Wifi DipCortex

[Carl-SolderSplash]

WIFI is something I've wanted to do for a long time, but there are a lot of technical and regulatory challenges around it. If your 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 an low power embedded project where your not running an OS it gets a lot harder. So the only real option is to use a WIFI module, 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. Making getting the product in to the market a lot cheaper. The goal was to squeeze this module, the TI CC3000MOD, on to a board the same size as the DipCortex which is/was a massive challenge.


(Incomplete 3D model of the Wifi-DipCortex)

But we have done it! The PCB outline has been extended slightly past the standard DipCortex footprint, this enables us to get the components all on the top side, which reduces cost. 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 has saved some 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 optimal PCB layout and the 50ohm microstrip leading to the antenna, which we have followed closely

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. Our final checks this week have shown the recommended antennas are hard to come by. So we are now tweaking the antenna footprint for a part that is much more readily available, whilst maintaining the maximum gain so we can still use TI's module certification for FCC, IC and ETSI. Once that is done we ship it off for PCB manufacture and wait a month for the boards to come back.

TI's module control software is open source and the first goal is to port that to the LPC1347.

In summary we have a tiny, low power device with lots of IO and peripherals ready to power your next internet connected project. I can't wait to get my hands on the PCBs!

[Dave]

This looks very interesting Carl. I'll have to have a couple of those.

Trying to think of some nice home automation projetcs for these.

[Carl-SolderSplash]

Boards should be with us at the end of the week! Not sure on a release date as yet.

Progress this week,
I wired up a standard DipCortex to a CC3000 evaluation module and logic analyzer and started to port the TI CC3000 driver code to the LPC1347. TI Driver code compiles fine so they have put some thought into cross platform/compilers. However there are a lot of blocking functions that have the chance to never return if something goes wrong at some point I will need to look at where I could add timeouts to recover.

The first task was writing an SPI driver that the TI driver can use to control the wifi module, TI have a guide on their wiki telling you which functions were needed etc, I found it easier to download the MSP example code and convert that for the LPC. With that done and the module able to be initialised, I added USB code to give me CDC com port for control and debugging.

I was able to connect to encrypted access points and ping the module, success! But once I had added a simple UDP transmit over the network I ended up getting stuck In the TI driver layer, hung in a while loop waiting for the module to respond.

Querying the firmware revision of the module I found it was quite out of date. TI provide code to patch it with an MSP or TI device which I have now ported. After triple checking it, so that I dont brick the module, I hit the button, success. The module now reports to be the latest issue and the UDP transmit now works!

Next tasks are

• Implement the SplashBase protocol
• Add non volatile settings
• Implement proper delay timing
• lots of tidying

[Carl-SolderSplash]

Boards came in this morning, we re-flowed four of them this afternoon and have them working! Connecting to WiFi and communicating to the SplashBase Locate & Control PC Application.

Success!

[Dave]

Very nice Carl.

Any idea on price yet?

You can put me down for a couple of these.

[Carl-SolderSplash]

Hard to say at the moment on price and availability,

Next week we are taking it to an IoT (Internet of things) show in Cambridge, we want to see what people make of it there, following that we have a few distributors that are interested in demos.

Our aim is to gauge response, if positive look to invest and build a big batch for distribution. Rather than the organic approach we have tried on our own so far.

As soon as I have some to sell Dave, i'll be sending you a discount coupon first

[Dave]

Thanks Carl

[zycar]

Hi Carl .. it looks like you are the company,who finally figure out the MCU connect directly to "regular" WiFI.
There are a lot projects outside, but all of them uses proprietary RF communication ... this is what I'm looking on the internet.

I hope the price will not be high (you know students ), and you are shipping the products also to the Czech Republic ...
Will do observe your product list for WiFi DipCortex success.

What do you think about birding the TI CC3000MOD with ATMega (i.e. 1284p) ?

[Carl-SolderSplash]

Hi Zycar,

Thanks for posting,

No plans to support Atmel devices I'm afraid, they are very popular in the maker market but we want to concentrate on more capable ARM based boards.

We have some exciting news in the next few weeks about our dip cortex range that will make it more accessible to people learning to code