> I'm a bit surprised this hasn't been done before.
It kind of has been. This is not the first tiny low-power microprocessor out there -- it's just that ARM keeps pushing the envelope. The last "most power-efficient tiny 32-bit cpu" was Cortex-M0, of which this one is an evolutionary improvement.
Most of the embedded industry is still using really simple 8 or 16 bit microcontrollers. The business stragegy of ARM in the space is to push more advanced and complex cpus down to the space and grab marketshare by providing chips that are easier to program. It also helps that the size of the chip itself is a complete non-issue (the article referred to 1mm², while in reality the area for the core itself is actually less than 0.01mm² on a 40G process), and ARM can sell code density because they have more powerful instructions than the typical microcontroller, so while their cpu is bigger, the memory it needs is smaller.
No reason why should not be solar powered. Around here all the parking meters are solar powered, just for cost of installation reasons. Wiring electricity in to 50bn devices would be a pain, unless they are electric anyway.
I've seen solar powered road photoradars, and road lights on some crossings between cities. Solar cells are on 2-3 meter pole, at +- 45 degree, and have sth like 0.5 square meter surface, and big box the size of car battery under the solar cell.
I guess it's more cost effective than draw the wires a few kilometers from the city.
Just curious, wouldn't a place that needs parking meters already be on the grid? Assuming we use parking meters to earn back the costs of building the parking lot or to stimulate the use of other forms of transportation than a car in that area.
On the other hand, having autonomous off-the-grid parking meters might be easier to install and maintain by a third party. Plus it allows you to start growing parking meters everywhere, even in the middle of nowhere. Let them pay!
The ones I've seen have been installed as higher tech replacements for traditional mechanical parking meters. Solar power means the old meter head can just be removed from the pole and the new one attached, with no need to worry about running underground electric service where none was before. I'm sure the savings in installation cost more than makes up for the addition of the solar panel.
It has been done before, at least according to the article, it appears that there already is competition in this market:
Arizona-headquartered Microchip Technology designs and builds a rival range of 32-bit "Pic" microcontroller, while California-based Atmel offers 32-bit "Avr" products.
But doing a bit of fact-checking, it might not be so simple.
32 bit uCs are nothing new. However PIC32s are large high performance devices with AES, Ethernet, USB etc built in depending on model[1]. They operate in a totally different area. You can use one to run a webserver and drive an LCD panel for example.
Atmel also offer 32 bit uCs in the form of AVR32 and ARM based parts.
I'm a bit surprised this hasn't been done before.
Can this chip be solar powered (I mean, obviously, with a small solar cell)?