Pathfinder Generation #4

Pathfinder S’17 Final Blog Post

By Martin Diaz (Project Manager) Edgardo Villalobos (Solar – Design and Manufacturing Engineer) Anthony Dunigan (Chassis – Design and Manufacturing Engineer) Renpeng Zhang (Electronics and Control Engineer) Abdullah Albelbisi (Missions, Systems, and Test Engineer) Executive Summary By Martin Diaz (Project Manager) Program Objective 1. Articulating custom solar panels which are able to track the sun […]

HC-SR04 Ultrasonic Sensor Test

By Renpeng Zhang HC-SR04 range test Table Range HC-SR04 was tested Code /* * HC-SR04 testing code * Connect Vcc to 5V * Connect Gnd to Gnd * Connect Trig to pin 9(PWM) * Connect Echo to pin 10(PWM) */   // defines pins numbers const int trigPin=9; const int echoPin=10;   // defines variables […]


By Renpeng Zhang Chassis Schematic Schematic Description For the chassis eagle schematic, I choose to use two PCA9685 I2C expanders because one doesn’t have enough PWM pins for all our needs. We also used six VNH2SP30 motor driver for our motors. We use the PWM input from the I2C to the PWM pin in the […]

Solar Cell Wire Layout

By Edgardo Villalobos Wire layout out for the solar panels. Top View Bottom of panels 1. 2. 3. Top Level    

Wheel Forces Calculations

By Anthony Dunigan Back of the envelope calculations for wheels and electronic slip differential. Requirements Level 2 Requirements In order for the project to move forward in our Level 2 requirements numbers 8 and 9. We need to gather calculations based on our 6 in (0.0762m)  wheel diamater. Constants and Variables r = radius (m), […]

Solar Current Sensor Experiment

(Written By: Edgardo Villalobos – Manufacturing/Solar Panel) Using INA3221 current sensor breakout boards to measure current and voltage of a battery. INA3221 current sensors will be implemented in project to isolate voltage of each solar cells. Overview This project requires current sensors in order to measure the current running through the solar cells. We are […]

Stepper Motor Control

By Renpeng Zhang Demoing control of a stepper motor. Overview In this demo, I tested the 28BYJ-48 stepper motor with the ULN2003 stepper motor driver. I used one Arduino for the control of the stepper motor. Since it’s recommended to use an external power source, I just used another Arduino solely for the purpose of […]

Solar Panel Voltage Calculations

By Edgardo Villalobos Calculations to find what voltage and current the solar cells need to provide to charge the battery in 8 hours. Voltage Battery  Solar Panels need to be able to charge a 12-Volt, 7-Ah (10-Ah) battery Rule of thumb  Rule of thumb: Solar Panel Voltage = Battery Voltage x 1.5       […]

Encapsulation Trade Off Study

By Edgardo Villalobos Study on types of solar cell encapsulation.   PLEXIGLASS Plexiglass provides a lightweight, about 3 lbs per 8 sq. ft. with a 0.065 thickness, anti-reflective surface and is classified as a scratch resistant surface. Although plexiglass is virtually impossible to break and scratch resistant, it can scratch much easier than glass. If […]

Chassis Fritzing Diagram

By Renpeng Zhang Fritzing Diagram for Chassis. Diagram Description Based on the interface definition, I created the fritzing diagram for the chassis part of the pathfinder. It consists of the Arduino Leonardo with two HC-SR04 ultrasonic sensors. It has the HC-05 bluetooth module connected to the Arduino through the TX and RX pins for the […]