Coded structure light is widely used for 3D scanning, and different coding strategies are adopted to suit for different goals. In this paper, three coding strategies are compared, and one of them is selected to implement a low cost structure light scanner under the cost of €100. To reach this goal, the projector and the video camera must be the cheapest, which will lead to some problems related to light coding. For a cheapest projector, complex intensity pattern can’t be generated; even if it can be generated, it can’t be captured by a cheapest camera. Based on Gray code, three different strategies are implemented and compared, called phase-shift, line-shift, and bit-shift, respectively. The bit-shift Gray code is the contribution of this paper, in which a simple, stable light pattern is used to generate dense(mean points distance<0.4mm) and accurate(mean error<0.1mm) results. The whole algorithm details and some example are presented in the papers.