原创 51的P1口驱动ULN2003的问题

哈哈~~~还是我手快~~~

抢在斑竹删帖前复制了网站地址,谢谢!!!

ZigBee vs Bluetooth

ZigBee is broadly categorized as a low rate WPAN, and its closest technology is Bluetooth.  A good bit of energy has been spent in analyzing whether ZigBee and Bluetooth are complementary or competing technologies, but after a quick look at the two, it can be seen that they fall a lot farther down the complementary side of the spectrum.  They are two different technologies with very different areas of application and different means of designing for those applications.  While ZigBee is focused on control and automation, Bluetooth is focused on connectivity between laptops, PDA’s, and the like, as well as more general cable replacement.  ZigBee uses low data rate, low power consumption, and works with small packet devices; Bluetooth uses a higher data rate, higher power consumption, and works with large packet devices.  ZigBee networks can support a larger number of devices and a longer range between devices than Bluetooth.  Because of these differences, the technologies are not only geared toward different applications, they don't have the capability to extend out to other applications.  As an example, for its applications, Bluetooth must rely on fairly frequent battery recharging, while the whole goal of ZigBee is for a user to be able to put a couple of batteries in the devices and forget about them for months to years.  In timing critical applications, ZigBee is designed to respond quickly, while Bluetooth takes much longer and could be detrimental to the application.  Thus, a user could easily use both technologies as a wireless solution in a PAN to suit all types of applications within that network.