Mark Matamoros ITP Blog

ITP Courses

Fall 2019

Spring 2020

Homemade Hardware

Week 3: Eagle Board Design. February 20, 2020.

INTRODUCTION

Within our third week of class, we students were introduced and granted instruction pertaining to the PCB design software Eagle. Futhermore, we began the creation of our circuits for the Marquee sign class project, where each student creates a circuit for their assigned letter.

For this week's assignment, we were tasked to finish our letter creation, abiding to the provided guidelines. The following links contain the required project files:

Project PDF

Project SCH

Project BRD

PROCESS

As mentioned, the creation of my PCB marquee letter began within class lecture, as our Eagle tutorial was handled in conjunction with our assignmnet. And regarding this instruction, we were introduced to various tools within the software, particularly focussing on components and the connections between these components.

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Upon finishing this particular design element in class, we began focussing on the board layout for our letters. To say the least, the initialized Eagle board setup for our circuit required some additional organization.

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After a bit of effort...

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...the finalized PCB design was finished.

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It must be noted that the utilization of the layer menu, turning on and off components of the board, allowed for smoother navigation within the environment. Additionally, various rearrangements of the components allowed for a design without the utilization of "vias."


Week 2: Tiny85 Jig and Interactive Project. February 13, 2020.

INTRODUCTION

This second week pertained to information and the utilization of the ATtiny85 microcontroller. Within the class session, we students setup an Arduino Uno as an ISP to flash a bootloader to an ATtiny85. Thereafter, we uploaded additional code to the ATtiny85 in a similar manner to how we would normally program an Arduino.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Regarding our assigment, we students were tasked to develop an ATtiny85 jig, where we would utilize a perfboard directly connected to an Arduino Uno. Furthermore, we were also tasked to utilize this jig to program any interactive setup with this particular microcontroller.

ATTINY85 JIG

As I cared to develop my jig in a manner directly reflective of the in-class lab, I began the process of mirroring the breadboard component connections to the perfboard. It must be noted that this approach pertained to the utilization of an LED, where I could quickly test if the ATtiny85 bootloader and programming instructions are functioning correctly.

To start, we aligned headers directly onto the Arduino Uno and soldered the perfboard on top of these headers. This approach allowed proper alignment of the necessary pins for the jig. Afterwards, the IC socket and ground cable were attached.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots
PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Thereafter, the power connection was handled.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

This step-by-step processed continued, attaching all capacitors, resistors, and LED to each pin.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots
PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots
PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Upon finishing the soldering, I attached the jig onto the Arduino for testing. Regarding this testing, I followed this step-by-step process: set the IDE's board selection to an "Arduino Uno", load the "ArduinoISP example", upload the "ArduinoISP example" to the Uno, set the Programmer to "Arduino as ISP", set the IDE's board selection to "ATtiny25/45/85", set the clock to "8MHz", utilize the IDE's "Burn Bootloader" function, and finally, utilize the "Upload Using Programmer" function. Upon following this process, I successfully uploaded a quick blinking script to the ATtiny85.

PCB with surface mounted components placed onto the solder paste spots

ATTINY85 INTERACTIVE PROJECT

For the interactive project component of the assignment, I chose to program the ATtiny85 with a potentiometer and an array of LEDs, where the former would trigger the flashing rate of the latter. Additionally, I planned to utilize a 9 volt battery for the battery source, requiring the utilization of a voltage regulator.

To begin the process, I began soldering the LEDs and associative resistors (330 ohms) to a small perfboard. Additionally, I ran stripped solid core wire across the positive end of the LEDs (in parallel) and across the resistors to establish the ground. Afterwards, I attached the IC socket to the perfboard.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots
PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Thereafter, the grounding pin was connected to the LEDs' resistors' ground.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Then, the voltage regulator with heat sink, turning 9 volts to 5 volts, was attached to the perfboard. Within this process, the regulator's ground and output voltage were also established to their coordinating areas.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Next, the potentiometer was soldered to the perfboard, with the voltage-out connected to the associtive socket pin. Additionally, the connection between the IC socket pin and LED array connection was established.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

Ground and power was then soldered to the potentiometer, followed with the connection between the 9 volt battery and the voltage regultor.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots
PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

And after uploading the code for the flashing LEDs, controlled by a potentiometer, I was met with success. It must be noted that I the length of the 9 volt's cables were shortened prior to testing.

PCB with applied solder paste
PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

CONCLUSION

I was very surprised about the simple nature of programming a microcontroller through the utilization of an Arduino and its IDE. I am looking forward to future work within this area.


Week 1: SMD Battery Charger. Arduino Components and Programming. February 6, 2020.

INTRODUCTION

For our first week of class, we students immediately jumped into the handling and untilization of SMDs through the building of a battery charger. Additionally, we were asked to review both Arduino circuit board components and programming through provided web links.

BATTERY CHARGER PROCESS

To begin the construction of the USB charger, we gathered each independent component. Thereafter, we placed these components onto a double sided piece of tape and labeled each one for organizational purposes. It must be noted that the provided circuit board was milled by the instructor. In addition to these electronic components, we were provided both a pushpin and dollop of solder paste, where the former would be utilized to spread the latter onto the circuit for soldering.

PCB, Surface Mounted components, and solder paste

Thereafter, we began the process of placing each component through the utilizaiton of prior mentioned technique. We first applied the solder paste to each area where the surface mounted component would be utilized. Then, we placed each piece onto the board, verifying the proper direction within the process. It must be noted that the IC for handling the charging process was not included in the prior work.

PCB with applied solder paste PCB with surface mounted components placed onto the solder paste spots

To handle the mentioned IC, we students utilized a Manncorp's SMT Place 2000 to manually place the component onto the board. Thereafter, we placed the assembled circuits onto a coffee warmer pad to bring the paste's flux to its melting point. Aftewards, a heating gun, set to 315 degrees, was utilized in a perpendicular manner to solder the components onto the board.

IC placement with Manncorp device Assembled circuit placed on top of coffee mug warmer

Upon finishing the last step, the board was tested with a rechargeable battery in conjuction with a USB power supply.

Finished circuit after soldering

ARDUINO REVIEW

After reading both listed pages regarding the Arduino components and programming, I became extremely grateful for the previously taken ITP courses revolving around electronics (PComp and Electronics for Inventors). Furthermore, my computer science background also assisted with the digesting of the Arduino programming component.

With that said, my comfort level pertaining to the means of programming a new ATMega328p is rather low, as I have yet to partake in this activity. This issue specifically revolves around the protocols (SPI + UART) and the programming setups.


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