Prototype: Fritzing and Breadboarding – Spring 2016

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Posted by: Luis Valdivia(Project Manager)
Written by: Kevin Nguyen(Electronics and Controls)

 

Table of Contents:

  • Introduction
  • Fritzing
  • Breadboarding
  • Protoboarding

 

Introduction:
It is important to prototype the schematic before sending it to the fab house. This is to ensure that the PCB would work the first time since PCB fabrication takes a lot of time and money.

 

Fritzing:
To start, a fritzing diagram is drawn on the Fritzing software. The Fritzing software allows us to draw out the connections of the physical components. This makes it easy to see where every component goes.

 

Fritzingfinalized

Fig 1.1 Fritzing Diagram

Breadboarding:
After finishing the fritzing, the circuit can be implemented onto a breadboard. Since the servo driver on our PCB does not come in through-hole packages it cannot be inserted into the breadboard. Once the buck converter is fully connected with all the supporting components, it must be tested for proper functionality. A power supply was used to test the breadboard. Setting the power supply to 14.8V to simulate the LiPo battery, we were able to acquire a 4.94V output.

 

testing out the buck

Fig 1.2 Testing the Buck Converter

 

Protoboarding:
Once the circuit is verified to be working. The components are transferred onto a protoboard to make things more compact and easy to use. The protoboard could be mounted onto the quad to be used for testing while waiting for the PCB to come in.

 

youngbuck

Fig 1.3 Protoboard

 

Conclusion:
The circuit schematic must be prototyped to make sure the circuit works before sending it off to be fabricated. The prototyping process for the circuit schematic includes fritzing, breadboarding, and protoboarding. This gives the extra benefit of being able to use the prototype while waiting for the PCB. These extra steps are needed to save time and money.

Spring 2016 RoFi: Project Summary

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Christopher Andelin (Project Manager)

Mario Ramirez (Systems Engineer)

Qui Du (Manufacturing Engineer)

Andrew Laqui (Electronics and Controls Engineer)

Henry Ruff (Electronics and Controls Engineer)

Table of Contents

Executive Summary

Program Objectives & Mission Profile

By Christopher Andelin (Project Manager)

RoFi is the fifth prototype from Project Biped.  It is a self-contained, bipedal robot that uses accelerometer feedback to balance. It has 12 DOF (degrees of freedom) and can walk around while avoiding obstacles using an ultrasonic range sensor. A small Android tablet in RoFi’s head provides the brains and an Arduino Mega provides the hardware interface.

Spring 2016 RoFi: Preliminary Design Documentation

The Design

The figures below are our mechanical design and layout of RoFi.

 

Exploded View2

Exploded View

back view

Rear View

Full body

Right Side View

side view

Left Side View

 

Project Features

Some key features of our design include:

  • Redesigned head
  • Battery Backpack
  • Larger batteries for longer run time
  • SMT PCB / Microcontroller
  • Periscope provides vision
  • RoFi must walk a figure 8 obstacle course

Some innovation of our design include:

  • Mouse pad for shoes
  • Designer glasses box for prototype head due to its ability to be shaped and retain form
  • Servo locks are used to secure loose servos

 

System Design

System Block Diagram

By Mario Ramirez (Systems Engineer)

The Block diagram shows our system broken into sub-systems and how each sub-system is connected to complete the entire system.  Pins for the Atmega chip can be verified through our interface definitions.

block diagram

System Block Diagram

 

Experimental Results

Accelerometer / Gyroscope

By Andrew Laqui and Henry Ruff (Electronics and Controls Engineers)

The accelerometer/gyroscope MPU-6050 found here was tested by implementing the test code found here and reading the raw values that were printed through the Arduino IDE. Detailed instructions on how to use those raw values can be found here in Henry Ruff’s blog post.

accelerometer-gyroscope_compressed

Accelerometer / Gyroscope

 

Ultrasonic Sensor

The ultrasonic sensor SEN136B5B was used on RoFi in order to detect and avoid objects. Various tests were performed in order to determine the range for which the sensor can detect. An in-depth explanation of these tests can be found here. The table below details the various angles that the sensor detected an object.

table

Ultrasonic Sensor Data

 

Servo Driver

The servo driver PCA9685 found here was tested because originally, an Arduino UNO was going to be used in order to reduce the size of the Arduino. Ultimately, rather than using an Arduino UNO, an ATmega1280 was implemented on the custom PCB design in order to accomplish this size reduction. A detailed description of how to servo driver was tested can be found here.

servo driver_compressed

Servo Driver

 

Experimental Results

By Mario Ramirez (Systems Engineer)

Below is our table of experiments completed.

mario experiments

Experimental Results

 

Torque Testing

An analysis of the maximum torque needed to move each mass is done to insure RoFi’s servos can provide enough torque before stalling. Further information can be found here, https://www.arxterra.com/spring-2016-rofi-torque-report/.

This table shows the torque needed for each mass compared to the stalling torque of each servo.

torque calc.

Torque Calculations

 

Center of Mass

Center of Mass simulation was done to visualize RoFi’s center of mass with the new head design.  The center of Mass is represented by the black and white circle. Further information can be found here, https://www.arxterra.com/spring-2016-rofi-center-of-mass-report/.

center of mass 1

Center of Mass Side View

center of mass 2

Center of Mass Front View

Subsystem Design

Interface Definition

By Mario Ramirez (Systems Engineer), Andrew Laqui  and Henry Ruff (Electronics and Controls Engineers)

Below is our pin mapping for the ATmega 1280 chip.

interface definitions 1a

Interface Definitions 1a

interface definitions 1b

Interface Definitions 1b

interface definitions 1c

Interface Definitions 1c

interface definitions 1d

Interface Definitions 1d

 

Custom PCB / Microcontroller Design

Custom PCB Design

By Andrew Laqui and Henry Ruff (Electronics and Controls Engineers)

The beginning of the custom PCB design began with taking a look at how messy the physical breadboard was. Due to the number of servos (12), the wires needed to be carefully attached and handled in order to not have any wires disconnect.

messy cables_compressed

Messy Cables

Using the free software Fritzing, a digital diagram of the breadboard was constructed. Various libraries were added to the original software because the free software did not provide a few of the required parts. Those libraries can be found in the links to the Custom PCB Blog below.

fritzing

Fritzing Diagram

Next, using the free software EAGLE, a schematic was constructed including all of the components that will be used on RoFi according to the interface definitions. The schematic was then used to determine the finalized layout for the actual PCB. More information for the PCB Layout can be found in Qui Du’s PCB Layout blog post.

PCB schematic

PCB Schematic

PCB Schematic 2

PCB Schematic Continued

finalized PCB layout

Finalized PCB Layout

 

Active Balancing of RoFi During Movement

By Henry Ruff (Electronics and Controls Engineer)

A large challenge for RoFi was the utilization of the MPU-6050 Accelerometer/Gyroscope while it was performing its active walking cycle. Because RoFi had to traverse a threshold, incline, and perform a figure-8 on such, it became very time-consuming and difficult to successfully replicate in separate run-throughs. As such, utilization of the MPU-6050 would have been able to make RoFi’s walking more reliable and easier, however, we were unable to successfully implement in. Instead, the following blog post elaborates on relevant efforts.

Spring 2016 RoFi: Research and Implementation of the Accelerometer/Gyroscope

 

PCB Design

By Qui Du (Manufacturing Engineer)

I created the PCB layout once I received the PCB schematic from the Electronics and Controls Engineers. More detail about our PCB Design could be found here.

 

Soldering the PCB

After generating Gerber files and ordering the PCB components, I sent the Gerber files to class president Ryland Watts. One and half weeks later, we received the PCB board and PCB components. I soldered the PCB board with help from the class president Ryland Watts and the manufacturing division manager Juan Mendez. Here is the result of PCB board before and after soldering.

PCB

PCB Before Soldering

PCB After Soldering

PCB After Soldering

 

Hardware Design

My design decreases the size of the head and feet. Below is the completed SolidWorks 3D modeling of RoFi.

mechanical design

Complete RoFi Design

Detailed information about the design could be found here

After generate the STL files and making STL repair using netfabb Basic, all parts were ready to print. Here is the final result of RoFi.

complete rofi_compressed

Complete RoFi

 

Software Design

Software Block Diagram

By Mario Ramirez (Systems Engineer)

Here is a flow chart of our software.  The grey boxes are scripts written to handle the telemetry.  This code is given to you by Hill.  Blue squares represent the different subroutines for our code.  The red boxes represent the type of pin each sensor or actuator is connected to.  The orange squares represent the name and number of the pin each sensor or actuator is connected to.  The yellow boxes represent our sensors and actuators.  Green boxes represent what the user is controlling based on the software.

software block diagram

Software Block Diagram

 

Verification & Validation Test Plan

Verification and Validation are based off requirements that can be found here, https://www.arxterra.com/spring-2016-rofi-preliminary-design-documentation/

Note: The Pass / Fail and Percentage Completed columns is our teams opinion and not that of the customer.

verification and validation req.1a

Verification and Validation Req.1a

verification and validation req.1b

Verification and Validation Req.1b

verification and validation req.2a

Verification and Validation Req.2a

verification and validation req.2b

Verification and Validation Req.2b

verification and validation req.2c

Verification and Validation Req.2c

verification matrix 1a

Verification Matrix 1a

verification matrix 1b

Verification Matrix 1b

verification matrix 1c

Verification Matrix 1c

 

Project Update

Work Breakdown Structure

By Christopher Andelin (Project Manager)

Below is our work breakdown structure.

CDR WBS

Work Breakdown Structure

 

Resource Reports

Mass Report

By Mario Ramirez (Systems Engineer)

Project allocation is based off of the maximum mass the servos would be capable of moving before stalling.

mass report

Mass Report

 

Power Report

Project allocation is based off of a 15 minute run time.  This report assists in calculating what ratings you need for the batteries.

power report

Power Report

 

Budget Report

By Christopher Andelin (Project Manager)

Note: Our project cost does not include the PCB / Microcontroller and the components because our President bought them.

cost estimate

Project Cost

 

Schedule

Below is our project schedule.

View post on imgur.com

Schedule Summary

Here is my assessment on our overall progress:

  • Mechanical Design 100% 
  • PCB / Microcontroller Design 100% 
  • Repaired issues with loose frame 90%
  • Improved running time 100%
  • Periscope lens 100%
  • Polyfuse SMT 100%
  • Organize cables 100%
  • Moving parts hazard 0%
  • Walking in a circle on flat surface 100%
  • Surpass leveled surface to inclined surface threshold 100%
  • Walking in a circle on inclined surface 25%
  • Figure 8 obstacle course 30% (leveled surface circle only)

My overall assessment is that we are about 80% complete.

 

Burndown Chart

Our burndown chart dips in the last week due to getting the printed parts and PCB / Microcontroller implemented into our design.  We still need to complete the figure 8, hence the reason why we are behind schedule.

burndown chart

Burndown Chart

 

Concluding Thoughts

Since it is the end of the semester, I have some suggestions for future RoFi teams:

  • Get approval for all purchases – Due to time constraints, our team was in a rush to get parts in to begin implementation.  We focused our attention on completing our mission objective without considering our customers expectations.  It is important to complete the objective as well as pleasing the customer.
  • Replace servos with better quality – We had servo issues throughout the semester. We always had a spare servo in hand due to the unpredictability of servo failure.
  • Make RoFi lighter – The servos would spasm causing RoFi to fall.
  • Lower the center of mass – Due to RoFi being so top heavy, it was difficult implementing walking on an inclined surface.
  • Avoid using Robot Poser – Robot Poser only worked on one of our team members laptops and we never found out why.  Robot Poser was also difficult to get it to start.  You may have to open task manager at times and close programs, plug and unplug the Arduino cable and the battery; I felt like we had to jump through hoops to get it to work.
  • Implement the ultrasonic sensor, accelerometer/gyroscope and cordless walking – Due to customer request, we focused a lot of our attention getting RoFi to walk the figure 8 obstacle course and neglected other features.
  • Get RoFi asap – We had to do a lot of documentation throughout the semester, we did not get to work on RoFi until about one month into the semester.
  • Choose team members wisely – I was fortunate to have a great team but keep in mind that students have other classes and work to attend to.  Interview students and select members that have time, transportation and money.
  • Project Manager – As Project Manager I had a lot of paperwork in the beginning of the semester. Work slowed down in the third month, so I dedicated a lot of my time getting RoFi to walk and assisted the engineers where I could.
  • Be cautious of free 3D printing – Verify that the quality of the 3D printing material is to your liking.
  • Understanding the customer – Realize that the customer has multiple projects and classes and will claim things were said or were not said that you may need to address.  Communicate and verify all concerns with the customer, student teacher and president.
  • Update Mission Objective – Our mission objective said that the incline was 8 and 6 degrees;  we measured the incline and it varied from 14 to 7 degrees.  The room was also a burden to work in because the room was popular for labs and lectures.

 

Resource

Project Video

Bonus Videos

www.youtube.com/watch?v=96UEVOszRBs

Files

The following Google Drive contains useful resources for future RoFi teams, https://drive.google.com/drive/folders/0B_v74PMhdCbKSXVPQ285ekZEX28.

Spring 2016 RoFi: Research and Implementation of the Accelerometer/Gyroscope

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Christopher Andelin (Project Manager)

Mario Ramirez (Systems Engineer)

Qui Du (Manufacturing Engineer)

Andrew Laqui (Electronics and Controls Engineer)

Henry Ruff (Electronics and Controls Engineer)

Research and Implementation of the Accelerometer/Gyroscope

By Henry Ruff (Electronics and Controls Engineer)

Note: All files referenced without additional links can be found in the RoFi Spring 2016 Google Drive, https://drive.google.com/drive/folders/0B_v74PMhdCbKSXVPQ285ekZEX28.

RoFi’s movement is somewhat inconsistent, and as such, it is unreliable in being able to perform the same exact frames that it was able to perform from a previous trial; a solution to this inconsistency is the implementation of the MPU-6050 accelerometer/gyroscope, as an ideal albeit very optimistic task. The  MPU-6050 would allow RoFi to be able to balance itself through normal runs, on different surfaces and inclines, all using the same walking code.

In order to be able to start any of these possibilities, research was done on implementation of the MPU-6050. The following Arduino guide is used to obtain raw, readable values with the device.

http://playground.arduino.cc/Main/MPU-6050.

However, this is not a usable format. Instead, Jeff Rowberg had created files for utilization of the readings from the MPU-6050. The tutorial used in being able to work with these files is found here, http://diyhacking.com/arduino-mpu-6050-imu-sensor-tutorial/. Just in case, the necessary Arduino libraries that are used can also be found with the rest of the RoFi files.

Please note, a common complication that can arise in compiling this code is if any Arduino libraries get included before the initial comments in Rowberg’s code. The desired types of values can be toggled by commenting and uncommenting different modes of output.

 

For RoFi’s purposes and to optimize the code as much as possible, I have trimmed down Rowberg’s code to only what might be used, and this version is shown in the “MPU6050Code.txt” file found in the Google Drive. This file is meant to provide the chunks of Rowberg’s code that should be placed into RoFi’s normal walking code generated from Robot Poser, and instructions for which are found within the file itself.

Now that the code has been integrated into RoFi’s walking code, it can theoretically be used to assist in its balancing. The main considerations that we were able to come up with in doing this were as follows:

  • Previous semesters had only utilized the MPU-6050 while RoFi was stationary.
  • As RoFi is walking, the MPU-6050’s data would need to be referenced between each frame of motion.
  • RoFi’s head does not stay parallel to the ground while walking, instead it turns in every direction except rotation about the z-axis. This means the gyroscope is fine for the z-axis, but complex for the other two. If RoFi’s head can be kept parallel, this problem can be circumvented.
  • With the values being read, they can be compared to an expected set of values for RoFi’s normal movement. However, this would need a very large file containing ideal gyroscope values, and the Arduino is not able to reference external files, and there is the concern of limited memory on the Arduino Mega.
  • RoFi’s head movement is too erratic and jerky to use the accelerometer for comparisons with how our current walking code performs. (This can be observed in walking videos.) Similarly, this prevents the gyroscope by comparing values that are being read to each previous value.
  • An acceptable range of variation cannot quite be determined with RoFi’s current movement, to be used in making RoFi balance itself.
  • RoFi’s balance while walking is not as simple as moving one servo a few degrees, rather, most frames of movement utilize several servos, and even one degree on each can overthrow its balance.

With these considerations, the progress we were able to make is simply this suggested code “MPU6050Control.txt”, (in the Google Drive) for future semesters and a guideline for potential ways to use the MPU-6050 to actively balance RoFi during motion.

Spring 2016 3D SMD: Verification Test — Working Area

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By Christine Vu (Missions, Systems, and Test) and Henry Nguyen (Electronics and Control)

Working Area Test

Working area is defined by the area that includes  PCB to assemble, reel feeders, and IC tray. To verify that our design meets the size criteria for working area, a test will be conducted to calculate its parameters.

Requirements

Section 1 EE400D Assembly

The SMD pick and place machine shall pick up and place down all SMT components provided by any EE400D PCB up until the end of Spring 2016.

Section 1.1

Working area must be within 12.2”x15.35”(310mmx390mm) based on the Makeblock X-Y

Plotter Robot Kit.

Section 1.1.2

Surface to hold PCB shall be smooth with dimensions tolerances to be ±.001″, parallelism to .001″, and flatness to .001″ (TCI Precision, 2005).

Section 1.1.3

All pick and place processes shall begin at the bottom left corner of the PCB.

Section 1.1.4

All moving cables using RJ25 connectors shall have a minimum bend radius of 10x its diameter (Telecommunications Industry Association, 2001).

Section 1.2

Pick and place SMD machine shall change the orientation of each SMT component before placement.

 

Applicable Tools

Equipment Type Name (Brand) Tolerance
Mitutoyo S/N 12519090 Caliper 0.001”
Measuring Tape Stanley 33-425 Powerlock 25-Foot by 1-Inch Measuring Tape +/- 3%

Procedure

  1. Attach Z-axis and all other subsystems.
  2. Using X- and y-axis limit switches, move the X-axis and Y-axis at the maximum and measured the allocated work area.
  3. Generate an EAGLE file by placing capacitors on each corner of the design.
  4. Convert to GCode and verify the dimensions of the PCB Outline.
  5. Using another Gcode file, test the rotation movement of an SMT component by rotating about 180 degrees in 45 degree increments.

Results

The following table indicates the parameters for our working area. The orientation of the EAGLE file parameters are 4” along the X-Axis and 3.2” along the Y-Axis. It is important to note the minimum reel feeder distance from the X-Axis

Working Area Parameters Distance (in.)
X-Axis 12.6
Minimum Reel Feeder Distance from X-Axis rods 7.034
EAGLE Outline 4.001 x 3.2002

Rotation movement for procedure 5 can be done using G-Code programming operations. Since our rotation movement is using a stepper motor, we decided to half-step the orientation for 45 degrees.

Rotation Coordinate Degrees
B5 45
B10 90
B15 135
B20 180

Conclusion

Our working area measurements indicate that each subsystem is able to fit in our X-Y Plotter. The rotation of each SMT component can be done using G-Code software.

Spring 2016 3D SMD: Verification Test — Reel Feeder

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By Christine Vu (Missions, Systems, and Test) and Henry Nguyen (Electronics and Control)

Reel Feeder Design

To verify the reel feeder design has the correct function, a test will be conducted to determine its parameters and design.

Requirements

Section 4

The SMD pick and place machine shall have four 8mm reel feeders and one IC tray.

Section 4.1

All SMT resistors and capacitors shall remain in cut-tape of the reel feeders until the vacuum nozzle is ready to pick up the component.

Section 4.1.1

All reel feeders shall be installed on the working area, 12.2”x15.35”(310mmx390mm).

Section 4.1.2

Bracket to hold cut-tape of the reel feeders shall be higher than 0.04″.

Section 4.1.3

All motors used to peel off cut-tape of reel feeders must rotate 360°.

Section 4.2

IC tray shall store all IC chips required for one PCB assembly.

Section 4.2.1

IC tray shall be installed within working area, 12.2”x15.35” (310mmx390mm).

Applicable Tools

Hardware:

Reel Feeder

Micro Servo FS-90

Equipment Type Name (Brand) Tolerance
Mitutoyo S/N 12519090 Caliper 0.001”

Procedure

  1. Install reel feeder to the aluminum surface. Attach reel with SMT components.
  2. Install the IC tray to the working area.
  3. Install micro servo to reel feeder bracket. Servo wheel shaft shall be placed at an angle of approximately 45°. Record Servo wheel angle.
  4. Attach Z-axis and move the X-Y-axis motors to a component. Measure the clearance around the Z-axis. Record the clearance tolerance, which includes the distance around both the reel feeder and IC tray. Measure the height of the IC tray.
  5. Operate the micro servo by turning 360°. This requires timing of the speed of the micro servo and must be determined in the Arduino Code. Record this time.
  6. Determine initial measurement of the reel on the reel feeder. Record this measurement
  7. With the cut-tape attached to the micro servo wheel shaft, reel in the cut-tape.
  8. Observe the elevation of the reel feeder. Record the height of the reel feeder.

Results

 

Parameter Can the vacuum nozzle reach? [Y/N]
Microservo rotation >360° Y
Distance between Nozzle and X-Axis Limiting switch  (in.) 3.011 Y
Distance between Nozzle and cut-tape (in.) 0.515 Y
Distance between Reel Feeder component and X-Axis Limiting Switch (in.) 4.161 Y
Bracket for microservo height (in.) 4.214 Y
Distance between microservo and end of cut-tape (in.) 2.975 Y
Distance between vacuum nozzle and IC tray (in.) 4.021″ Y

The angle of the cut-tape:

Capture

It was observed that increasing the angle at which the cut-tape was reeled required more force due to the way we changed the angle. If we changed the angle to approximately 60 degrees, it required us using the back bracket attached to the reel feeder and more force to pull the cut-tape.

Placement tolerance between the edge of reel feeder closest to the X-Axis and the nozzle:

4.161” – 3.011” = 1.15”.

Conclusion

Based on these parameters, we were able to conclude that our placement of the reel feeder system will be reached by the vacuum nozzle. Maximum rotation is more than 360°; however, the cut-tape would not stay in place of the servo if the wheel is holding too much of the cut-tape. Increasing the angle at which the cut-tape is allowed to turn resulted in ripping the cut-tape.

 

 

UFO PCB Layout Spring 2016

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Posted by: Luis Valdivia (Project Manager)
Written by: Juan Mendez (Manufacturing Engineer)

Table of contents
Introduction
Wire Traces
Building the PCB

 

Introduction

Our PCB was laid out after the schematic that was provided by our electronics and control engineer. The size of the board was set to roughly 2.5 by 2.5 inches so it can fit on the UFO frame. The screw holes were spaced out roughly 1.8 inches apart from each other. The reason this was done was to have the ability to put the multiwii on top of the pcb or vice versa. Each component was organized based on the size of the component and following recommendations from the spec sheets. Components such as the battery alarm pin headers were spaced out because alarm was approximately 3 mm thick.I isolated it from everything else so spacing would not be an issue. The servo pin headers were spaced out evenly at roughly 2 mm apart so spacing would not be an issue when being connected to the servos. The buck converter was placed close to the input voltage pads. I placed ground vias on the thermal pad of the buck converter since it was recommended by the spec sheet. Components such as the capacitors and diodes were placed next to switching output pins in order to reduce magnetic noise. The output capacitor C3 was placed as close as possible to the inductor and diode to reduce noise and to increase efficiency. Resistors “R2” and “R3” were placed close to the Feedback pin as mentioned in the data sheet. Capacitor “C1” was  placed close to the enable pin and to ground as recommended on the data sheet. The pin headers for the bluetooth connections were put in the bottom so they would not get in the way of anything else similarly to the battery alarm. Lastly the Servo driver was placed close to the servo pin headers and the lightshow pin headers were added on the top left corner of the board.

 

PCBFINAL

Figure 1.1 .BRD layout of PCB on Cadsoft Eagle

 

Wire Traces

In order to make sure that mistakes were not repeated from previous semesters, we used a trace width calculator from 4PCB to calculate how thick the traces had to be. Each servo was going to be drawing a max of two amps. The board thickness was roughly 1 ounce. According to the trace calculator, the traces had to be roughly 2.03 mm thick in order to draw 2 amps. Other traces were either signal or did not draw enough current and were set to be no more than .5 mm thick.

 

Tracecalculator

Figure 1.2 Trace width calculator

Building the PCB

After laying out the PCB, we submitted our Layout and schematic to be ordered along with our parts list. With the help of our class president Ryland Watts, we were able to mount on the surface mounting parts using a reflow station in IEEE. We mounted on  the small resistors and capacitors first since they could have been done at once with the reflow station that we were using. Since the capacitors were bigger, we had to mount them on one at a time only because if we tried doing them all together, the heat of the reflow station would not reach the pads, therefore not mounting them properly. Once those components were on the PCB, we soldered on the pin headers. One issue we experienced was that the inductor ended up being bigger than we anticipated so the pads on the PCB were too small to mount on the inductor using the reflow station. To fix this, with the help of our electronics and control engineer, we soldered on the inductor and were able to mount on the inductor. Once the PCB was built, it was ready for testing.

pcbstogether

Figure 1.3 PCB before and after all parts have been attached

To view a video of the PCB Buck Converter stepping voltage, Click here

To view a video of the PCB Servo Power Supply, Click here

Reference:

To view the schematic for this PCB check out our blog post: PCB Design: Schematic – Spring 2016

Verification: Requirement 1.4 – Project Budget

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Posted by: Luis Valdivia (Project Manager)
Written by: Anthony Becerril (Mission, Systems, and Test Engineer)

 

Following the Verification and Validation Matrices, this post follows the level 1 requirement 1.4 – project budget remaining below provided funds. This also satisfies its corresponding level 2 requirements if applicable.
To meet the requirement, we had to finalize and approve a budget that was at most or less than the provided funding which was $167 U.S. Dollars. The budget was updated via our resource reports, specifically the project budget. A reimbursement form was created and provided receipts. This was approved by the customer and forwarded to the College of Engineering Electrical Engineering Department to finalize the process. Supporting documentation is provided below and we have completed and passed this requirement.

 

20160419_074842

Figure 1.1 Receipt of hobby people purchase (battery and safety bag)

paypal

Figure 1.2 Online receipt of hobbyking.com purchase (two Electric Ducted Fans)

Additional Resources:

Previous Blog Post: Verification and Validation Matrices (Spring 2016)

Verification: Requirement 1.3 – Federal Aviation Administration, Unmanned Aircraft Systems, and California State University, Long Beach College of Engineering Compliance

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Posted by: Luis Valdivia (Project Manager)
Written by: Anthony Becerril (Mission, Systems, and Test Engineer)

 

Following the Verification and Validation Matrices, this post follows the level 1 requirement 1.3 – Federal Aviation Administration (FAA), Unmanned Aircraft Systems (UAS), and California State University, Long Beach College of Engineering (CSULB COE) compliance. This also satisfies its corresponding level 2 requirements if applicable.
To meet the requirement, compliance of FAA, UAS, CSULB COE rules and regulations had to be done. That consisted of registering the quadcopter officially under the FAA which included a UAS registration of 5 U.S. Dollars, acknowledgment of safety guidance, and its own registration number FA3C74WXLT. Supporting documentation is provided below and we have completed and passed this requirement.

$5

Figure 1.1 Registration Fee along with expiration

requirementstofly

Figure 1.2 User must follow these safety guidelines while flying aircraft

REGISTRATION

Figure 1.3 UFO Quadcopter MUST display registration number while flying. We attached the registration number to the ducted fans.

Additional Resources:

Previous Blog Post: Verification and Validation Matrices (Spring 2016)

Spring 2016 3D SMD: IC Tray

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By Nasser Alsharafi (Manufacturing)

The Custom 3D Printed IC Tray

The custom 3D printed IC tray is designed to house 21 evenly spaced different sized common IC components. One of the largest and most desired ICs we will be using is the ATMega32U4 IC. This IC is the standard for which we will calculate our pressure and rotation of the A-Axis. The different sizes are placed in order or square mm from largest to smallest respectively. The size of the IC must be less than 0.3 inches from the aluminum table. This is due to the optimization of the machines speed. Therefore the total height of the IC is 0.25 inches. The well sizes of the 21 part compartments are 0.1 inches deep. The entire IC tray is 4.45 inches long by 3.75 inches wide. The IC tray has four holes that allow the IC tray to be attached to the aluminum table.

The compartments fit components the following components:

  • SO8 x3
  • SO14 x3
  • SO16 x3
  • ATMega32U4 x3
  • Standard 14 mm x 14 mm square ICs TQFP x3
  • SO28 x3
  • Standard 12mm x 12 mm square ICs TQFP x3

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 Fig 1 ATMega32U4 Dimensions

Figure 2. Above shows the dimensions of the ATMega32U4 IC. The D/E dimension shows the size in mm of the IC. The IC is approximately 12mm x 12mm from pin to pin.

 

Spring 2016 3D SMD: Reel Feeder Bracket

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By Nasser Alsharafi (Manufacturing)

Table of Contents

The Reel Feeder

The Reel Feeder shown above is a major component of the pick and place machine. This component is fully automated, and has custom fabricated aluminum parts. It is made up an aluminum base, four SMD part reels, four servos, four legs, and one axle, 4 spacer drums.

The base has four cut channels that are 8mm wide. There are four reels that are positioned on an axle that spins freely. This forces the component tape in the reels to be channeled through the 8mm grooves. There are additional legs that are bolted to the base that hold the axle and the SMD part reels.

The Base

The base is (10.0 inches long   x 4.0 inches wide) the base has four channeled grooves spaced by 8mm across. The base has a tape guard that spans the entire width this is to ensure that the tape stays in the grooved channel.

 

The Reels

The four reels made of plastic that are positioned on an axle that spins freely. The reels spin and dispense the parts onto the aluminum table. The part reels are 5 inches in diameter. Two 5-inch long legs bolt into the base hold up the reels and axle. The reels hold SMD component tape. A plastic cover seals the tape. The size of the components in the SMD tape are very small at 0402.

The Custom Servo Platform

The four servos are mounted onto an adjustable platform by 8 screws. There are four spools attached to the servo, which contain the tape as it wraps up the plastic. The platform is set at 45 degrees from the base. This allows the plastic cover to be pulled off the SMD part tape, and advances the tape simultaneously. The device has legs for the custom bracket that are mounted by 2 screws to the base. The custom servo platform is fabricated from a rectangular piece of aluminum. The servos placed in a 0.9 inch cut out section of the aluminum are evenly spaced out the entire length of the 4.0-inch platform.

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