tailieunhanh - McGraw-Hill- PDA Robotics - Using Your PDA to Control Your Robot 1 Part 6

Tham khảo tài liệu 'mcgraw-hill- pda robotics - using your pda to control your robot 1 part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | PDA Robotics Typical Optical Transceiver Circuit The optical transceiver logic can be implemented with discrete components for cost savings. Care must be taken in the design and layout of the photo-detect circuit due to the small signals that are being detected and their sensitivity to noise. MCP2150 Absolute Maximum Ratings Ambient Temperature under C to 125 C Storage C to 150 C Voltage on VDD with respect to V to V Voltage on RESET with respect to V to 14 V Voltage on all other pins with respect to V to VDD V Total Power Dissipation 1 . 800mW Max. Current out of VSS pin. 300 mA Max. Current into VDD pin. 250 mA Input Clamp Current IIK VI V or VI 0 VDD . 20 mA Output Claom Cu rrent I0K VO V or VO 0 VDD . uo mA Max. Output Current sunk by any Output mA Max. Output Current sourced by any Output mA Note 1 Power Dissipation is calculated as follows PDIS VDD x IDD - ỵ IOH ỵ VDD-VOH x IOH Z VOL x IOL NOTICE Stresses above those listed under Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Figure shows the physical layout of the MCP2150 chip used in PDA Robot. PIC16F876 PDA Robot s Microcontroller The PIC16F876 is used to send and receive commands from the robot to the PDA get analog readings from the range finder and switch the robot s motors on and off. I chose this chip because it is low cost very fast can be electronically erased flashed programmed and is readily available. 78 Chapter 5 The Electronics Units INCHES MILLIMETERS Dimension Limits MIN NOM MAX MIN NOM MAX Number of Pins n 18 18 Pitch p .100 Top to Seating Plane A .140 .155 .170 Molded Package Thickness A2 .115 .130 .145