Site has been down

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You’re currently reading this via a virtual server running on top of this server, which is hosted out of my residence in southern Maine. For the most part, I generally enjoy the challenges and obstacles that come with self-hosting this website but it becomes very very annoying in cases where there is physically nothing I can do. Take these past two days for example.

Storm!

Sometimes it snows a foot in an hour and the power goes out for a few days. Not much I can do about it, sorry for the inconvenience. If it’s any consultation, Twitter isn’t hosted out of their parent’s house and you can follow me there where I typically post if my site is up or down.

Thanks for reading!

PiPlanter 2 | Python Modules & Text Overlays

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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

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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

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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!

Blink out IP address for Raspberry Pi using Python

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So in the final chapter of the long saga that has been connecting my Raspberry Pi to my Campus’s WiFi network, I needed a way to obtain the IP address of the Pi without using a display or a serial cable.

I’m actually pretty proud of this and I think it’s an elegant solution to a fairly annoying problem. Here’s a video of the system in action:

The program starts with three blinks. After that, the pattern goes as follows:

So

Etc. Four short blinks indicate a 0 and six short blinks indicate a “.”

Once the address is fully read out, three long blinks will occur.

Here’s the code:

You can make it run every time the Pi boots with:

Add the following line:

And your good to go! You can now press the button any time the pi boots to get the IP address without connecting anything!

Parsing Serial Data Sent To Arduino

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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!

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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

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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.

PiPlanter 2 | Adding Youtube Upload Functionality

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In order to keep things moving quickly, I’ve decided to take a shortcut when it comes to uploading timelapse videos to youtube. I’ve decided to basically create a function that passes data to youtube-upload, a command line utility for linux that can upload videos very simply.

Here’s the function:

It should remind you a lot of “TryTweet” from the main version of the PiPlanter.

 

Getting a Raspberry Pi on Worcester Polytechnic Institute (WPI) WiFi (WPA-EAP)

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The following is a very specific guide and like all guides of this nature written by me it is mostly for my benefit so I can come back to it later. It is a modification of this guide written by Campus IT.  If you have any suggestions to improve anything, PLEASE shoot me an email or leave me a comment below.

I will be connecting my Raspberry Pi Model B+ running the latest build of Raspbian using the Edimax EW-7811Un WiFi dongle to this kind of network (From Campus IT):

Specifically, WPI requires 802.1x EAP-TLS certificate based authentication. This is sometimes referred to as WPA Enterprise

Having an internet connection will make doing this much much easier. In fact, if all you need to do is share your laptops WiFi with the Pi over the Ethernet port on your laptop that is quite easy (For WPI people please note that this is a violation of the networks’ acceptable use policy). For windows 8.1:

First, we will have to enable sharing our Wi-Fi through the Ethernet ports of our computer.

Open the Network and Sharing center on your computer. It is found under Control Panel->Network and Internet->Network and Sharing Center.
Next, click on “change adapter settings.”
Right click on your Wi-Fi, and select “Properties.” You will most likely need to be an administrator for this step.
Click on the “Sharing” tab.
Check the “Allow other network users to connect through this computer’s Internet connection” checkbox.
Hit OK to close this window.
Next, we will connect to the raspberry Pi over our Ethernet cable.

Open up cmd. Type “ping raspberrypi.mshome.net” into the command line. Do not use any quotes when you type in this command.
Take note of this IP address. You can connect to the Pi through Putty using that IP address.

If you’re using a fresh install, make sure you set the Pi’s internal time to the proper time using raspi-config. It’s under internationalization options.

You will then need to register the MAC address

Next we need to acquire the proper certificates.

Campus IT has already created a good tutorial for doing this found here. You’ll want two get two certificates seen here:

Move those two documents onto the Pi as well. I’m using

as the location for my certificates for the sake of this tutorial.

From there you’ll have to convert the ‘certificate.p12’ document to a .pem format with OpenSSL. OpenSSL is installed by default in Raspian. Do this with the following command:

Enter the password for the NETWORK when prompted. We now have 3 certificate files. The CA-.pem, certificate.p12 and certificate.pem all located in the /home/pi/certs directory on the pi.

Next we have to disable all the default wifi settings that come with Raspian. Do this by changing your /etc/network/interfaces file to the following:

Doing this stops the Pi from trying to use the wlan0 device at boot and will allow us to use it directly.

Now we must configure wpa_supplicants. It doesn’t really matter where you put the configuration file, but the raspberry pi places it by default here:

Edit the file to look like the following. Note that things you WILL have to change are marked with []’s. Also note that this config places all 3 certs in that directory I’ve mentioned a few times.

I found that in an example configuration of wpa_supplicant.conf specifically notes the need of a .pem file for the client cert, thus the conversion.

We’re pretty much done, all we need to do is add a few steps to the boot process to start the whole process each time the device boots. We can use crontab or /etc/rc.local (thanks Greg Tighe) to accomplish this.

With Crontab:

Add the two lines to the file:

or edit /etc/rc.local to contain:

And reboot your pi! Everything should connect and work.