Earlier at the construction site in the forehead by steel plate touch, n900 have no hardware equipment can detection range? If there is a software development can from her own head, TouQian, head, objects distance from less than set distance, automatic alarm?? The last time I didn't pay attention to steel, be touched,,,,,,,, this thing similar car reverse infrared sensing, how many meters distance automatic speech broadcast

早前曾在建筑工地上被钢板碰了额头，n900有没硬件设备可以探测距离？如果有可否开发个软件在离自己头上 ，头前，头后，有物体距离小于自己设定的距离，就自动报警呢？？我上次就是没注意钢板，被碰了，，，，这个 东西类似汽车倒车红外感应，距离多少米都自动语音播报

There's a proximity sensor, but I think that's far too short range for what you're suggesting. There's an infrared transmitter, but I don't think there's a receiver at all (and it's not in a convenient location to use the camera as a receiver either).

Please avoid duplicate threads.

Could an admin merge this with http://talk.maemo.org/showthread.php?t=81534 ?