Building Robots Part 12 docx

Motor TRANSISTOR ONE TRANSISTOR THREE POWER + POWER + POWER - POWER - current flow current flow current flow Motor TRANSISTOR TWO TRANSISTOR THREE TRANSISTOR FOUR POWER + POWER + POWER - POWER - TRANSISTOR ONE ENABLE DIRECTION AND gate AND gate Inverter AND gate Inverter AND gate DIRECTION Enable Motor 1 Direction A Direction B Motor Power M1 Enable Motor 2 Direction A Direction B M2 Motor Ground Block Diagram of the L293 Motor Driver Chip Pin 1 Pin 2 Pin 7 Pin 3 Pin 6 Pin 8 Pin 9 Pin 10 Pin 15 Pin 11 Pin 14 Pins 4,5, 12,13 Pin 16 Logic Reference Voltage H-Bridge Motor Driver Circuit H-Bridge Motor Driver Circuit [...]... information, but the data itself is transmitted on two uni-directional wires 4 B.5 THE SERIAL LINE CIRCUIT U7/74HC132 12 13 U8 11 +5V 4053 12 AX 13 AY 2 BX 1 BY 5 ctlA 1 1 A 14 ctlB 1 0 B 15 R2/47K +5V C3 4700pF C1 10µF RP3/1K 9 CX CY 7 Vee 3 205 ctlC C 4 Transmit Data 6811 Port D1 RP3/1K INH 6 LED12 Receive Data SER XMIT C2 10µF 6811 Port D0 U7/74HC132 1 3 2 RS232 TxD R3 100K SER RCV LED11 R6/2,2K RS232 RxD... purposes, the amplier is kept at full brightness, but there may be applications where this feature is useful +5V U10 2 1 4 6811 E clock 6811 Port A6 U12/74HC04 5 6 Timer Output 2 CLR CLKA CLKB 14 CLR 15 CLKA 12 CLKB 3 QA 5 QB 6 Q C 7 Q D 13 QA 11 QB 10 Q C 9 Q D U12/74HC04 9 8 R14/1K U11 pin 6= motor power pin 4= motor ground U11/LM386 3 R15/1K 5 390 2 LED5 (red) RP5/22K RP5/22K 6811 Port A7 + - Timer Output... that is blinking on and o at a particular rate The GP1U52 sensor is tuned to 40,000 Hertz (40 KHz) In TV remote applications, a data stream is then generated around the 40 KHz carrier frequency The signal consists of bursts and gaps of the 40 KHz transmissions For the 6.270 application, the 40 KHz carrier is used to tranmit a square wave of relatively low frequency (100 or 125 Hz), as shown in Figure... This sequence of actions implements an orderly shutdown sequence B.6.3 The Power-Up Delays To make sure that the 6811 does not corrupt memory while it is being powered on, the 6811 is made to enter a particular mode that does not access external memory Also, the 6811 is hardware-protected from writing into the RAM immediately after power is turned on After power has normalized, the user can press the... keep the memory \alive" for periods of up to thirty minutes when the system is powered o and batteries are removed B.6.2 The Power-O Interrupt Diodes D1, D2, and D3 provide isolation amongst the three parts of the circuit:  the memory's power supply  the microprocessor's power supply  the power-o interrupt circuit This isolation is necessary to ensure clean transition of the power-o interrupt circuit... Figure B.21: Sharp IR Sensor Decoding IR-Encoded Square Wave Divide-by-50 Counter ’390 6811 E clock 2 MHz Modulated 40 KHz Power Amp Enable IR light emitter Modulation Ctrl Brightness Control (100 or 125 Hz) Figure B.22: Block Diagram of Infrared Circuitry B.7 THE INFRARED TRANSMISSION CIRCUIT 211 divide-by-fty function by ganging two of the divide-by-ve counters and one of the ip- ops The IR control... memory and for the microprocessor circuit) retain charge for a brief period after power is 208 APPENDIX B 6.270 HARDWARE switched o The diodes prevent this charge from \ owing backward," and allowing one part of the circuit to power another When power is switched o, the power-o interrupt signal immediately goes low However, system capacitors (mostly, C13) will keep the microprocessor powered up for a... Beacon Figure B.24 shows the schematic for the IR beacon Each infrared LED has a visible LED in series with it so it should be easy to ascertain that the device is transmitting APPENDIX B 6.270 HARDWARE 212 RP8/47Ωx4 RP9/47Ωx4 + - LED23-30 Red LED's LED31-38 MLED71 IR LED's Figure B.24: Infrared Beacon Circuit infrared light properly The resistors act as current-limiters, limiting the amount of current . E1 6811 Port E3 6811 Port E2 2 4 2 10 10 2 12 10 3 1 6 3 11 1 14 3 14 3 11 1 6 3 3 1 4 3 2 16 8 816 12 13 15 9 7 11 15 15 1 6 7 3 16 9 1 5 19 9 2 1 5 413 12 13 12 5 4 13 8 14 7 17 4 18 3 1 2 2 2 2 11 11 1. 11 D4 1010 10 D3 99 9 D2 10 3 8 3 3 9 5 22 2 21 4 20 12 4 13 2 14 5 15 1 16 12 17 15 18 14 19 13 23 1 24 12 25 15 26 14 27 13 11 5 2 413141 5121 6 76 76 7 Host ComputerRobot Board signal ground Robot. 10µF +5V U7/74HC132 R2/47K C3 4700pF U7/74HC132 R3 100K R4 10K R6/2,2K LED11 RP3/1K +5V LED12 RP3/1K 6811 Port D1 6811 Port D0 12 5 1 3 7 14 15 11 10 11 12 13 4 RS232 TxD RS232 RxD 1 2 13 2 6 9 3