tailieunhanh - McGraw-Hill- PDA Robotics Part 8

Tham khảo tài liệu 'mcgraw-hill- pda robotics part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | PDA Robotics 8. 8-pin DIP switch 9. 18-pin DIP IC socket Note the PIC16F876 is using two one cut down 10. 6-post mm DIP headers 11. MHz crystal 12. MHz crystal 13. 1-pin header for analog input It is good practice to check the conductance after soldering a component to the board. This ensures that electricity will flow between the points on the circuit and with little resistance. If conductivity is poor it means that the solder joint is poor and should be redone. To check for conductivity set the multimeter to RX 1 KQ and touch one probe on the solder weld and the other on a trace to which it is connected. Figure Enlarged view of left side of main board. 118 Chapter 6 Building PDA Robot Figure Enlarged view of right side of main board. The needle on the meter should spike to the right showing zero resistance. Figure shows the meter set to RX 1 KQ with the leads crossed and the needle to the far right indicating that there is no resistance and that the meter is working properly. Figure shows testing the conductivity of the solder connections. Figure Setting the meter for conductivity testing. 119 PDA Robotics Figure Testing the solder connections on a prototype circuit. To ensure a good solder joint keep the tip of the iron clean. Buy high-quality fairly thin solder and ensure that the iron is hot. Clean the tip after soldering two or three joints. Placing and Soldering the Motor Controller Components Figures to show the placement of the parts on the motor controller circuit. The following numbers correspond to those on the motor controller circuit board. Ensure that the diodes are oriented correctly as shown in the figure. 1. Molex mm 2P headers with ramp connects to Molex .156 wire connectors 2. .1 UF capacitors or higher 3. 4007 746 diodes 4. 6-post mm DIP headers 5. L298N dual bridge driver .