. MICRF007 + crystal - $6
enclosure - $1
PCB - no idea

$15 + pcb + software development (for the receiver)
Are there fees for using USB drivers commercially as well?