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An Acquistion of a Company kind I just stumbled upon the following article about Energy Micro and Silicon Labs. http://www.energymicro.com
ews/silicon-labs-to-acquire-energy-micro   Within it there is a link to a letter addressed to its customers. http://www.energymicro.com/company/dear-valued-energy-micro-customer ...
Practical Energy Harvesting I'm now back in my Lab and able to lodge decent posts. Here's a dual purpose Car Port - It keeps the shade off the cars and also generates power. Plenty of power for an EFM32! ...
The last post was very short, just a picture of the layout of my board, becaus I really, really, really wanted to get into my bed. Which I did. I will now describe what I've done the last few days.   Datasheet reading In my second-last post I pointed out some specifics about the LTC3108. After configuring that, I went on to design the schematic for the EFM32. At first I was feeling a bit awkward about using the EFM32 Giant Gecko series for the simple task I was performing, and especially fo ...
gelmi

Energy optimized code (II)

Posted by gelmi Jun 29, 2013
In this post I would like to describe what the code does when the chip is woken up once a minute or when the TEST button is pressed. I will mention only the most important parts of the code. If you would like to investigate it more, you can check source files which are uploaded with this post. The picture below presents the basic dataflow of the code. After the wake up the reset cause is being checked. If the reset was not caused by any of the implemented EM4 wake up methods, in other words  ...
gelmi

Energy optimized code (I)

Posted by gelmi Jun 27, 2013
I finished writing and testing the code for my project. I do not know if you remember, but in one of my previous posts I measured the average current consumption of a simple, cheap CO detector to be around 500 uA (@3,3 V) – that is being consumed by the whole standby and sensing functionality. This is a way over what I can supply from the TEG when harvesting energy from hot water tap. That is why I used Energy Micro STK with EFM32 Giant Gecko on board to create my own CO detector device. B ...
Whow! It was great to see so many Polish developers joining the "Energy Harvesting: Intelligence and Efficiency - In Touch Workshop" in Krakow this Tuesday!   Thanks! Please share your experience here that other Europeans are considering to join the ones to come!   Upcoming seminars: http://www.element14.com/community/docs/DOC-54235?ICID=energy-harvest-group   ...and we have met "Gelmi", one of the road testers! Gelmi, have a successful finish of your road test!   ...
Hi All,   This is just a note to say that I'm still working on this project and that I have some interesting pictures about Energy Harvesting. I have found a few teething problems with Windows that has prevented me from posting blog entries. As soon as I get access to my normal equipment I will be able to post them.   Also, the parts of Greece that I visited had very poor Internet access 50 Euros (about $80) supposedly bought me 7 days of unlimited access. It was more like 6 days ...
Hell yeah! I finished the schematic and layout of the board. Tomorrow I have very little time, so I'll try to update y'all on friday night what the rest of my plans is..... ...
Hello All,   After my previous post, about having worked to get something finished before 12th of June, where it should have been July, I've started designing my schematic and PCB. Somehow, this process always takes more effort than I see upfront. I had to make parts (footprints and schematic symbols) in Eagle for the LTC3108, Wuerth transformer and the EFM32GG940, and of course determine which parts should surround them. I've considered taking a smaller variant of the EnergyMicro controll ...
vsluiter

I #facepalm to myself

Posted by vsluiter Top Member Jun 17, 2013
    D'oh... I thought the challenge ended on the 12th of June, where it was the 12th of JULY. Which gives me a month of time to continue, where I hade been working quite hard to get a working demo on time. D'oh again.   What now? I'll invest some time in trying to design a PCB to finalize this circuit! As I had described before, I would have loved to do that had I had enough time... I don't think I'll have enough time to get the board made in time due to PCB manufacturing and shi ...
As promised I uploaded the video from the tests. Because I do not have a special equipment to test the sensor with the exact ppm value gas concentration, I wondered how to create CO gas in home conditions without risking CO poisoning. I came with this idea. When something organic burns it creates CO2 and H2O (complete combustion), but if there is not enough O2 in the environment (half combustion) the CO instead of CO2 is produced. The simple way to do that is to burn something in a closed jar. T ...
Slipping into Greece Here's just a short post to inform everyone that I've just in arrived Greece after a fantastic week in the UK and Germany. I shall post more details about this soon.   For some reason my last blog post fell of the radar. It was to explain why I did not take my Energy Harvesting To Go Kit abroad.   For me I think it was a good call not to bring my prototype because my bag was rescanned and carefully scrutinized at an Airport security checkpoint where a superviso ...
gelmi

CO sensor

Posted by gelmi Jun 15, 2013
To sense carbon monoxide concentration, I took many sensors into consideration. The one I have chosen for my design is TGS 5042 from Figaro. There are 3 main reasons that this sensor is perfect for my application: This is an electrochemical sensor – it does not need power supply. It is filled with some chemicals which in reaction with carbon monoxide produce current and the sensor works as current source. Plus, other gases and temperature (especially home environment temperature range) h ...
Yes, real eggs were harmed doing this experiment I took last night:   What I forgot to film: Tasting it! Although the part of the yolk wasn't as firm as I hoped it would be, the egg as a whole was very tasty, I must say.   Sequel: This morning I did another experiment, where I didn't let the water get to a full boil; at 95 degrees I turned off the fire, and waited until the yolk would get around 90 degrees Celsius (taking a bit of margin after yesterday evening). The eggs came out f ...
Harvesting: the final frontier... It feels like I've just manouvered my egg-spaceship to a place that had to be explored; after months of travelling through low-power switchmode fields and changing my warp-core throug all low-power modes I finally put it all together; I'm harvesting energy and using that energy to do a complex calculation on the microcontroller.   The pan Here you can see how I prepared my egg pan; on the top I mounted the heatsink and TEG I took from the demo board (mou ...
Calibration - resistance 270 Ohm - 253 = -6% 1k2 Ohm - 1188 = -1% 15kOhm -   15000 =  0% 120kOhm - 114503 = -5%   With 5% resistors, I think this is pretty good; probably the error is distributed between my measurement and the resistor error   Programming the temperature gradient As stated in my previous post, I was modelling the temperature gradient in the egg as a linear model, represented by thermal resistance and thermal capacity. I 'guestimated'  the time c ...
gelmi

Energy sweet spot

Posted by gelmi Jun 3, 2013
I am still developing my project. It is not ready yet, but I would like to share with you two things. The first one is the plot of TEG voltage just after I turn off the hot water tap. This data is when the TEG is under load (STK temperature demo). The board is still operational for over 15 minutes. This is how the device can still harvest and store energy after the water stops to run. The other thing was a little bit unexpected for me. I have noticed this after some time. When hot water runs th ...
On the Road again. Just a short note to say that I'm just about to embark on a visit to Europe. I will be taking my Energy Harvesting Solution to Go kit and associated paraphernalia and am in the midst of finalising my preparations. Being without my lab this visit will limit my activities to research, programming and testing.   I will basically be my own Energy Harvesting: Intelligence and Efficiency - In Touch Workshop.     ...
See the title; I'll be going off-topic. A bit. Why bother (or: how does this relate to the Energy Harvesting Solution)? The reason I'll be looking into the physics of boiling an egg is that for this energy harvesting solution I wanted to make something that would use the computational power of the EFM32. I've had the idea of making something that would monitor the temperature of water for making a good tea. To make a good tea, you need to first boil water, and then let it cool down until the te ...