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

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:

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

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

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

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!

PiPlanter 2 | Python Modules & Text Overlays

So in my last posting of the PiPlanter source code, the python script alone was 500 lines long. The intent with was to make things more modular and generic compared to the original version of the code that ran two years ago. Since the project has expanded a considerable amount since two summers ago, my goal of keeping everything short and concise isn’t really valid anymore so I’ve decided to split the code up into modules.

This improves a number of things, but it makes it kind of inconvenient to simply paste the full version of the source into a blog post. To remedy this, I’ll be utilizing www.esologic.com/source, something I made years ago to host things like fritzing schematics.

The newest publicly available source version can be found here: https://esologic.com/source/PiPlanter_2/ along with some documentation and schematics for each version to make sure everything can get set up properly. What do you think of this change? Will you miss the code updates in the body text of a blog post?

With all that out of the way, let’s talk about the actual changes I’ve made since the last post.

The first and foremost is that using Pillow, I’ve added a way to overlay text onto the timelapse frames like so:

Before

After

 

This was prompted by some strange behavior by the plants I noticed recently seen here:

I thought it was strange how the chive seemed to wilt and then stand back up and then wilt again, it would have been nice to be able to see the conditions in the room to try and determine what caused this. Hopefully I can catch some more behavior like this in the future.

Here is the new Image function with the text overly part included if you’re curious:

Now that I’ve got the PIL as part of this project, I’ll most likely start doing other manipulations / evaluations to the images in the future.

Okay! Thanks for reading.

PiPlanter 2 | Installing a 3rd Instance of the PiPlanter

Ten days ago I finished installing the third ever instance of the PiPlanter in a lab in the physics department at my college! I went with the the rack mounted design as I did this past summer, and am going to be growing Basil, Cilantro and Parsley as opposed to tomatoes. Here are some photos of the new setup:


There are a few major changes that come with this new instance. The first and foremost being the addition of LED grow lights. I’ll post a new version of the code with LED routines included when I think it’s polished enough. The second difference is that a tray of soil is being used as the growth medium for the plants as opposed to pots of soil. This will more than likely be the configuration I use moving forward. The final difference is the actual type of plants being grown. I’m moving away from tomatoes because there will be nothing to pollinate the flowers in the winter as well as the fact that I cook a lot and it will be neat to have spices that I can use on a day to day basis.

The first 10 days of growth has gone well. Here’s a video of them growing so far:

Thanks for reading!

PiPlanter 2 | Interfacing a Mikroelektronika CANSPI and an Arduino

The CANSPI board is a nice integration of the MCP2515 CAN Bus Controller and the MCP2551 CAN Bus Transceiver. To interface with these boards I’m using an Arduino Nano and the Seeed Studio CAN Bus Shield Library.

Here are some photos of the configuration, including the switch position on the CANSPI being used:

The wiring diagram goes as follows:

There are two parts of Arduino code, the sender and the receiver. The following code sends a sample piece of CAN data. Attach a potentiometer to A0, and twist it to see the differences in data in the receive code:

The following prints all CAN data received to the serial monitor:

Twist the potentiometer and see the change in data to see that it’s all working:

Thanks for reading!

Parsing Serial Data Sent To Arduino

I use this code constantly. It basically packages serial data for strtok_r to split into pieces paced on predefined deliminators. Each bit of data is separated by a “,” and the end of the set of data is a “.”

If you send in a string like:

You can split it into three varaibles that equate to those different values. In this case:

The Variable x would equate to 10.

Here’s the code:

Here’s an example.

Say you have a serial device hooked up to your softserial port and in inputs “10,50,100.” to the arduino to be split up. If you want to set each of these numbers to separate integers and then print them to the serial console, you’d do it like this.

PiPlanter 2 | DIY Lite Version Release!

Since I returned to college the PiPlanter has been running without me having to do any maintenance on it at all. The plants are still alive and growing and all processes associated with the PiPlanter are still going. I figure now is a good a time as any to bring together all of the work I’ve done to till this point in one concise post.

This does NOT mean I’m done working on future versions of the PiPlanter. I’ll hopefully write another post stating goals for the future sometime soon. Now onto the build tutorial.


 

The Hardware

 

First, the hardware of the project. A good place to start would be the parts list:

In the previous version of the PiPlanter, I didn’t have a concrete parts list for the project. Hopefully I’ll be able to keep this spreadsheet updated if the project changes. A lot of these components are mix and match, you could use pretty much any pump (The math for volumetric pumping is done with this pump) or any tubing or any power supply that can do 12v and 5v. A computer PSU would work great as well.

This is the hookup guide for the system:

(Thanks to tamps for the help!)

The two sets of header blocks are to be replaced by the moisture sensors, and the motor replaced with the pump.

For a physical configuration, I’ve found through multiple times doing this that mounting it on a wire rack works the best as seen here:

Edit (10/19/2014) Here is the same group of plants two months later without any direct human interaction. They grew from the light in the window and used up all of the water in the reservoir which was totally filled before I left.

To distribute the water to the plants, attach the vinyl tubing to the outflow of the pump and seal off the other end of the outflow tube. Run the tubing along the plants and drill holes wherever you’d like the water to exit.

You’ll also need to install the camera module in the Pi and point it wherever you’d like the frame of the photo to be.

 

The Software

As a preface, I’d like to at first say that this software was written entirely by me. I’ve never had any formal training in programming of any kind, so if there are obvious flaws with my code please let me know. That being said, I’ve found that this system is very effective and has worked for me and kept my plants alive for months.

All of this runs off of a base install of raspian on a raspberry pi model b.

There three major parts to the software. First, the prerequisites:

You’ll need to enable SPI on your Pi in order to use the MCP3008 ADC. Do this by running the following commands:

Comment out the spi-bcm2708 line so it looks like this:

Then run this to make it more permanent.

And finally reboot your Pi with:

Then the php code that renders the pChart graph. More details for installing pChart here and officially here.

And now the star of the show, the python script:

Before running, make sure you make the following changes to the script:

You’ll need set up access to twitter API’s, seen here. You’ll need to input your information about your twitter app into into 331-334 of this script.

You’ll need to input information about your YouTube account on line 429

On line 473 you’ll need to input your mysql information.

 

Output Demos

The PiPlanter is very connected. It renders graphs of data, takes images and renders timelapse videos.

Here’s a standard tweet showing the plants:

Here’s a tweet showing a day’s worth of data in  a  graph render:

Here’s a tweet showing a week’s worth of data in a graph render:

Here’s a timelapse video of three days:

Follow @PiPlanter_Bot for updates on my plants.

That’s pretty much it! Please feel free to modify this code for any use you’d like.

All of my research on this project can be found here.

Thanks for reading, and please leave a comment if you like my work!

PiPlanter 2 | Updating Dependencies

In addition to the directions in this post on getting the ADC working, the following must be run to get the current version of the PiPlanter up and running.