I've still been avoiding arduino in favor of building microcontroller circuits from scratch (concentrating on PIC12F series chips). A recent idea involving Bluetooth and MIDI had me considering development on Arduino with appropriate shields.

My question is how to go from development into production as I'm not sure jamming an entire Arduino and two shields into a production piece is appropriate. Or is that done?

It's done, but more for low-volume and/or hobbyist level stuff.
Arduino is just a handy interface for the MCP microcontroller & a simple IDE/Programming environment.
If you already have 'production' level experience with PIC, I wouldn't switch.
A shield can be cost effective for single digits to low-10s of units. It's also much cheaper on the startup costs. Once you get into ordering 100s of completed units, the extra parts drive the cost up w/o providing usefulness & would eat into your return. Headers are expensive if you're not using all the pins.....

Agreed. It’s fine for small runs. Past that, it’s custom PCB time, or at least a custom PCB with some pin headers so you can solder on an Arduino mini board. Now, unless things have changed, I thought Arduino was using Atmel’s ATMega series of micros, which you could absolutely use in a custom board. Might need to switch to the ATmel dev tools, but they have a reasonable SDK. I don’t really do embedded programming, but I was able to figure it out for a project at work.

For the next step up, there are a variety of domestic vendors that specialize in small runs of custom PCBs. Some can even do the board design, but that part isn’t cheap. Here is the one we used on our project: https://www.rbbsystems.com/ if you have board design files with all the parts and such, they can get you a solid quote. If you need design work, it’s a bit less firm!

- Bret

Thanks for the tips. Now I've got to figure how to add MIDI and Bluetooth to my current circuit.

I'm already working with Microchip PICs and they have the RN4871 which I imagine I can use with the same IDE. I'm going to look into it.

I just want to send switch presses wirelessly. Is Bluetooth overkill? 10 switches. Nothing complicated. The receiver, however, is going to send MIDI program change info.

Take a look at sparkfun or adafruit. They tend to have little single-function boards you can easily hack into a project. I took a quick look at sparkfun, and they had simple RF transmitters and receivers that might work for what you are doing. They also have Bluetooth and I think some variant of zigbee modules as well. Most of them you just hook up to with a serial connection from your micro. Bluetooth may or may not be overkill, depending on how you want your project to work, but there is a little more to it than a simple RF Fire-and-forget transmitter.

There is probably a MIDI shield or board as well, but I don’t know as much about that. I’m sure someone makes something that would work at least for prototyping.

- Bret