Written By

Charles Banuelos MFG DM

Muhannad Al Mohamed E&C DM

Previous tests

The color sensor placement in relation to the PCB is very important. The distance testing that will be occurring will tell what is the best distance to place the color sensors on the PCB. The sensor placement will determine whether the robot will run smoothly along the hedges and not stop every couple of centimeters. These tests will also determine how big the PCB will be since the tests will show whether an I2C multiplexer is needed.

Matt Shellhammer conducted tests in relation to the the adafruit color sensor and forwarded me the results. The data states the distances to detect three different colors(Brown, White and Green). The code also tests the horizontal distances for the same three colors. The study states that the optimal distance vertically for all three colors is between 1mm and 2cm. The horizontal for all three colors should be between 3mm and 1.4cm. The second color sensor(BH1745NUC) will be tested in the same manner as this test.

Written By Charles Banuelos MFG DM

 

Testing Color Sensors

 

The adafruit TCS34725 color sensor had only one fixed address. This resulted a problem for the projects of the Robot Company since most of them are planning to use two color sensors. The problem with communicating with a specific device using I2C (Inter Integrated Circuit) protocol is that I2C have to address a device with a unique address and since using two adafruit TCS34725 color sensors have the same address, it would result a conflict of data being sent by those sensors when the micro-controller is trying to talk to one of them. Therefore, another solution was presented by Pr. Hill, which was to use the color sensor Thomas Forman is using. Thomas’ BH1745NUC  color sensor can be adjusted to have two different addresses. By connecting the “ADDR” pin in one of the BH1745NUC ICs to VCC and the other BH1745NUC “ADDR” pin to ground would result having two color sensors with two different addresses.

Written By Muhannad Al Mohamed E&C DM

Planned Testing

The color sensor shield that has two BH1745NUC Color sensing ICs needs to be tested. The connections of the pins should be tested using inputs preferably by a 3DoT board. If a 3DoT board were not available an Arduino Uno would be used with taking caution to the voltage to be 3.3V. Implementing Address checking codes should check the addresses of the two BH1745NUC Color sensing ICs. Data should be read and values of colors should be detected. Thomas Forman has ordered parts for his color sensor shield and since he is using the same BH1745NUC Color sensing IC, we would be able to test the parts.

After checking that the color sensor shield is working correctly, sensing colors from the maze should be tested.

Update: 11/29/2017

Parts, stencils, and solder have been ordered and received during the Fall Break. Charles Banuelos, Muhannad Al Mohamed, and Melwin pakpahan are currently fabricating the Color Sensor Shield. After fabrication is completed Charles Banuelos and Muhannad Al Mohamed will test the Color Sensor Shield. Soldered parts will be visually checked if they were placed correctly without any bridges or misplacement. Connecting the Color Sensor Shield to the 3DoT board should be tested by visually verifying that the pins of the shield are actually connected to the front header of the 3DoT board. Also, by applying an Arduino code to find specific I2C addresses using the 3DoT board, the two different I2C addresses should be checked. The Color Sensor Shield would be tested on how it can actually measure colors (intensity of different colors).

Written By Muhannad Al Mohamed E&C DM