In our SBC Project series, we feature unique and interesting single-board computer (SBC) projects from the maker community. If you’d like to share your Raspberry Pi, BeagleBone Black, or other SBC project with thousands of other makers, complete our short form and we’ll get in touch!
In this post, we’ll meet John Whitson from Pensacola, Florida.
What are you working on, John?
I’m automating a small tropical greenhouse, as part of a larger home automation project.
What hardware/software are you using?
Raspberry Pi B+, Arduino UNO and other Atmega328-based AVR, using code and hardware from both AdaFruit and LowPowerLab (especially the Moteino and RFM69HWradio module).
Why did you get involved with this project?
I am building and stocking a small tropical greenhouse, and would like better control of the environment to ensure it’s always at, or near, its best. This greenhouse is an important visual part of our home, and needs better control than I’ve been able to achieve manually. I am trying to add some intelligence, and precision, as well as to collect some data about temperature, soil moisture in different zones, plant condition, air movement, etc. Initial State has a product that seems well suited for my intentions.
What has been your biggest challenge with this project?
I’m in the beginning phases of the project. So far, my biggest challenge has been obtaining components in a timely fashion. We live a distance from a major metropolitan area, and the local Radio Shack stocks more cell phone parts than discrete components (I miss the old Radio Shack).
Do you have pictures of your project you can share with us?
This is a half-size breadboard, and the ATMega328 is under the sticker (which, I might add, is the wrong size, but at least sort-of lines up with the correct pins). In this image, it’s slowly fading up, then down, a red LED attached to what would be Arduino pin 9, using Pulse Width Modulation (PWM). Since I don’t expect this project to really do much PWM, this was mostly just to demonstrate that:
- The circuitry worked
- I hadn’t screwed the chip up to terribly badly
- I could reliably transfer code into an ATMega328 on a board I built (I alternated between the “fade” demo and the “blink” demo)
- As Proof of Concept (POC)
- To make sure I at least vaguely understood the workings of a USB to Serial cable
Note: the 220pF cap wedged between pins 23 and 24 on the breadboard connects (ultimately) to pin 1 of the ATMega328. It serves to momentarily ground out pin 1 when it’s time to transfer code. Also, it’s almost invisible in real life (and certainly so here), but there’s a jumper that connects that pushbutton to pin 1 going the other way, to short it to ground when the button is pushed.
It works. That’s the big deal here, and I’m probably going to transfer this to an Adafruit Perma-Proto as a “reference architecture” going forward, just to remind myself of what it’s supposed to look like. That’s always an important thing, and I need all the help I can get with things like that. When the Reference Board is done, I’ll share it as a picture, and things should make more sense. Who knows? I might even use some pretty little surface mount LEDs, just to make it cool, but for now, I’m in love with that blue LED. It’s just gorgeous.
I might just do blue LEDs for “power on” from now on.
Learn more on John’s blog.
Do you use Initial State for data streaming or visualization?
Not yet, but I’m not collecting data yet. I will be adding temperature/humidity sensors soon.
Any additional comments, notes or resources you want to share with the maker community?
I have found many useful resources on the internet for single-board computer projects. So far, my favorites are (in no particular order):
- InitialState (ideas, data manipulation)
- Amazon (components, single-board computers, technical guides on Kindle)
- Adafruit (components, training, software)
- Element14 (ideas, training)
- RaspberryPi.org (thank you, guys! Brilliant platform single-board computer)
- Instructables.com (ideas galore, software)
- LowPowerLab (components, assembled microcontrollers, communications, code)
- SeedStudio (ideas)
- Sparkfun (components)
- Mouser (components)
All of these sites have been invaluable, as has my local RadioShack manager, George, who is quite enthusiastic, but completely uneducated about these new products which have been showing up in his store. Kudos for RadioShack for getting back to their roots, and to George for jumping in and learning as much as he can.