Wednesday, April 29, 2009

Stand Up!


Well I've been in Texas for a few days and its been pretty nice. I've had time to lay the electronics out and work on things as well as build a decent prototype/test stand. The new rod I got in Santa Cruz feels totally beefy and there is hardly any flex. The stand did feel a little vulnerable though because the friction of the bicycle seat post clamp isn't really up to the wind torque that can be exerted from the forward position of the mirror assembly. I've got some heavy boards making a 6'x8' cross and the center of gravity is pretty close to the middle, while the mount is to the rear. Since it's been really windy here, I used some rope to tie the front down so it won't move. I'm going to leave it outside for a while just to observe how it handles the winds. I've got to say, I like the way it looks. It's probably just a parent's bias though. Someone else came up, looked at it, and said "I give you an A for engineering, and a C for asthetics." Ouch.
One thought about the stand is that a forward mount with some sort of provision for yaw adjustment (i.e. north/south alignment) would help solve much of the stress issues. Parking in a horizontal position also greatly reduces surface area for wind resistance and reduces loads. The final model needs to go into Park mode under high winds, probably by sensing excessive vibration rather that wind directly.

I spent all day yesterday working on the i2c bus and ds1307 clock module. I had missed a solder point on the chip socket leading to about an hour of fiddling with the software before finding the missed pin while double checking the circuit.

A significant portion of the previous day was spent building headers for the i2c cable (cat 5), and in the process of hooking everything up to get both boards and the clock all talking over the i2c bus, I realized that I had to add a reset line for the mirror/motor control module so it would properly sync up after the ui/command module booted.

The Arduino IDE has been a headache lately, I learned the hard way that multi-line parameter lists for function definitions completely throw the IDE line count off and compile errors become very hard to line up with the causative line! I'll try the new rev and see what the guys on the forum have to say about it.
My FSM for the command module needs a lot of work yet, not to mention the rest of the code issues. Slowly though it is coming together. Today I finished a routine for setting the date/time for the clock which gets triggered on boot up if the clock has lost power too, which mine does since I lost the darn battery!
Have I mentioned that this stuff takes a lot of time? No, really -- lots of time, everyday. Four months of work now. So much for that original two month schedule! Still I feel like my basic assumptions about the design are all sound, and production issues should be minimal. What is becoming more and more clear is how hard it is going to be to make people understand the significant differences between heliostat arrays and parabolic type reflectors, and the advantage of heliostats. The heliostat is just an enabling device for the target device, and as of yet I have no official target device built, so it just looks to some like I'm shooting into space. Multiple targets have to be built to demonstrate the full concept.

Saturday, April 25, 2009

Texas Time

Well, I made the journey without too much drama. It was a little nerve wracking. The van wasn't running good, funds were tight, and certain legalities were put aside. I had a little moment in El Paso where I looked down for some peanuts to snack on, while waiting to leave a parking lot, and accidently rolled into the car in front of me! Fortunately there was no damage, and we both happily drove off, though I might have been a little happier than the other person was! What a close call!
I'm writing this from the cabin I helped build last fall. It hasn't been finished out inside yet, but it looks like I'm going to call this home for at least a little while now. Home is becoming an increasingly abstract concept for me after 6 years of drifting about. Though I rolled after 1am last night, I did some basic unpacking today and setup a little corner to stay in upstairs. I spent a couple hours sorting out all the little electronics that got completely jumbled up during the trip. Now all the LM74xx chips are in order, along with the CM4xxx chips, transistors, resistors, capacitors, LEDs, etc.
I looked around and found a nice 4x6 board and a 2x6 that will make an excellent stand for the prototype unit.....

Monday, April 20, 2009

Command table strings to EEPROM

Saturday I used some Naval jelly on the new rod and then gave it a nice coat of flat black paint.
I went to the temple last night in Santa Cruz and had a great time as usual. Nothing over the weekend for the email inbox. Observing Ekadasi today, energy is way down. I can really feel the stress of the last week. I'm taking some fruits and nuts to make sure I don't freak out and throw-up like last time!
Added DS1307 code to HelioCommand3 as well as introduced EEPROM routinesBegan to work on command/event loop details FSM details need definition...Worked on little sketch to write EEPROM for command module: frees up memory for other stuff by reducing cmd_tbl size and getting other strings as needed from EEPROM rather than keep them in SRAM. This also has the added benefit of architecting the software for international versions (by isolating all the strings in EEPROM separate from program ROM).
Arghh, I bought a lithium watch battery for the DS1307 but lost it before I even used it. Guess I'll make the prototype supply batter voltage from Vcc. That way I'll make a good UI for setting the clock :)

Friday, April 17, 2009

SC gives me the rod!

It was a hard day. I was really sore from tree clearing the last two days. First thing Wednesday morning I helped as everyone pitched in to fell some trees that were already on their way down. We completely limbed the first tree by hand because the chainsaw was out of order. It turned out the trees weren't too dangerous as it took quite a bit of work for us to get them separated from the other trees so they would fall. I had to pull one 60' acacia tree out with my van since it didn't fall when we cut it. Two days of almost non-stop slashing and dragging and piling. At least it probably helped the community feel better about me being here, even though I haven't taken care of any of my own needs, which means I won't have the means to stay.
Finally made it to town today though and sent out some emails. I got really sad because I haven't had any luck getting connected to support myself better. I guess I have to go to Texas. Heliostat wise it was a decent day, I tried a few metal shops on the west side of SC and found a piece of steel rod the right size (1.0625") for the support stand - $10, not bad. It's probably a little over 2' long. The guy that sold it to me weighed it at 7.5 lb before deciding the price. He also touched the rod to a grindstone just to be sure it was steel. Jaya Gurudeva! This was a good move (getting the rod) because I'll probably be a lot harder pressed to find this stuff out on the farm in Texas!
I sanded the frame down and sprayed it with some gray primer and now the old graphics on the bike frame are gone and it is starting to look like it might have some other purpose!
I also spent a little time going through the i2c h-bridge mirror motor module code (got it to compile but that was it)

Monday, April 13, 2009

OMG

I just got the heliostat mirror module to compile using libraries I created for the the motor control. Sweet. Hopefully the debug will be painless from the conversion.
It's been hard to concentrate in this environment, but it is always favorable as long as I can remember my dear Sri Sri Guru-Gauranga.
My cousin hooked me up with some nearby devotees of Srila Narayana Goswami Maharaja and I met them Friday and heard Uma didi speak. Saturday Radhanatha das gave me a ride to Berkeley and we spent the afternoon doing Hari Nama Sankirtan with about 20 devotees and Uma didi came as well. Sunday night I went again and listened to Hari Katha again.
I tried to do some networking, but it doesn't seem yet like I found any connections for here.
Texas is calling...
...but it's frustrating because its going to be so hard to get there and such a diversion for the heliostat project. I'll end up out in the middle of nowhere at Sadananda's farm, but I'll get to see Srila Gurudeva in May. The big question is what next after that.

Friday, April 10, 2009

Homeless Again

Wow, this morning as I got the batteries I had ordered (to run the motors at 24v), I was told that I have to move out. Not quite thrown out on my ass, but almost - one week notice. The way my cousin's husband is acting, I might resort to leaving sooner -- if I can figure out where to go to. Let's see: bank account? $20, wallet $38. It costs $6 just to cross the Golden Gate Bridge. I might have enough gas to get back to Santa Cruz, but what then? I spent all my money on heliostat parts so my car insurance is expired, and I can't get a sticker for my license plate, although I paid the DMV, and my drivers license even expired a couple months ago.
Taking on this heliostat project for me is like a Hail Mary pass in football - if it doesn't work, I've already lost anyway.
I've heard that entrepreneurs have a knack for underestimating the difficulty of doing things. That way they can fool themselves into trying something that no one else wants to do or has already done. That must make me qualified, if not yet successful.

Tuesday, April 7, 2009

The Idea

Hardly anyone knows what a heliostat is. In simple language a heliostat moves a mirror so that the suns reflection off the mirror is stationary while the sun tracks across the sky. Heliostats have been around for a long time and most have been impractical and complex designs. Mechanical and opto-electrical controllers are expensive and lack flexibility. What's needed is a simple to use cheap heliostat run by simple microcontrollers.
Check it out, there's only two web pages out there right now where you can possible by a heliostat. One company wants $2,000 the other $1,500 to get started with a 1sq meter unit. That's hardly going to create an energy revolution. What if one could be sold for half of that? Maybe $750 or even less. This would come out to $0.30/watt of raw energy capacity, compared to more than 20x that for PV.
Are you ready for an energy revolution?
The vision:
Affordable heliostat modules that wirelessly network and communicate with specially designed target appliances which request tracking services from the heliostat modules and distribute the solar power in the most efficient manner.
Example: 5 heliostats, a solar oven, water heater, window, sterling engine/generator
Heliostats target the stationary sterling engine (which uses a fresnel concentrator) providing electricity, occassionally one or two units will switch to the water heater to keep the temperature within the desired range. Someone enters the living room and flips a switch to "turn on the light" which detects that a heliostat is available which is redirected to the room's window bringing both light and warmth into the room. The person leaves the room, but forgets to turn off the switch, the switch eventually detects that the room is getting too warm, and automatically retargets the heliostat back to the sterling engine where it contributes electricity to the grid or a storage system. Now the person enters the kitchen and starts to make a pizza. The solar oven located on the north wall opens its shutters and three heliostats target the oven. Electronics in the oven redirect the heliostats and use shutters to control the temperature as desired. The pizza is half-way cooked when a cloud blocks the sun, and the oven automatically switches to electric or gas backup operation.
This is distributed on demand solar power at it's best.
I could go on and on about the benefits of heliostats over the alternatives. Simple manufacturing, no dependence on precious metals, efficiency....

Birth of an Idea

It was during Christmas of 2008, and I was living in Santa Cruz in what is known as the Apple Orchard Community. I had about $40 to my name, no job, no insurance, and the license on my van was about to expire. I was sleeping in my van, in freezing weather, with no heat, and an outdoor bathroom. Everyone had left to be with relatives, so I was alone. I had a lot to think about. I spent most of last year living in an Ashram in Houston, but felt compelled to come back to California after some disheartening experiences in Texas. I am a Krsna devotee, commonly known as a Hare Krsna, though not associated with ISKON. Even without the headshaving and sheet wearing, it's not a popular thing being a devotee. Few people understand, and I am used to being subject to contemptuous attitudes. Anyway I bring up all this just to help you understand that I have surrendered my life to my guru (Srila Narayana Maharaja, www.purebhakti.com) and although I am a pathetic fallen soul I am trying to serve The Lord as best I can. In this mood I was reflecting on the fact that I was in California with friends, rather than my guru's ashram in Texas. Though I could not see how, I prayed that I could still serve Krsna.
I found a spot where I could get WiFi from one of the neighbors. The Apple Orchard sits on 8 acres, and I never even figured out which of the neighbors on the other side of the woods had the signal, but I was just on the edge of the reception area. Nevertheless it was phenomenal that I could surf the internet and do research without going to town. I pulled up a picture of my father on my computer and just sat back and looked at him for a while, he died in 1984, and it felt nice to spend a little time remembering him and his presence in my life.
When I was in my 20's I spent a Christmas broke and alone, eating Top-Ramen. I ended up writing an incredibly upbeat song that I saw as the present that was given to me at that time. This time it wasn't a song, it was The Idea.
The Idea had to: have the ablity to change the way people live (for the better); be low-tech enough that not only could I develop it, but people in third world countries would be able to build it; be affordable; and be environmentally friendly.
My father invented a tool used to survey oil well holes. His tool used gyroscopes, accellerometers and magnetometers to very accurately determine the hole position. Thanks to things like iPhones and various game devices, digital accelerometers are pretty ubiquitous these days. Accellerometers don't just measure acceleration, they can measure tilt with respect to gravity. How could an accelerometer be used for The Idea? Bingo!

Background

This experiment has been going on for most of my life now. I was in high school during the OPEC oil embargo and energy crisis of the 70's. I was also a debater, and the last year I debated, the subject was energy policy. I studied the subject fastidiously. I went to a summer debate camp at Baylor University and spent 20 hours a day studying for two weeks. I filled cases with index cards sorted by subject and position. I learned that there was always someone saying something about any given subject. Quotes are irrelevant if the sources are not bona-fide. Somewhere between the doomsday people and the naysayers lies the truth. New technologies will not allow us to continue our petroleum addiction forever.
The Experiment has taken various forms, some recognizable, some not. Back in the 80's I tried making a solar powered refrigerator, but didn't know how to make a good enough heat transfer, or have enough heat. A few years ago I got excited about ethanol and did extensive research on it. I realized that the VOC emmissions from large scale production were a serious (expensive) issue, and then the price of corn shot up and people in other countries began to go hungry because corn was going into our tanks, and everyone knew this wasn't a good answer to the energy question.
A couple years ago I was also living in a mountain community that had thoughts of going solar, so I researched it, and I decided concentrated solar power (CSP) held an advantage over photo-voltaics (PV). This was too radical for the community so nothing happened.
Last year a friend of mine scored a new 2hp DC motor while dumpster diving, and it got me to thinking. The motor was for a treadmill. You can always go on craigslist and find a treadmill for free. What if I could make a simple electric vehicle using treadmill motors? Exploring this idea led me to recumbent trike designs, and I wanted to come up with something that would utilize old bike frames. While investigating motor drivers, I came across a website (www.robokitsworld.com) that really sparked my imagination.
Several years ago I toyed with building a robot, and also built an interface card for the PC, but I didn't get too far due to a lack of robot mechanicals which were much harder to find than they are now. When I saw the little microcontroller boards with motor drivers, and digital and analog I/O, I was excited. I knew these little boards could make an idea come to life, but what idea?

Monday, April 6, 2009

Jaya Sri Ekadasi

Not many Americans (North or South) are familiar with the Hindu practice of Ekasi. It is marked by a religious observance which occurs on the 11'th night of each waxing and waning lunar cycle.There are many reasons given for Ekadasi, for those with little faith in Krsna, there are materialistic explanations dealing with the effects of the moon's gravity on water. The only significant explanation from a devotional perspective is that Ekadasi is a direct manifestation of Krsna's mercy and it pleases him when we honor Ekadasi, which means at a minimum fasting from all grains, or ideally completely fasting from even water.
Yesterday I decided to observe Ekadasi by fasting from all food and only taking a little bit of water. It seemed like an OK thing, and I felt pretty good most of the day...
I woke up this morning, and even before sitting up I began crying. I just felt completely empty and unfullfilled. Ahh, the thrilling life of renunciation. The morning after Ekadasi is always a bit intense emotionally, so I was observing and rolling with it. After my prayers I went down to prepare some Krsna Prassadam and break the fast. Before I could even get my oatmeal cooking, I threw up. Barfed. Ughh. There wasn't even anything in my stomack to throw up! Ughh, again. Yellow bile. Shaky legs, low blood sugar, general weakness. If I was in a video game my life energy low warning indicator would be flashing in the upper right corner while motor skills deteriorate rapidly.
Ekadasi has rules regarding when the fast has to be broken: not before a certain time, and not after either.
Furtive glances at clock... try to eat oatmeal... ughh, throw up again, and again, and again, and again. Whooee, this is serious.
I see S outside and he makes a comment (sarcastic, as usual) so I tell him what's going on (he's heard me urping). I told him if he didn't see me in a few hours to check up on me. He replies: "there is a hospital in Corte Madera that takes walk-ins. You can take myself there if you need to." Hmmm, now this is getting clearer. I don't have any psychic skills, but I sure can feel it when someone is having unhealthy thoughts about me. S totally worked himself into a negative vortex of huricane strength because he resented the fact that I spent the day Sunday observing my spirtual practice instead of working all day in the yard like him. Too weak to work Monday because of it? Double the hate.
V said that contact with the devotees quickly gives people liberation or sends them to Hell. The purport of that statement would be that those who are ineligible to receive the mercy of Krsna tend to also be inimical to the point of creating offenses to Krsna and the Holy Name, which quickly robs them of all intelligence causing them to run into the jaws of death, which are no more than gates leading to Hell for such offenders.
This is another reason why it is good for advanced devotees to move about and not stay in contact with materially minded people: because they have compassion for all the fallen souls, and knowing them to be offensive by nature, the pure devotees limit the opportunity for offenses while still sharing sadhu sanga.