The design and implementation of an embedded paper currency characteristic data acquisition system

The paper currency characteristic data acquisition system is a real-time subsystem of bill acceptor system based on ARM and uClinux, but uClinux can not meet the real-time requirement of the data acquisition system. After considering the characteristic of uClinux and the hardware of the data acquisition system, a method for improving the real-time ability of the data acquisition system is proposed by reference the architecture of RTLinux. A real-time control layer is introduced into this system to control hardware interrupts. The paper currency characteristic data acquisition task is put into kernel level as a high priority task of the real-time control layer, and uClinux is regarded as a low priority task of the control layer, and they are scheduled by the real-time control layer. In experiments, the improved paper currency characteristic data acquisition system can meet the real-time requirement.