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Senin, 30 Mei 2016

NASA Spaceship And Mission Control Desk

Spaceship in bedroom
You have to watch this video of a homemade NASA spaceship and Mission Control desk, part of which is controlled by an Arduino.

The above video is featured in the June 26 "Making Fun: Kid’s Room Spacecraft" post on the Make magazine website. The Mission Control desk featured in the above video and Make post was highlighted in a February 19 Make post, "Making Fun: Mission Control Desk," and was explained in this video. If you liked the video and are interested in details of how Jeff built some of the parts, make sure to read the two posts linked above.

After watching that spaceship video, I was both inspired and embarrassed. Inspired by the awesome job Jeff Highsmith did of building the Mission Control desk for his sons, then later building a NASA spaceship thats linked to the Mission Control desk.
Control panel in spaceship

As someone interested in learning about microcontrollers (MCUs) and about building things with MCUs, I was very much inspired by the variety of switches, lights, controls and realistic panels on the amazing desk and spaceship that Jeff built for his sons. As an engineer I was also inspired when he said in the video, "I put in an iPhone dock for future expansion. For now it will just play video from NASA, but in the future I plan to have some homemade satellites to monitor." I dont know if he meant homemade satellites that hang from the ceiling of his sons room, or if he is figuring that in a few years, there will be civilian satellites and he plans to have one or several of those civilian satellites be his. Either way Im sure his expanded system will be cool, and his sons will have a great time with
Mission Control desk
the desk, the spaceship, the satellites and other additions Jeff and the boys make to their private space program. Can you imagine how much those two boys are going to know about electronics and building stuff by the time they reach high school!

Now to the embarrassing aspect of the Highsmith Space Program. Im a bit embarrassed I never made anything half as cool as that for my kids. Im also a bit embarrassed that the Humboldt Microcontrollers Group hasnt come up with a really unique and interesting project that four or more people want to put a bunch of knowledge and skill into that will make people who see it say, "Whoa, thats really awesome!"

There are a couple things that I want to do a little differently as a result of watching Jeff Highsmiths videos and reading his Make magazine posts about the Mission Control desk and the spaceship.
Payload bay remote camera monitor

The first thing to do differently with MCU projects is to think big while paying attention to details. Jeff appears to have had a big picture idea of what he wanted for his sons -- starting with a homework desk that can convert into a NASA Mission Control desk, then extending the space theme to his other sons bedroom with a spaceship. But what makes the desk and spaceship fantastic accomplishments is the close attention to the details. The control panels have complex and extremely realistic looking labels, switches, lights and controls. To make the experience authentic for his kids, Jeff incorporated recordings from NASA and simulations of actual astronaut problems. I realize the only way to tackle a large project is to break it down into small steps, but you have to have a good picture of what the large project will look like, and you have to pay attention to the small steps. When you know the big picture, and youre taking care of details, then commitment and perseverance have to kick in.

Mission status light panel
So, for the Humboldt Laser Harp and the Electronic Light Orchestra, the Humboldt Microcontrollers Group should discuss, agree on and document what the big picture is. How much time and effort do people want to put into that project. Next we should get more specific, more detailed on the finer points of what wed like the Humboldt Laser Harp to look like and to do from both a music and a lighting standpoint.

The second thing to do differently on MCU projects is taking more photos and videos at each stage of a project, planning ahead of time the shots to capture for each project. Jeffs videos have excellent documentation of building the desk and spaceship. I became less embarrassed but no less inspired when I read that Jeff is a full-time videographer. That explains thinking things out enough ahead of time that he captured cool construction sequences while he was building the projects. It would be really good if the Humboldt MCU group could find a videographer or two who are interested in MCUs and electronics and would like to participate in the groups activities. They would know how to capture the story of a project, and theyd be able to put together a cohesive and impressive video.
Ardunio used to control instrument panel

I think Ill keep a link to Jeffs spaceship video handy and watch that regularly to keep me inspired and to remind me of how rewarding completion of a big, complex project can be.

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Minggu, 22 Mei 2016

Ultra Low Power Microcontroller With A Supercapacitor

This post is a follow-up to this blogs FRAM (ferroelectric random-access memory) post in June, and takes a look at a recently-introduced Texas Instruments (TI) FRAM LaunchPad development platform, as well as how to use FRAM effectively in a particular use case.
TI MSP-EXP430FR5969

First the FRAM development platform. It appears from a post on 43oh.com that the MSP430 ULP (ultra low power) FRAM board, MSP-EXP430FR5969, was soft-launched in February 2014, then rolled out with more fanfare and distributor partners in June 2014, per the Australian post, "element14 offers ultra-low power with Texas Instruments LaunchPad dev kit," and a number of other similar new product posts. The Australian post above says,
"Embedded FRAM, a non-volatile memory known for high endurance and high speed write access, together with ultra low power makes the MSP430 development platform suited for a wide variety of applications ranging from metering, wearable electronics, consumer electronics and the Internet of Things (IoT) to industrial and remote sensors, home automation and energy harvesting. The new development kit includes TIs new EnergyTrace++ technology, the worlds first debug system that enables developers to analyse power consumption down to 5nA resolution in real-time for each peripheral...Key features include MSP430 ULP FRAM technology-based 16-bit MSP430FR5969 MCU; 64KB FRAM/ 2KB SRAM; 16-Bit RISC architecture up to 8-MHz FRAM access/ 16MHz system clock speed; 5x Timer Blocks; Analogue: 16Ch 12-Bit differential ADC, 16Ch Comparator; Digital: AES256, CRC, DMA, HW MPY32; 20 pin LaunchPad standard leveraging the BoosterPack ecosystem. Various components including on-board eZ-FET emulation for programming, debugging and energy measurements have been provided in the evaluation kit for a fast start; on-board buttons and LEDs on the board enable quick integration of a simple user interface in addition to a SuperCap allowing standalone applications without an external power supply."
MSP430FR5969 LaunchPad Power Domain Block Diagram
The part that especially interests me is the SuperCap that enables a minimal level of operation without an external power supply (and without a battery?). Enabling MCUs to operate without external power sources was the topic of an earlier post on this blog, "Microcontrollers: Batteries Not Included. Or Needed." That post discussed getting the MCUs power from small energy harvesting devices. It would be nice if a supercapacitor turns out to be another no-batteries-needed option for MCUs. The boards Users Guide shows the power domain block diagram to the left and says, "The board is designed to support five different power scenarios. The board can be powered by eZ-FET or JTAG debugger, external power, BoosterPack power, or standalone super cap power." A bit of online research is needed, it appears, for me to totally understand just how much the MSP-EXP430FR5969 board can do using just the 100 mF capacitor and no external power. If Google and I cant figure that out, Ill check with Ed Smith to get my answer!

If youre interested in the MSP430FR5969 microcontroller (MCU) that powers the above development platform, consider reading the Electronics Weekly article, "Exploring FRAM microcontroller-based design – Texas Instruments." The graphic at the right from that article shows how flexible the memory configurations are in that MCU. Here are a few more resources to help you learn more about the MCU and its platform:
  1. MSP430FRxx MCU overview page on TIs site.
  2. MSP-EXP430FR5969 LaunchPad Evaluation Kit page on TIs site.
  3. Overview of MSP430 Ultra-Low-Power MCUs PDF on TIs site.
  4. MSP-EXP430FR5969 LaunchPad Development Kit Users Guide PDF on TIs site.
  5. 6-part video tutorial on YouTube for the MSP-EXP430FR5969.
If you want to buy the MSP-EXP430FR5969 kit, Id suggest you consider either direct from TI ($24.00) or from Newark ($24.05). Octopart gives a good look at the price spread and availability of the kit, with costs ranging from TIs $24 up to more than $39 from Arrow. The 43oh post above shows one way manufacturers entice hardware developers to buy newly released components. For $5 extra ($29 for the kit instead of $24), when you ordered the MSP-EXP430FR5969 kit from TI when it first came out, you got both the kit and a "LS013B4DN04
SHARP Memory LCD display...1.35?...96×96 pixels wide...booster PCB has touch capability, with touch strips on either side of the LCD" which retailed for $18. I dont know if $5 for that LCD is a better deal than the small LCD Ed Smith had at the Humboldt Microcontrollers Group meeting last week, but the touch strips would have made it an interesting component with which to experiment. Element14 also has a road kit for the board which includes the same LCD.

The other part of this post was going to be on an ideal use case for the MSP430FR5969 MCUs FRAM. However, I wrote more about the TI development kit than I planned on, and Im being mindful of feedback I got that said (at least some of) my posts were too long. So for people interested in reading about that use case right away, heres a link to the article about the FRAM-MCU application I mentioned at the start of this post. Ill discuss that use case in tomorrows post, and maybe have a couple other examples of good applications for an MCU that doesnt pull much amperage and has FRAM. If you read the FRAM-MCU application article, send me your comments and questions regarding that article -- arcatabob (at) gmail {dott}com. Thanks!

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Selasa, 12 April 2016

Democratize Electronics From Idea To Circuit In Minutes

Squink is a recently launched Kickstarter project which is described as "the personal electronic circuit factory."

It seems like Squink could be of high interest to Humboldt people who frequently prototype new electronics designs, especially ones involving microcontrollers (MCUs). I personally wouldnt need a Squink of my own, but Id love to have access to one. If this Kickstarter campaign hits its funding target of $100,000, every makerspace and hackerspace is going to want a Squink. However, the project appears to be off to a slow start, so I hope the funding pace picks up over the next week or two.

According to the BotFactory website,
"Using inkjet technology, Squink prints conductive ink on a surface to create the traces of the circuit. You can print GERBER RS-274X files or upload PNG, JPG or BMP files...Squink uses the soldermask file generated by your CAD tool to place dots of conductive glue in every connection point where a part is to be connected...Aimed at assembling SMD based circuits, Squink uses vacuum to pick components from a tray. Then it aligns them using computer vision, rotates them according to the "Centroid and Rotation" file created in your CAD tool and places them accurately."
Squink is a simplified printed circuit board (PCB) fab and assembly prototyping tool. However, the TechCrunch post says that the Squink founders arent trying to replace the PCB batch fab companies like OSH Park, or the straightforward PCB fab companies.
"They don’t want Squink to replace the current process of sending projects to manufacturers to build but want it to be a tool for people to test out their ideas immediately, without having to create a delay in the creative process. “We really want to be a stepping stone — try it out really quickly and once you’re ready, then you crank out about 100 boards from a manufacturer..."
The BotFactory blog gives a little more background on the genesis of the Squink concept.
"We were both attending a challenging class on Bio-electronics...you had one semester to design, assemble, and test a basic EEG system (also called a brainwave reader; our version was capable of measuring attention and winking). While the design of the EEG probes on paper and then on a CAD program took a big part of the semester, what was later revealed as the most critical part was the circuit fabrication itself. Out of the 8 teams, only 1 managed to finish on time for the end of the semester. The reason was simply frustrating: it took PCB manufacturers around 7 to 10 days to fabricate and ship all the boards. If you had made even a single mistake in your design, you had to send your design for fabrication again, and you were sure to miss the deadline."
Although the implementation of the concept may seem a bit simplistic to PCB designers who are used to complicated circuits on multi-layer boards with very narrow traces, I expect people using the Squink and similar personal electronic circuit factories to come up with novel and interesting applications over the next few years. I have no doubt that enterprising middle school students who get their hands on a Squink will make money printing off custom circuits for their friends and neighbors. And those same middle school students will later develop a new printing technique, or a new electronic circuit substrate, or some other personal electronic circuit factory concept that no college student or electrical engineer has yet thought of...

What MCU circuit would you print tonight if you had a Squink to play with?

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Jumat, 08 April 2016

Airlifts Geysers and AquaZen

I want to begin by saying I am not an expert with airlift design.  My results  differ from others who have spent more time experimenting with airlift technology.

I like airlifts because they are less expensive to operate and can be built for only a few dollars.   Airlifts aerate the water and are able to pass objects such as way ward fish without clogging.  They have no moving parts; instead they rely on an external air pump which would in most aquaculture systems already be present.

In the video below I experimented with three types the pumps.  A simple Airlift, a Geyser Pump and an AquaZen Airlift.  This video documents the results.

This video shows me running five different airlift configurations.
All of the designs performed very close to each other.
Some factors that may be influencing the differences are the diameter of the pipes and the number of turns.
Each test was performed with a 200 lpm EcoPlus 7 air pump running at 93W.
The vertical pipe was submerged 24-1/2" and the rise was 13-1/2" +/- 1"


Test #1 Simple Airlift with Separator - 5 gal/62 seconds
Test #2 Simple Airlift w/o Separator - 5 gal/58 seconds
Test #3 Geyser with Separator - 5 gal/74 seconds
Test #4 Geyser w/o Separator - 5 gal/50 seconds
Test #5 AquaZen - 5gal/58 seconds

In each case the separator appears to actually reduce the performance. Sorry I did not run the Aquazen test without the separator.  I believe the loss of performance is due to my design and I will try to make this part more efficient.

The Geyser and Simple Airlift performed as well or better than the AquaZen. But there are many factors that may have been overlooked. As far as I know the check valve was installed correctly and there were no significant leaks. The submersion and rise were kept within a 1" tolerance and the barrel was filled to the top each time.

I hope others will take the time to build and test these, and other airlift pumps. More data might help. It may also be that they each operates best at different lifts. I still have so much to learn
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Rabu, 30 Maret 2016

Low Energy System Design



...Download this Sketchup Model..

This system has two radial filters and a media bed to keep the deep water culture raft very clean, An airlift pump keeps the water moving via an air compressor; no mechanical water pumps are required

Water levels in all the tanks are the same. By not raising the water from a sump tank only a small amount of energy is required to move the water laterally.

If this entire system were buried flush with the ground the thermal mass of the earth would help regulate the temperature very well during both summer and winter 


Airlifts  provides both water circulation and aeration. I believe airlift pumps can be more efficient than an external pump.  (Ive never understood why submersibles are always less efficient, but the specs tend to indicate this).
Airlifts can be calculated.
This article Performance Study of an Airlift Pump with Bent Riser Tube presents an interesting conclusion is that bends in the riser pipe do not effect the performace of an airlift pump.
OPTIMIZATION OF A BACKYARD AQUAPONIC FOOD PRODUCTION SYSTEM
is a very good paper about aquaponics and it would be a very good source for information about airlift pumps but a critical table is missing.  Id still recommend reading it for everything else it presents.



I found this calculator for airlift pumps.  It is spot on against the real life experiments Ive conducted.

From my own experiments without math; I believe an airlift will provide enough water circulation.  That is also what Keith Tatjana demonstrates in his paper in which he assumes a circulation rate of one fish tank volume twice per hour.
I think air blowers are more reliable than water pumps, and less expensive.  Blowers do not provide the pressure like a compressor so this is a limiting factor when using a blower, but if at all possible use an air blower because air compressors like the Hydrofarm 70 and 110 lpm units tend to vibrate themselves to death.
I have not done any experimentation with how much ambient air temperature will affect the water temperature, but logically this would occur whether it be from an air stone or an airlift pump.
Other papers Ive found are
Performance Characteristics of Airlift Pumps withVortex Induced by Tangential Fluid Injection
Explore the Potential of Air-Lift Pumps and Multiphase  
Explore the potential of air-lift pumps 

A geyser pump, an improved airlift pump
The Geyser Pump improved the amount of water pumped from 40 gpm to 60 gpm in one experiment I conducted.  

This Video shows the Geyser Pump I built. http://youtu.be/ztHBHULkHNQ


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