CHAMP: Compliant Hook Arboreal Mobility Platform (Senior Thesis Project)

October 16, 2017 / Leave a comment

For my senior thesis project at WPI, myself and two colleagues (Rachael Putnam – RBE/ME and Mead Landis – RBE/ME) designed a tree climbing robot. I was in charge of designing and implementing the electronics and controls software. I was the most intense project I have ever worked on, both in terms of difficulty and potential impact. Here is our poster for project presentation day:

Here’s a video of the prototype climbing:

We did a blog during the project, here is the best post I wrote:

C TERM ELECTRONICS DESIGN NOTES

The report is massive, check it out here: https://digital.wpi.edu/concern/student_works/s4655j16f?locale=en

Soft-latching toggle switch with active reset circuit

September 19, 2017 / Leave a comment

This circuit aims to replace a traditional toggle switch for switching large amounts of current. Instead of the bulky and expensive traditional toggle switch, this circuit allows for a cheap pushbutton, and a few transistors and resistors to be used and have the same effect.

For my application, I wanted a way to have the circuit draw very little curren
t when in the off state, be able to be powered on with a pushbutton, and then turned off through software on the Arduino.
Here is the circuit diagram:

Here’s a video of the circuit in operation:

The code running on the Arduino is very simple:

int button = 3;
int led = 2;

void setup() {
  pinMode(button, INPUT);
  pinMode(led, OUTPUT);

  digitalWrite(led, LOW);
}

void loop() {
  if (digitalRead(button)) {
    digitalWrite(led, HIGH);
  }
}

int button = 3;

int led = 2;

void setup() {

pinMode(button, INPUT);

pinMode(led, OUTPUT);

digitalWrite(led, LOW);

}

void loop() {

if (digitalRead(button)) {

digitalWrite(led, HIGH);

}

StripPi – Software Demo, Roadkill Electronics

March 13, 2017 / Leave a comment

I’m constantly loosing the remote for my RGB LED strip lights, and I have a few days for spring break, time to get hacking. Here’s a demo and explanation video:

I don’t mention it in the video, but the cool part of this project is how the different processes communicate with each other. Rather than interacting with the different processes through pipes, or something like stdin, I’ve decided to use a TCP websocket server:

Processes on the device send RGB values to the Strip Server via a TCP packet. This very very easy to implement, and almost all of the hard work is taken care of via the socketserver module included in python3. This also allows for interactions with that main process (the StripPi Server process) to take place off of the Raspberry Pi as well. I plan on writing an Alexa integration for this project moving forward, and this should make that a lot easier.

The analog to digital conversion is handled by an MCP3008, exactly the same way as I did it here.

Thanks for reading, more soon.

Sound Supervisor

September 22, 2016 / Leave a comment

I wrote a page summarizing my HackMIT 2016 Project, check it out here!

RS485 Hardware Network 2 – Multi-Byte Communication

August 18, 2016 / 13 Comments

Edit: I don’t really make a point of saying it, but the common ground between the modules isn’t necessary.

Here’s a video of the software running on the boards.

So for this example, there are 4 bytes being transmitted from the master to the slaves.

Start of Transmission (0xDB)
ID of the slave to talk to
The type of command
The data that is transmitted

A transmission to set the pwm value of the green led on the slave with the ID 1 to 100 would be:

0xDB 0x01 0x01 0x64

1	0xDB 0x01 0x01 0x64

This is the schematic of the circuit for this example:

This is the code running on the master Arduino:

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;
int MAX485_Driver_Input_PIN = 11;
int MAX485_Driver_Output_Enable_PIN = 12;

#define NUMSWITCHES 3

int ID_switches[NUMSWITCHES] = {2, 3, 4};
int mode_switch = 5; 

byte IDs[NUMSWITCHES] = {1, 2, 3};

#define TXSIZE 4

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

byte target_node_ID;

struct transmission {

  byte start = 0xDB;
  
  byte ID;
  byte type;
  byte message;

  const int tx_size = TXSIZE;
};

void setup()
{
  software_serial.begin(9600); // begin software serial
  
  pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);
  digitalWrite(MAX485_Driver_Output_Enable_PIN, HIGH); // this disables Receiver Output Enable and enables Driver Output Enable
  
  for (int index = 0; index < NUMSWITCHES; index++)
  {
    pinMode(ID_switches[index], INPUT); 
  }
  
  pinMode(mode_switch, INPUT);
  
  target_node_ID = 0;
}

void loop()
{
  for (int index = 0; index < NUMSWITCHES; index++)
  {
    if ((byte)digitalRead(ID_switches[index]))
    {
      target_node_ID = IDs[index];
      break;
    }
  }
  
  transmission t;
  
  t.ID = target_node_ID;
  t.type = digitalRead(mode_switch);
  t.message = (byte)map(analogRead(0), 0, 1023, 0x00, 0xFF);
  
  byte message[TXSIZE] = {t.start, t.ID, t.type, t.message};
  
  software_serial.write(message, t.tx_size);
}

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;

int MAX485_Driver_Input_PIN = 11;

int MAX485_Driver_Output_Enable_PIN = 12;

#define NUMSWITCHES 3

int ID_switches[NUMSWITCHES] = {2, 3, 4};

int mode_switch = 5;

byte IDs[NUMSWITCHES] = {1, 2, 3};

#define TXSIZE 4

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

byte target_node_ID;

struct transmission {

byte start = 0xDB;

byte ID;

byte type;

byte message;

const int tx_size = TXSIZE;

};

void setup()

{

software_serial.begin(9600); // begin software serial

pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);

digitalWrite(MAX485_Driver_Output_Enable_PIN, HIGH); // this disables Receiver Output Enable and enables Driver Output Enable

for (int index = 0; index < NUMSWITCHES; index++)

{

pinMode(ID_switches[index], INPUT);

}

pinMode(mode_switch, INPUT);

target_node_ID = 0;

}

void loop()

{

for (int index = 0; index < NUMSWITCHES; index++)

{

if ((byte)digitalRead(ID_switches[index]))

{

target_node_ID = IDs[index];

break;

}

transmission t;

t.ID = target_node_ID;

t.type = digitalRead(mode_switch);

t.message = (byte)map(analogRead(0), 0, 1023, 0x00, 0xFF);

byte message[TXSIZE] = {t.start, t.ID, t.type, t.message};

software_serial.write(message, t.tx_size);

}

This is the code running on the slave Arduinos:

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;
int MAX485_Driver_Input_PIN = 11;
int MAX485_Driver_Output_Enable_PIN = 12;

int led_1_PIN = 5; 
int led_2_PIN = 6; 

unsigned long time = 0;  
unsigned long oldtime = 0; 
int state = 0;
int next_ID_button_PIN = 2;

#define NUMSTATES 3
int states[NUMSTATES] = {7, 8, 9};
byte IDs[NUMSTATES] = {1, 2, 3};

#define MESSAGELENGTH 3

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()
{
  software_serial.begin(9600); // begin software serial
  
  pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);
  digitalWrite(MAX485_Driver_Output_Enable_PIN, LOW);
  
  pinMode(led_1_PIN, OUTPUT);
  pinMode(led_2_PIN, OUTPUT);
  
  pinMode(next_ID_button_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(next_ID_button_PIN), next_ID, RISING); 
  
  set_LEDs();
}

void loop() // run over and over
{
  
  byte start_of_message = 0xDB;
  byte incoming_byte;
  byte message[MESSAGELENGTH];
  
  while (true)
  {
    if (software_serial.available())
    { 
      incoming_byte = software_serial.read();
      
      if (incoming_byte == start_of_message)
      {
        software_serial.readBytes(message, MESSAGELENGTH);
        process_message(message);
      }
    }
  }
}
 
void process_message(byte message[])
{
  byte system_ID = IDs[state];

  byte incoming_ID = message[0];
  byte incoming_mode = message[1];
  byte LED_brightness = message[2];
   
  if (incoming_ID == system_ID)
  {
    byte pin;
    
    if (incoming_mode == 0)
    {  
      pin = led_1_PIN;
    }
    else if (incoming_mode == 1)
    {
      pin = led_2_PIN; 
    }
    analogWrite(pin, LED_brightness);  
  }
}

void next_ID()
{
  time = millis();
  
  //soft debounce
  if (time - oldtime > 200) 
  {
    oldtime = time;
    
    state++;
    
    if (state >= (NUMSTATES))
    {
      state = 0;
    }
  }
  set_LEDs();
}

void set_LEDs()
{
  for (int index = 0; index < NUMSTATES; index++)
  {  
    if (index == state)
    {
      digitalWrite(states[index], HIGH);
    }
    else 
    {
      digitalWrite(states[index], LOW);
    }
  } 
}

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#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;

int MAX485_Driver_Input_PIN = 11;

int MAX485_Driver_Output_Enable_PIN = 12;

int led_1_PIN = 5;

int led_2_PIN = 6;

unsigned long time = 0;

unsigned long oldtime = 0;

int state = 0;

int next_ID_button_PIN = 2;

#define NUMSTATES 3

int states[NUMSTATES] = {7, 8, 9};

byte IDs[NUMSTATES] = {1, 2, 3};

#define MESSAGELENGTH 3

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()

{

software_serial.begin(9600); // begin software serial

pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);

digitalWrite(MAX485_Driver_Output_Enable_PIN, LOW);

pinMode(led_1_PIN, OUTPUT);

pinMode(led_2_PIN, OUTPUT);

pinMode(next_ID_button_PIN, INPUT_PULLUP);

attachInterrupt(digitalPinToInterrupt(next_ID_button_PIN), next_ID, RISING);

set_LEDs();

}

void loop() // run over and over

{

byte start_of_message = 0xDB;

byte incoming_byte;

byte message[MESSAGELENGTH];

while (true)

{

if (software_serial.available())

{

incoming_byte = software_serial.read();

if (incoming_byte == start_of_message)

{

software_serial.readBytes(message, MESSAGELENGTH);

process_message(message);

}

void process_message(byte message[])

{

byte system_ID = IDs[state];

byte incoming_ID = message[0];

byte incoming_mode = message[1];

byte LED_brightness = message[2];

if (incoming_ID == system_ID)

{

byte pin;

if (incoming_mode == 0)

{

pin = led_1_PIN;

}

else if (incoming_mode == 1)

{

pin = led_2_PIN;

}

analogWrite(pin, LED_brightness);

}

void next_ID()

{

time = millis();

//soft debounce

if (time - oldtime > 200)

{

oldtime = time;

state++;

if (state >= (NUMSTATES))

{

state = 0;

}

set_LEDs();

}

void set_LEDs()

{

for (int index = 0; index < NUMSTATES; index++)

{

if (index == state)

{

digitalWrite(states[index], HIGH);

}

else

{

digitalWrite(states[index], LOW);

}

RS485 Hardware Network 1 – Getting Started

August 1, 2016 / 6 Comments

For another project I’m currently working on, I need a way to control multiple microcontrollers in a multi-point, multi-drop network configuration. Luckily, we live in amazing times. As I write this, you you can buy a fully assembled breakout board for the MAX485 chip from Maxim Integrated for a mere $0.45 USD shipped from China.

I bought a 5 pack, here are some of the boards:

RS485 is an old protocol, but is the logical next step for devices I’m already communicating with via RS232. For this example, I’m using 4 Arduino boards of various types.

An Arduino Micro as the master
2 Slave Arduino Leonardos
1 Slave Arduino Pro Mini (5v)

Here is a video of the setup:

The schematic is really straightforward as well. The only tricky bit is that I’m using a software serial port on each of the Arduinos for ease of debugging. Here’s a schematic:

The code to acomplish this is really intuitive as well.

Here is the code for the master Arduino:

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;
int MAX485_Driver_Input_PIN = 11;
int MAX485_Driver_Output_Enable_PIN = 12;

int debug_led = 13;

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()
{
  Serial.begin(9600); // begin hardware serial
  software_serial.begin(9600); // begin software serial
  
  pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);
  digitalWrite(MAX485_Driver_Output_Enable_PIN, HIGH); // this disables Receiver Output Enable and enables Driver Output Enable
}

void loop()
{
  
  byte to_send = 0; // declare the byte to be sent to the slaves though, init as 0
  int rate;
  
  while (true) 
  {
    // invert the byte to be sent
    if (to_send == 1) to_send = 0;
    else if (to_send == 0) to_send = 1; 
    
    Serial.print("Sending: ");
    Serial.println(to_send);
    
    digitalWrite(debug_led, to_send);
    
    rate = map(analogRead(5), 0, 1023, 0, 1000);
    
    software_serial.write(to_send); // send our byte out to the MAX485
    
    delay(rate);
  }
}

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;

int MAX485_Driver_Input_PIN = 11;

int MAX485_Driver_Output_Enable_PIN = 12;

int debug_led = 13;

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()

{

Serial.begin(9600); // begin hardware serial

software_serial.begin(9600); // begin software serial

pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);

digitalWrite(MAX485_Driver_Output_Enable_PIN, HIGH); // this disables Receiver Output Enable and enables Driver Output Enable

}

void loop()

{

byte to_send = 0; // declare the byte to be sent to the slaves though, init as 0

int rate;

while (true)

{

// invert the byte to be sent

if (to_send == 1) to_send = 0;

else if (to_send == 0) to_send = 1;

Serial.print("Sending: ");

Serial.println(to_send);

digitalWrite(debug_led, to_send);

rate = map(analogRead(5), 0, 1023, 0, 1000);

software_serial.write(to_send); // send our byte out to the MAX485

delay(rate);

}

This is the code for the slave Arduinos:

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;
int MAX485_Driver_Input_PIN = 11;
int MAX485_Driver_Output_Enable_PIN = 12;

int debug_led_PIN = 9; 

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()
{
  software_serial.begin(9600); // begin software serial
  
  pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);
  digitalWrite(MAX485_Driver_Output_Enable_PIN, LOW);
  
  pinMode(debug_led_PIN, OUTPUT);
  
}

void loop() // run over and over
{
  byte k;
  
  if (software_serial.available() > 0) // make sure there is something to read
  { 
    k = software_serial.read(); // read in a single byte from the serial port    
    digitalWrite(debug_led_PIN, k); 
  }
}

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;

int MAX485_Driver_Input_PIN = 11;

int MAX485_Driver_Output_Enable_PIN = 12;

int debug_led_PIN = 9;

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()

{

software_serial.begin(9600); // begin software serial

pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);

digitalWrite(MAX485_Driver_Output_Enable_PIN, LOW);

pinMode(debug_led_PIN, OUTPUT);

}

void loop() // run over and over

{

byte k;

if (software_serial.available() > 0) // make sure there is something to read

{

k = software_serial.read(); // read in a single byte from the serial port

digitalWrite(debug_led_PIN, k);

}

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;
int MAX485_Driver_Input_PIN = 11;
int MAX485_Driver_Output_Enable_PIN = 12;

int debug_led_PIN = 9; 

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()
{
  software_serial.begin(9600); // begin software serial
  
  pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);
  digitalWrite(MAX485_Driver_Output_Enable_PIN, LOW);
  
  pinMode(debug_led_PIN, OUTPUT);
  
}

void loop() // run over and over
{
  byte k;
  
  if (software_serial .available() &gt; 0) // make sure there is something to read
  { 
    k = software_serial.read(); // read in a single byte from the serial port    
    digitalWrite(debug_led_PIN, k); 
  }
}

#include <SoftwareSerial.h>

int MAX485_Receiver_Output_PIN = 10;

int MAX485_Driver_Input_PIN = 11;

int MAX485_Driver_Output_Enable_PIN = 12;

int debug_led_PIN = 9;

SoftwareSerial software_serial (MAX485_Receiver_Output_PIN, MAX485_Driver_Input_PIN); // RX, TX

void setup()

{

software_serial.begin(9600); // begin software serial

pinMode(MAX485_Driver_Output_Enable_PIN, OUTPUT);

digitalWrite(MAX485_Driver_Output_Enable_PIN, LOW);

pinMode(debug_led_PIN, OUTPUT);

}

void loop() // run over and over

{

byte k;

if (software_serial .available() > 0) // make sure there is something to read

{

k = software_serial.read(); // read in a single byte from the serial port

digitalWrite(debug_led_PIN, k);

}

In subsequent posts, things will start getting more advanced. For now however this should be enough to start from scratch.

Thanks for reading.

UV Resin Curing Cabinet | Final Code, Schematic, Bill Of Materials and Demo

August 12, 2015 / 1 Comment

Here’s a demo of the finished system:

In the end, it all turned out really well. Painting it white and using a white print stand was a good insight, the light reflects around the box pretty well for how few LEDs are in use.

The software flow chart has changed slightly. I removed the speaker as it wasn’t loud enough and added software debouching for the pushbutton interrupt service routine. Here’s that most recent version:

The interesting parts of the code are the cookResin function as well as the main loop of the Arduino:

void loop() {
  digitalWrite(BUTTONLED_pin, HIGH); 
  displayStaticState(0);
  if (BPRESSED == true) {
    cookResin(14400);
  }
}

void cookResin(unsigned long MAXTIMER){
  unsigned long SECTIMER = 0;
  
  writeLCDLines("CURING TIME REM:", "H:MM:SS  -:--:--");
  
  fadeLEDs(1,1);
  
  while ((SECTIMER &lt; MAXTIMER) &amp;&amp; (BPRESSED)) {
    digitalWrite(BUTTONLED_pin, HIGH); 

    String part0 = String("H:MM:SS  ");
    String part1 = secToHuman(MAXTIMER - SECTIMER);
    String line1 = part0 + part1;
    lcd.setCursor(0, 1);
    lcd.print(line1);

    int DMILSECTIMER = 0;
    while ((DMILSECTIMER &lt; 10) &amp;&amp; (BPRESSED)){
      digitalWrite(BUTTONLED_pin, HIGH); 
      Alarm.delay(100);
      //Alarm.delay(1);
      DMILSECTIMER++;
    }
    SECTIMER++;
  }
  
  if (BPRESSED == false){
    //start of cancelled cure end
    
    displayStaticState(2);
    
    fadeLEDs(0,1);
    
    
    delay(1000);
    BPRESSED = false;
    
    //end of cancelled cure end
  } else {
    //start of successful cure end
  
    displayStaticState(1);
    
    fadeLEDs(0,1);
    
    delay(1000);
    BPRESSED = false;
    
    //end of sec cure end
  }
  
  return;
  
}

void loop() {

digitalWrite(BUTTONLED_pin, HIGH);

displayStaticState(0);

if (BPRESSED == true) {

cookResin(14400);

}

void cookResin(unsigned long MAXTIMER){

unsigned long SECTIMER = 0;

writeLCDLines("CURING TIME REM:", "H:MM:SS -:--:--");

fadeLEDs(1,1);

while ((SECTIMER < MAXTIMER) && (BPRESSED)) {

digitalWrite(BUTTONLED_pin, HIGH);

String part0 = String("H:MM:SS ");

String part1 = secToHuman(MAXTIMER - SECTIMER);

String line1 = part0 + part1;

lcd.setCursor(0, 1);

lcd.print(line1);

int DMILSECTIMER = 0;

while ((DMILSECTIMER < 10) && (BPRESSED)){

digitalWrite(BUTTONLED_pin, HIGH);

Alarm.delay(100);

//Alarm.delay(1);

DMILSECTIMER++;

}

SECTIMER++;

}

if (BPRESSED == false){

//start of cancelled cure end

displayStaticState(2);

fadeLEDs(0,1);

delay(1000);

BPRESSED = false;

//end of cancelled cure end

} else {

//start of successful cure end

displayStaticState(1);

fadeLEDs(0,1);

delay(1000);

BPRESSED = false;

//end of sec cure end

}

return;

}

Again, this all should all be explained by the flow chart. The full source can be found at the bottom of this post.

The circuit schematic hasn’t changed at all since this post, here’s a fritzing of what’s going on:

Super simple, basically a screen and a button. The parts to make this are here:

Assembly is super straight forward, if you’re trying to build one and have any questions, let me know!

Thanks for reading!

UV Resin Curing Cabinet | CAD Modeling And Physical Build and Installation

August 12, 2015 / Leave a comment

This past school year I too several classes related to 3D modeling. One class in particular, a class based around SolidWorks. I hadn’t really been able to use the software again, not having the tools to actually execute. MADE@MassChallenge really has the whole kit, 3D Printers, a 40W Laser Cutter etc. All the tools of a hackerspace as a part of my job. Here’s a “finished” model of the system:

Cure Cab Models

The frame is built out of:

.22in thick masonite painted black on one side
The frame is held together with a series of L brackets and machine screws from home depot
The front opening is secured with two metal hinges from home depot

There were a couple 3D modeled components as well:

The four feet

I ended up gluing these down with hot glue even though they have cuts for screws. In the end, it wasn’t worth it to use more screws and add more complexity.

The electronics enclosure

View post on imgur.com

There is a frosted acrylic sheet inserted in the top. One of the goals of this project was to show off the tech, and I think this does that quite nicely.

The knob assembly

View post on imgur.com

The knob has a stem that comes of the back and forces the hinge back, keeping the door closed. I wanted to try and keep things as simple as possible. The threads I modeled weren’t within tolerance. So I just glued the nut in place so the knob could rotate freely.

The print stand, for holding up the prints so they cure evenly

View post on imgur.com

It doesn’t make sense to have the prints just sit on the bottom of the frame. I also cut inserts that fit the inside of the print stand. This is so resin doesn’t cure to the print stand so it can be used many times while only needing to change the cardstock inserts.

Here are some more photos of the build process:

Cure Cab Build Photos

I’ll include the plans to build this whole assembly in the final post for this project once it’s all finalized.

UV Resin Curing Cabinet | Declaration and Software Flow

August 10, 2015 / Leave a comment

This project is the first of what I hope to be many in collaboration with the MADE@MassChallenge Hardware lab. The primary goal of this project is to speed up the time to delivery on prints coming out of the Formlabs Form 1+ SLA 3D printer using UV LEDS. Here’s a proof of concept of my circuit:

One of my tasks during my internship at MassChallenge was managing the queue of incoming models to be 3D printed on our 3D printers. Turnaround is often a pressing issue when doing this. It was often the case that teams had a deadlines or presentations that they needed parts for. Shaving even minutes off of the time from submission to receiving a fully processed part mattered quite a bit.

The Form 1+ is an amazing printer. If used correctly, the print quality can be much higher than the other 3D printer in MADE, a uPrint SE Plus by Stratysis; a printer almost 5 times the cost.

The post processing involved with the Formlabs has a steeper of a learning curve and leaves a lot of room for possibly destroying a part in the process.

The problem is not a fault of Formlabs, but rather a problem in the chemistry behind the resins used to create the parts. They are photopolymers, and need UV light to be cured. It is suggested that this be done through exposure to sunlight, but that takes quite a long time. I also have a sneaking suspicion that there are adverse effects of doing this, but I can’t prove any of that as of now but hopefully more on that later.

As this is a project that will be used by people other than myself, it is worth it to commit time and effort into the user experience. Atheistic should also be taken into account as this has to stand up next to the beautiful design of the Form1+. In short, a UV LED strand, a 3A switch, a power supply and a Light tight box could functionally do the trick, but in this case a polished design is as important as the functionality.

At this point, a push button switch, a rocker switch and a 16×2 Character LCD will be the UI. The software flow is as follows:

I’ll post the final code when I finish, but this chart is basically what the code running in the above video looks like.

Thanks for reading, more on the physical construction in the next post.

PiPlanter 2 | Plant Update and Daughter Board Migration

December 18, 2014 / Leave a comment

First, a video:

I’ve worked very hard since my last update to move all of the hardware that interfaces the Raspberry Pi with the plants (GPIO, ADC etc) from on board the Raspberry Pi using the GIPO to a daughterboard based around an Arduino.

This has been a lot of work to accomplish, but as of about a week ago, the transition was completed in it’s entirety and everything is operating totally normally without using any GIPO on the Pi.

This provides a portability for the platform that I haven’t been able to achieve so far. As the name of the project suggests, I’ve only used a Raspberry Pi to drive all of the hardware so far as well as do everything with the software. This transition opens up the possibility of using any computer running linux to be able to drive a PiPlanter if they have the board.

I’ve outlined the “PiPlanter Hardware Specification” in the current block diagram for the project. So if you have these parts, you can make a PiPlanter. The protocol for communicating between host computer and the Arduino is outlined here. I’ve decided to go with plain text serial using a rudimentary handshake to handle the communication. Pretty much all computers have a serial port, and the Arduino is very good at dealing with it as well.

One of the next steps that I take in this project would to be to design and fabricate PCB’s for specifically for this. This is certainly going to be a challenge for me, but it’s nothing I can’t handle. This also gives me the opportunity to maybe start selling PiPlanters which is exciting. I might need to change the name for obvious reasons…

Here are some nice photos of the updated setup:

All of the code and documentation for this version of the PiPlanter can be found here.

I am going on break from school from today, December 18th 2014 to on or around January 14th 2015. Now that the PiPlanter isn’t at my house, I can’t access the network remotely and make changes to the code. The next month will be a good stress test of the new daughterboard infrastructure. Hopefully it all goes well.

Thanks for reading!

esologic

Tag: electrical engineering

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PiPlanter 2 | Plant Update and Daughter Board Migration