WiFi is something we have wanted to do for a long time, but there are a lot of technical and regulatory challenges around it. If you’re running an OS on an embedded PC like the Raspberry PI, WiFi is simple, you buy a cheap dongle and the intelligence is in the driver.
For a low power embedded project where you’re not running an OS it gets a lot harder and that means it’s expensive. So the only real option is to use a WiFi module and these are normally expensive.
A few months ago, whilst designing the DipCortex, we identified a module that is low cost and comes with FCC, IC & ETSI certification, saving huge costs assocaited with getting radio equipment through testing. The goal was to squeeze this module, the TI CC3000MOD, on to a board the same size as the DipCortex which was a massive challenge, as the DipCortex is sized to replace a 40pin DIP package.
This week the PCBs arrived, we assembled, re-flowed and powered them up, flashed the Cortex M3 with our code and connected to WiFi, a complete success! The PCB outline had to be extended slightly past the standard DipCortex footprint, to enable us to get all of the components on the top side, reducing assembly costs. We also had to sacrifice the reset button, so boot loading via USB is now done by removing the USB lead and re-connecting it whilst holding the boot button. Switching to a Micro-USB connector gained us some valuable space as well.
We have spent a lot of time routing and re-routing the board to perfect the layout, it is 4 layer like the standard DipCortex with full power and ground planes. The modules datasheet has advice for the ideal PCB layout and the 50 ohm microstrip leading to the antenna which we have followed closely to ensure good wireless performance.
The CC3000MOD is connected to the LPC1347 via SPI, these SPI pins are also routed to the 40pin connection and the pin out is identical to the DipCortex.
This Thursday we shall be showing off our new creation at IoT13 in Cambridge as an exhibitor. This is a massive step for us, the most influential people in the UK in the IoT (Internet of Things) space look to be attending and we can’t wait to show them what we can offer. Following that we intend to gauge interest and approach major distributors to demonstrate the module.
If you are interested in the WiFi DipCortex please do let us know by completing our interest form, only once we know what demand there is can we plan for manufacture.
A new product page will be updated over the next week with the specification and details.