51 single-chip design to shoe code matching instrument

1. Principle shoe code matching device, using the principle of ultrasonic ranging. By using ultrasound to encounter the characteristics returned to the obstacle, the time calculation of the ultrasonic discharge and the returned time calculation is calculated to determine the distance from the obstacle and the ultrasonic module. The inherent size of the shoe code matching device is known. When the foot is placed, the size will change the size of the distance to obtain the feet using a known distance to change the change, and then the correct shoe code is obtained by the conversion of the size and distance (this Use standard shoe code). 2. The desired components (a treasure can buy a very cheap) · Ultrasonic module 1 · TPYBOARD V102 board 1 piece · four digital tube 1 · micro USB data cable 1 · DuPont line several 3. Ultrasonic module work Principle (1) Triginal ranging with IO port Trig, gives a minimum of 10us high level signals. (2) The module automatically sends 8 40 kz square waves, automatically detects whether there is signal to return. (3) There is a signal returns, and a high level is output through the IO port ECHO, and the high level continues is the time of ultrasonic waves from transmitting to the return. Test distance = (high level time * sound speed (340 m / s)) / 2. As shown in the figure, VCC is 5V power supply, GND is a ground line, TRIG trigger control signal input, and Echo reclaimed signal output and other four interfaces. 4. Control four-digit digital tube display number (1) 1, 2, 3, 4 is "bit" pin for control which bit display. (2) A, B, C, D, E, F, G, and DP (h) are "segments" pin, usage, and 1 digit tube consistent, used to display specific values. Digital tube (bit) TPYBOARD V10X development board 1x32x43x54Gnd (shoe code matches less than four bits, this foot pull low) Digital tube (segment) TPYBOARD V10X development board AX6BX7CX8DY9EY10FY11GY12DP (h) leaves blank (this pin is a decimal point control foot Hanging out) 5. Wiring diagram 6. Source code Import Pyb From Pyb Import Pin From Pyb Import Timer From Machine Import SPI, PIN Trig = PIN ('' x2 ', pin.out_pp) Echo = PIN ('' x1 ', pin.in) Num = 0 Flag = 0 Run = 1 DEF Start (t): Global Flag Global Num IF (Flag == 0): Num = 0 Else: Num = NUM + 1 DEF Stop (T): Global Run IF (Run == 0): Run = 1 START1 = Timer (1, FREQ = 10000, Callback = Start) STOP1 = Timer (4, FREQ = 2, Callback = STOP) SIZECC = [35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47] # 280-47 -5 While True: IF (Run == 1): Trig.Value (1) Pyb.udelay (100) Trig.Value (0) While (eCho.value () == 0): Trig.Value (1) Pyb.udelay (100) Trig.Value (0) Flag = 0 IF (eCho.value () == 1): Flag = 1 While (echo.value () == 1): Flag = 1 IF (Num! = 0): #print ('' Num: '', NUM) Distance = NUM / 1000 * 34000/2 Print ('Distance' ') Print (Distance, '' mm '') CC = (int) ((Distance-215) / 5) IF CC "0: CC = 0 ELIF CC "12: CC = 12 Print (SIZECC [CC], '' CC '') Flag = 0 Run = 0, read the full text