Using a PIC microcontroller for my project

Hi,

I'm an electrical engineer but rather new to actual microcontroller-based design and programming with 'practical' purposes. I'm considering whether to use a PIC controller for a personal project but due to my lack of experience I have a few questions, which I´m sure will sound trivial/stupid to the more experienced user.

First of all, I inted to use the controller for a simple device that would have to send data to a PC on a extremely reduced bitrate (we're speaking of a few bytes every once in a while). The device would obtain said data from a set of analog sensors and then send it to the PC after limited processing. It's presumable that there could be a number of such devices in the same room sending data to the same PC. In the first stage of development something like USB would do for the connection between the device and the PC, but for the final product I would expect to use some sort of wireless technology. My idea is to sell the product, but only in a very reduced amount (initially, definitely not more than 40-50).

In terms of electronics, apart from the controller itself I would only need the sensors and a few analog multiplexers to connect the sensors to the controller's analog pins, and then whatever I need for the communication with the PC.

Here my questions:

- Let's suppose I have developed and tested the device on a Microchip development board. What's exactly the next step? Would I have to design a PCB board from scratch and then send my project to a manufacturer or are there some sort of 'templates' that I could use, given that basically all I need is just the controller/communication devices and a few multiplexers (they would be connected to the sensors, but those would not be on the PCB board). Except for the multipleyes, I bet something like this has been needed thousands of times.

I have no previous experience designing PCB boards. Given the very reduced number of boards I would need, wouldn't it be extremely expensive to manufacture the boards? Is manually assembling the board / connecting the components together a possibility at all? I wouldn't mind doing that if it could be easily accomplished. What would be the best option?

- Regarding the wireless communication, what would you suggest? I have seen cheap bluetooth modules (like this one, with an USB interface: **broken link removed** - sorry german) or things like the (I believe) better known BTM-222 (**broken link removed** ). Would it be easy to connect such a device to a PIC microcontroller? Are there libraries or any kind of support? I'm a bit put off by the fact that the microchip wireless development board is very expensive and that there's little or no information on bluetooth that I have seen. I guess it won't be as easy as pluging one of the devices I linked above and start transferring data to the PC - although the latter includes SPP, which could be enough from what I have read in other posts?

- What PIC would you suggest to use? Given that my processing power / communication bandwith requirements are very reduced I had thought of the 8-bits PIC18 series with USB support. Does that seem like a good choice, especially considering the bluetooth / wireless thing?

Thanks a lot in advance and I apologize for my ignorance and the rather silly questions!

You might consider looking at the Arduino as an entry platform for your microcontroller work. It's a bit more plug-and-play than the PICs. Additionally, you can buy/build "shields" which connect to a pin header on the main Arduino board to give you expanded capabilities (I/O modules, ethernet module, etc).

As for cheap boards, check out ExpressPCB for fabricating some cheap, simple boards. The downside is that you have to use their proprietary CAD software, but their prices are pretty cheap for what you get (all on FR4). You can also use any-board and wire up your circuits like in college.
http://www.circuitboards1.com/wp-content/uploads/2011/07/Prototype-Board.jpg

If you really want to go DIY, google copper etching PCBs. There are some videos on YouTube to give you a feel for the process too... I think someone partnered w/ DigiKey to make some of them, IIRC.
http://akashi.sites.uol.com.br/Arduino/Images/DSCN0847.jpg
You can buy the chemicals and do you own ink-based mask, then etch off the copper @ home. Be careful, the chemicals are corrosive, so wear proper protection (safety glasses/face shield, chemical-resistant gloves, etc).

You can also go the PIC route, but I think you'll get off the ground faster with the Arduino. If you want to dig into the nitty-gritty details more, then go with the PICs. I had used the 16-series PICs in college, and messed around a little but with the 18's. They are all quite robust, but configuring the registers is often the biggest challenge.... you spend a lot of time reading the PIC spec sheet/manual to find the one bit you forgot to set.

the wireless solution is always about distance, if the distance is short, **broken link removed** could be an option, but maybe you can go the **broken link removed** way, there are more**broken link removed** or UART communication and send them via RF without further programation....