Hacking the Electric Imp (Cortex-M3 Wifi in SD Card)

The Electric Imp has recently been announced At the bottom of the announcement: Electric Imp will retail for 25 USD and manufacturers should be able to buy the card in bulk for as low as 1 USD/pc. Developer preview Imps and the developer kits will be available in June or July 2012.

I'm much more interested in the hardware than their Squirrel VM programming system so I'm curious on how the software is implemented for this device. They are using a STM32 Cortex-M3. That line offers up to 1MB flash and 96KB RAM. Any guesses on which Broadcom chip they are using?

Are there any free OSes that can run in that amount of memory and support wifi? Or cheap pay ones?

How does wifi support work in a small environment? I'm used to working with soft-MAC chips on Linux and the Linux wifi code is several hundred KB in size. Do systems like this use hard-MAC chips?

Laptops use Wifi boards worth around $10 in 10K in my est from a few yrs ago. Volume useage drives the cost down. $1 is someone's pipe dream for phisshing mfg who need 1m+ units.

SunnySkyguy said:

Laptops use Wifi boards worth around $10 in 10K in my est from a few yrs ago. Volume useage drives the cost down. $1 is someone's pipe dream for phisshing mfg who need 1m+ units.

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Electronic Imp wants you to sign up for a subscription plan to access your Imps from their server. The $1 number is likely subsidized from these fees.

The cost of wifi chips has greatly declined in the last few years. Imp's BOM cost is probably in the $3.00 range at high volume. It should be possible to wholesale the Imp for $5-6 and make money without needing a subscription subsidy. For example, you can buy retail USB Wifi sticks for under $3.00 in China.

I'm not sure on the $25 price for the developer version (which doesn't need a subscription). I just purchased a couple couple of **broken link removed** from Electron Hobbies in Australia along with the **broken link removed**.

Programming is interesting with the Squirrel VM programming system. From a WiFi perspective, it's just adding the relevant TCP/IP function in the planner, telling it what the address is and having your code 'block' output value's or receive values which and then you connect the two in the planner. So it's really all looked after for you.

Re "Are there any free OSes that can run in that amount of memory and support wifi? Or cheap pay ones?" - I haven't seen anything and I'm not sure without going and pulling the thing appart physically if you would be able to load something. You have some GPIO pins, but all the programming is done via WiFi.

smitthhyy said:

I'm not sure on the $25 price for the developer version (which doesn't need a subscription). I just purchased a couple couple of **broken link removed** from Electron Hobbies in Australia along with the **broken link removed**.

Programming is interesting with the Squirrel VM programming system. From a WiFi perspective, it's just adding the relevant TCP/IP function in the planner, telling it what the address is and having your code 'block' output value's or receive values which and then you connect the two in the planner. So it's really all looked after for you.

Re "Are there any free OSes that can run in that amount of memory and support wifi? Or cheap pay ones?" - I haven't seen anything and I'm not sure without going and pulling the thing appart physically if you would be able to load something. You have some GPIO pins, but all the programming is done via WiFi.

Click to expand...

They have not turned on subscriptions for developers. But they have stated numerous times that they want to charge a subscription fee.

It is a Broadcom SOC in the package. It is running a Broadcom supplied RTOS with wifi support. Of course Broadcom wouldn't let you use this code unless you sign up for a million chips.