0 Introduction
With urbanization, traffic from people's lives continues to expand, replace the fuel cars and bikes electric bike manufacturer greatly increased the popularity of the efficient use of power resources, and promote the healthy development of the national economy. Electric bicycle powered by electricity, riding does not produce pollution, without prejudice to air quality. From improving the way people travel, environmental protection and economic conditions and other factors together, present and future of electric bikes have a broad space for development. DC motors used in electric bicycles into the brush motor and brushless motor two. One relatively simple brush motor control. But its easy to brush wear caused maintenance workload is relatively large, relatively short life and other shortcomings. The brushless DC motor itself is not easy to wear and tear parts, motor, long life, small repair and maintenance work. However, brushless DC motor uses electronic commutation principle work, the control process is much more complicated than brushed motors, so the quality control requirements are much higher.
Currently used in electric bicycle brushless DC motors are three-phase motors, electrical angle of 60 ° and 120 ° two. Number of motor poles is 18 very much, there are 16 very, very, etc. 20. The motor controller according to Hall electrode position feedback to control the corresponding power-driven tube opening or off, rotating magnetic field generated in the stator, the rotor drive motor rotation.
In order to determine whether the normal operation of the brushless controller, which is detected and turn the brake function is normal, to determine the controller's point of view is 60 ° or 120 °, and the winding A, B, C phase position signals a, b, correspondence between c and correctly connect the controller and motor, a lot of testing instruments are analog circuits, so the result is not very accurate, but also the circuit is very complex and costly. Design uses STCl2C5410AD microcontroller as control chip, greatly simplifying the hardware circuit to software programming to achieve.

l Introduction to brushless motor controller electric cars
From the peripheral device and the main controller chip (or chip) components. Peripheral devices are some of the functional devices, such as the implementation, sampling, etc., they are resistors, sensors, bridge switching circuit, and supporting microcontroller or ASIC device to complete the control process; also known as single-chip micro-controller is integrated in a chip to memory, language has transformed signal decoder, sawtooth generator and pulse-width modulation circuit and be able to control power switching circuit is turned on or off, control power through the square-wave tube of the turn-on time to control the motor speed drive circuit, integrated input and output ports, etc., consisting of a computer chip. This is the electric bicycle intelligent controller.
Controller design quality, features, functions used in microprocessors, power switching devices and peripherals circuit layout, is directly related to vehicle performance and operational status, also affect the performance and efficiency of the controller itself. Different quality of the controller, used in the same car, with the same group with the same battery charge and discharge status, sometimes in driving ability on the show quite different.
Currently, controllers used in electric bicycle is basically the same circuit or close. Brush and brushless DC motors were powered by the PWM pulse width modulation speed control method, but use the drive circuit, integrated circuits, switching power transistor circuit and certain related functional differences. Components and circuit differences, constitute the performance of different controllers.

2 System Hardware Design
To determine whether normal brushless controller, measuring various parts of the controller output signal is standard, and can receive the motor, turn the brake signal, to determine whether the controller needs to achieve to achieve its function, the control system to detect device and the brake to turn to whether there is a stable 5 V voltage output, determine the controller's point of view, and control lines to determine the Hall and its corresponding phase sequence and phase sequence are the same motor power. Only the position sensor signal and winding A, B, C are properly connected to the motor running. Figure 1 shows the overall design of the circuit diagram, the system uses STCl2C5410AD microcontroller as the main control chip. STCl2C5410AD MCU technology is the production of single-crystal macro clock / machine cycle (1T) of the chip, high-speed, low power, a new generation of super immunity 8051, fully compatible with traditional instruction code 8051, but the speed of 8 to 12 times, the internal reset circuit dedicated MAX810 integrated, 4 PWM, 8 way high-speed 10 bit A / D conversion, a special occasion for the strong interference motor control.
2.1 bridge rectifier circuit
Work is needed because the controller is DC, so it is necessary to add a rectifier circuit. System chosen is the single-phase bridge rectifier circuit. This circuit as long as four diodes connecting the mouth to "bridge" structure, it has the advantage of full-wave rectifier circuit.
2.2 brake and turn the signal detection
Potential changes in the level of the brake signal, the controller identify the state of Electric Vehicles is in braking, in order to determine whether the controller to the motor power supply basis. As long as the brake and turn the output of the signal received STCl2C5410AD microcontroller A / D conversion end P16 and P17, will be able to detect the output is normal.
2.3 controller to determine the angle and phase sequence
Shown in Figure 2, A first winding voltage determine the output of the two optical coupler connected to the controller's final stage, in parallel with the A's up and down tube, when the A's on the tube turns, A high-voltage output make the following optocoupler conduction. To output a voltage value, the microcontroller through STCl2C5410AD A / D conversion end P11 port to the microcontroller; when the A's under control turn-on, A low-voltage output, so the above coupler conduction, which outputs a voltage value, By STCl2C5410AD microcontroller A / D conversion end P10 port to microcontroller. B and C the same connection with the above. Output when the output is not directly, but through opto-isolation after the output for the following reasons: one-way transmission of the signal optical coupler, the input and output full realization of the electrical isolation, the output signal has no effect on the input side, anti-jamming strong, stable, non-contact, long life, high transmission efficiency.
3.1 overall design flow chart
Overall design flow chart shown in Figure 3.
Measurement controller input impedance, when it is greater than 10 Ω for normal, or short-circuit power supply input. Turn to, brake handle, the power side of the Hall to ensure that the output voltage is greater than the detection of 4.5 V. Controller to determine the angle and phase sequence of the truth table to judge according to brushless and testing, only the controller point of view to determine the following example.
3.2 Programming the controller to determine the angle
As can be seen from Table 1 when a, b, c are taken, "0", the controller when the angle of 120 °, A, B, C do not turn up and down the tube; and 60 ° when the controller is on the tube A and B under the MOSFET, which would then according to a, b, c are taken to "0", A, B, C of the output signal to determine the angle of the controller. Flow chart shown in Figure 4.

4 Conclusion
System design using STCl2C5410AD microcontroller as a control chip, the circuit is simple, accurate measurement, good to meet the electric car brushless motor controller detects the need to detect and brake controller then turn to the side is normal, to determine control the angle, the Hall and its corresponding control phase sequence and motor power are the same phase sequence. Hoped that the design of the application in the future be better improved and perfected.