OK guys, clearly I’m bad at naming things, but at least my titles are descriptive. The “PC based Arduino Sun Harvester Program Interface / Solar Radiation Data Analysis Program Update” is exactly what it sounds like, it’s an update to a PC based program that I put together about one year ago that is able to do two things, interface with the Arduino Sun Harvester Program and also help you figure out how much energy you can get from heliostats, stationary collectors, or dual axis sun trackers.
Over the last few months I have been quietly working on several different additions to the Open Sun Harvesting Project. This is just a quick preview as I still have a lot to do, but everything is rapidly coming together at the same time it seems.
The first addition that will be released in the coming weeks is the Sun Harvester Driver Board V1.0. This driver board is based on the Big Easy Driver by Brian Schmalz, but has been modified in several different ways to integrate more easily into the existing “Sun Harvester” circuitry. For example, two stepper motor drivers are assembled on just the one PCB, and an ethernet port has been added to make it more “plug and play”.
A breakout board has also designed to make it easy to add additional driver boards to the circuit. So if you want to add another machine, all you have to do is run another ethernet cable and two wires for power from the breakout board to the driver board.
Finally, if you are wondering what the silver thing with all the gears on it is, it is a nearly finished heliostat that I have been working on. This design has been in the works for nearly a year now. I’ve obviously tried construction other heliostats in the past, but none of them turned out very well. This was due in large part because I didn’t own adequate tools for the job. Over the last six months or so though I have invested in the equipment required to do it right. Of particular use is the CNC controlled plasma cutter that I added to the shop!
I do eventually want to have a full heliostat available for purchase from this website’s store, but that will still probably be quite a long way off. In particular, I still have to test this design, make jigs so that I can assemble it quickly, and also come up with the cash required to buy all of the parts required to make them in bulk.
Anyway, I still have lots to do, so I guess I had better get back to it!
The above video shows a group of students from Khalifa University, located in UAE, showcasing their very well thought out project consisting of a heliostat array design, collector, and control system. Even on this small scale, it is reported to be able to generate steam.
It was the video’s narrator, Fatima Adly, that originally contacting me asking for clarification on how different parts of the Arduino Sun Tracking / Heliostat Program worked. The same algorithm that calculates the sun’s position and heliostat angles is in fact incorporated into their program. They also added much more to the program such as wireless control via PC and tablet along with a backup tracking system.
I’m not sure what the breakdown of responsibilities were, but Fatima does seem to have done her fair share of the work. For example, there was more than one instance of her contacting me around 4:00am (her timezone) to try and work out one bug or another. When exactly she slept I do not know, but one thing that is clear is that she is a extremely hard worker!
The pdf and code files below were provided by Fatima.
I finally got around to making a video of the CNC machine I built over the winter. I have built a few different CNC machines in the past, but none of them were especially accurate. I took my time with this one though, and it actually turned out really well. Finally! I have a CNC that cuts out circles that actually look like circles!
It probably took about 100 hours to design and build this machine, so obviously I’m going to show it off now that it’s finished! I only have the video for now, but if people show enough interest I might do a full write up on it.
This heliostat was built by Josema of Spain. The machine itself is controlled by the Arduino Sun Harvesting Program featured here on Cerebral Meltdown.
You may have noticed that the mirror is mounted on top of a solar panel. This is because this heliostat also doubles as a sun tracker! Here is a quick video he made of it switching between heliostat and sun tracking mode.
Josema reports that the machine has great tracking accuracy due in large part to the worm gears he is using. These worm gears were originally used to move the power windows in cars. If you are interested in designing / building your own machine, this type of worm gear would be a great starting point.
This next picture shows Josema’s DIY electronics circuit wired together, which appears to be quite similar to the circuit used in the Arduino Sun Harvester Shield. Very Cool!
You can find more pictures of Josema’s heliostat on his blog. (The link should go to the Google translated version.)
You can also find his forum post on this site here.
The Stepper Power Control Boards which allow you to control multiple machines with the Sun Harvester Shield are now in stock! I only have 14 available right now, 8 without screw terminals, and 6 with screw terminals. It’s possible that they will sell out fairly fast since people will need to purchase one for every machine that they want to control. Thus they will most likely buy multiple boards at a time.
I will order and assemble more boards as soon as I’m able though, so hopefully they won’t be out for long when they do sell.
You can find out more about the Stepper Power Control Board without Terminals here,
and more about the Stepper Power Control Board with Terminals here.
As I’ve mentioned before, it is one of my goals to put together a worm gear based heliostat design that can be assembled with basic off the shelf components found at your typical hardware store. Aside from the stepper motors, limit switches, and Stepper Power Control Board (not strictly required), I was able to get everything needed to build this machine at my local Lowe’s store.
Experience has showed me that worm gear based machines are much easier to set up than the linear actuator based machines I have put together in the past. It probably only took me 15 minutes to mount and align this one, and that includes the time it took to get all of the various tools and things together.
The first batch of Sun Harvester Shields have all been sold off. Using the profits from it, I was able to purchase the parts for the shields in larger quantities. Put simply, this has allowed me to lower the price of the boards by $4.00 due to the fact that the cost of electronic components decreases when you buy them in bulk.
I’m also going to try and have the Stepper Power Control Boards available relatively soon. I just need to order more parts and assemble them. They keep selling out before I have a chance to put them in the store.
I’ve heard it mentioned that the Avayan Electronics driver board is no longer available. There are of course many other driver board that can be used with the Sun Harvester shield. One example is the Easy Driver board. If you go to this forum link, I have posted a PDF wiring diagram that will show you how to wire them to the shield. (The link should automatically take you to where it is located, Reply #49)
I finally had the chance to document the Linear Actuator based heliostat that I built. In general, linear actuator based heliostats can be a pain, so I don’t know if you really want to bother building one. I did need to have one around for testing the program though, so I went ahead and built this one.
I hope to have a wormgear based heliostat put together fairly soon. I’ll make sure to document that one too once it’s up and running.
You can find tons more information about this heliostat on the forums here.