Design Goals

Create a simple adapter to plug in the WiFly module, sacrificing the minimum number of usable circuits on the SmartBoard Baseboard. The WiFly can then be used as another communication channel for the SmartBoard.

Initial Concept

From the initial concept, I connected the WiFly as you see here. This was enough to prove the concept and develop a more "conventional" schematic.

Schematic

As you see this is mostly just providing an electrical interface.

Smart WiFly v1.0 Schematic

PCB Design

The PCB is providing a stable mechanical as well as the electrical interface.

Smart WiFly v1.0 PCB

With the pin spacing of the SmartBoard WiFly, you can also use this module with a proto-board, but note that this will plug in on the outer row of sockets on the proto-board.

Order this PCB

BatchPCB is gone, and I haven't posted this elsewhere. Contact me to see if I have spares or am preparing an order.

BOM

And lastly, for a BOM, I had everything I needed laying around, so I didn’t create a BOM. I encourage you to double-check my notes here so you don’t get something you can’t use.

Build this device

As simple as this is, you may want to skip this set of instructions, but at least scan them for details not to overlook.

	SmartBoard baseboard just visible on the left, Smart WiFly in the middle, WiFly above that, and the mbed at the bottom.
	Note how the mbed nestles between the leads of the Smart WiFly bridge board. When they are lined up together, the pair install easily into the baseboard.
	Installed onto SmartBoard
	Powered and Connected!

Handy Tools:

• Fine tip soldering iron
• Small diameter solder
• A steady hand
• A good magnifier (an inexpensive eye loupe works well)
• A small bench vise to hold the PCB

Recommended Construction Sequence:

1. The surface mount caps. I chose large footprint parts that are easier to hand solder. I recommend you place a little solder on the PCB pad, then remove most of it, then while holding the cap in place just touch each end to reheat the solder. Once it is attached, you can apply just a bit more solder as needed.
2. Double-check that the caps are aligned on their pads.
3. Install the socket strips for the WiFly. Just tack the corners, then check the alignment, then finish soldering them down.
4. Install the stand-off connectors on the bottom side, so the top side of the PCB stands up tall (the long leads are sticking down below the board. If you do not seat the connector fully onto the board, it may be easier to perform that extra soldering step on pins 1, 10, and 20. Then repeat on 21, 30, and 40.
   • On the top-side, the stand-off connector pins should be just barely stickup up above the PCB. Make sure they are of uniform height before you start soldering.
   • Solder each of the pins on the top-side.
   • Turn to the bottom side, and carefully heat and solder several, if not all, of the pins.
5. Install the wire screw terminals. Note that there are two rows (one with 7 pins and the other with 4 pins).
   • Unless you have a version that supports wire entry at 45 degrees, it will be difficult to use the inner connector, so you'll see I left it off of the build shown in the photos.
6. Install the reset switch.
7. Install the 3-pin header for the jumper.

Hardware Checkout

1. Inspect the connections, then inspect them again. Look for good soldering quality, and no shorts to adjacent circuits.
2. Checking continuity from pin to pin per the schematic. Check that the signals are not shorted to adjacent pins.
3. Install the SmartBoard WiFly onto a suitable baseboard, but do not install the WiFly module.
4. Power up and probe the WiFly strip socket pin 1 to ensure that it has only 3.3v, as anything higher might destroy the WiFly module.
5. Power down and install the WiFly module.
6. Test with the following program. For this program, you do need to refer to the WiFly User manual.

Software Checkout

#include "mbed.h"

Serial pc(USBTX, USBRX);  // defaults to 9600 baud
Serial wifi(p28,p27);

int main() {
    pc.printf("Test Wifly!\r\n");

    while (1) 
    {
        while(pc.readable())
            wifi.putc(pc.getc());
        while(wifi.readable())
            pc.putc(wifi.getc());
    }
}

At this stage, you can power up, run your favorite communications program on the PC and interact with the WiFly module. Start by typing "$$$" and look for the command prompt from the WiFly module. Long before this step, you should have downloaded the WiFly documentation. There's a lot to read there, but you can find good instructions to help you start up, connect to your [hopefully] secure network, and start experimenting.

What next ?

That's up to you, but you might be interested in the Smart WiFly WebServer.