2 packages from SainSmart have now arrived. I am hoping to do an unboxing video soon.
The mystery bags from SainSmart that I mentioned in my previous post arrived and we tried doing an unboxing video. I never do this kind of thing and having the kids involved really made it unpredictable and awkward. I wouldn’t blame anyone for skipping it and getting to the rest of the post.
The items for all three “bags” were all together in two packages, so there is no way to distinguish what was in each one. Most things were in anti-static bags which made it difficult to show them on camera, so here is the details of what we found.
This device measures numerous aspects of air quality and I can’t claim to understand even half of it. The page lists three different models and I haven’t yet figured out which one this is or what all the readings are. I can say tell that low numbers are good and I am not surprised by the results where we live.
One thing that is curious is how it reacted running of a USB battery pack. I used a battery so I could get a good picture away from outlets. My battery pack has a button that doesn’t really turn it on and off, but it usually just seems to turn the level indicator lights on and off. In this case when I hit the button, this device kept the screen on, but the values went a bit wild:
One of these days I will look into why this happens, but I don’t see it as an issue with the device.
Another thing that is curious about this item is that I am not sure why it was even in there since it was included in the hints on the premium bag and mine were all the advanced bag. There aren’t any other items specific enough to say what happened. Also, I have no idea what I would use it for so let me know if you have any ideas or would like it. If I were to get something from the premium bag instead, I would have rather an oscilloscope.
This is one of the items I did hope to get since my portable soldering iron is pretty old and basic. In this case, I got three of them (one older version with a single tip and two of the 2017 updated versions with two tips). One of them will become my new portable setup, though I might need a different stand to fit this one. I believe I know someone who will want one of them, so that just leaves one extra to figure out.
The temperature reading seems a bit squirrelly until it gets up to temp, but it is programmable, so maybe that can be fixed at some point. It does get hot pretty quick though not as fast as my solder station.
I have wanted to build an LED cube for a while. I probably would have build a smaller one from basic components at some point, but now I don’t have to. This one plays music, but I am not likely to use that feature. They also sell an acrylic case and a building template to help with construction. I will probably 3D print a grid to help with building, but the case might be nice unless I come up with a way to build one myself.
A really cool one to build would be the AuraCube, but that is just a bit more expensive.
Each of these two kits comes with a 5 meter spool of waterproof LEDs, a power supply, a controller and a remote to change the colors. These were not hinted so they were a complete surprise, but I know I can put these to use somewhere.
I have done a number of LED strip projects before, but I haven’t made the jump to RGB yet. The one thing that has held me back has been picking out a controller that I like. This will give me something to start with and I can figure out what I like and don’t like.
This is one item that was hinted at that I didn’t really care was included. Arduino boards are always useful for some project or another but it is hard to find a project that is worthy of this hardware. I really like the idea of building a pinball machine, but I don’t know if I am ready for a project of that scope right now.
Of all the items hinted at, the screens seemed like the most useful. I would have liked the larger 8 inch screen, but I am sure I can come up with a use for a small touch capable version as well. Now I just need to get some newer model Pis finally.
This one was also hinted at, but I hoped to get something more useful instead. The only purpose I see here is to change the shell from black to blue. Not only do I prefer the black, but I don’t think I care enough about the color that I would buy a different shell.
This tool will indicate if AC voltage is present without contact so there is no risk of causing a short or getting shocked. I have very nearly bought one of these since I seem to come up with a use for it every couple months or so.
I just built two nicer versions of these (read about that here) so I am not sure what I will do with these yet. I may use them as gifts for friends to use for soldering practice.
Pretty standard screen for arduino project. I have several around, but not all of them have I2C backpacks attached.
Also in the box was a Raspberry Pi camera. I mentioned it in the video, but I forgot at the time that I specifically ordered that and it was not part of the mystery bags.
One really strange thing was the oscilloscope probe that was included. The only oscilloscope option was in the premium bag and I don’t see a way to get just the probe. I think these ended up in there by accident.
Overall, the items I got total $505 in retail value. Most of them will be useful or fun.
2 packages from SainSmart have now arrived. I am hoping to do an unboxing video soon.
Last year I ordered a couple of these 3D LED Christmas tree kits from SainSmart at the same time I ordered one of their Fukubukuro mystery bags. There are a variety of LED Christmas trees around ranging from this cheap version on Amazon up to a limited edition one offered by Particle that is web connected. Some of the really basic ones have standard single color LEDs which does not sound all that interesting.
This version has 37 “7 color” LEDs which individually fade between 7 colors: red, green, blue, yellow, something I will call teal, purple and white. Each board has 18 LEDs divided into groups of six that are driven by 3 basic RC oscillators to make them blink. The capacitor and resistor values for the oscillator are pretty flexible and will change the flash rate. Higher values will increase the frequency, lower ones will decrease it. Small variations in individual components will make each section blink differently and the oscillators on each panel are chained such that they will be out of phase with each other.
I tracked down the instructions just to make sure I got the resistors in the right spots. This took a minute because something seems to be a bit broken about the search functionality on the SainSmart learn site. I won’t detail every step because it has already been covered over on Hackaday. It is a slightly different revision, but the same basic process.
The printing on the boards makes it pretty clear how to assemble besides which resistors go where. Once I verified how to do the resistors, I worked my way through populating one board. I recommend doing resistors first even though I forgot this at first. If you put in taller components first, the resistors like to slide out of the board. The LEDs have a flat section in the leads so there is no concern about leaving a consistent amount left to allow them to bend over.
With one board finished, I applied some power to the pads to ensure that everything worked. It is much easier to make fixes before the two boards are assembled.
I did have one set of 6 LEDs on one board that didn’t work initially for some reason. I checked for shorts and the resistor and capacitor for that section, but nothing jumped out. I removed the transistor and tried applying voltage directly to that section, but it still wouldn’t light. I decided to check each LED individually. I removed one and it tested out fine. I checked the remaining 5 again before continuing and they also worked. I reinstalled the LED and everything now works. I still don’t know what the problem is, but I am glad it is working.
The lower board is setup so you can power it with a mini USB plug or the included battery pack. I set the battery packs aside for now since I expect I will have them near usb ports or on outlet for now.
When I went to put the upper boards together, I discovered a mistake. I had gotten carried away and installed the top LED even though it spans across the slot where the other board needs to slide it. It only took a minute to remove one side so I could put them together and then resolder. I also found one other minor problem–a couple of the capacitors would like to occupy the same space. I recommend leaving some room to bend them down flat even though the printing on the board might lead you to solder them close like I did initially. I saw a picture of one board somewhere that is printed to indicate laying the capacitors down. The transistors did brush past each other a bit, but it is not really an issue.
With the tree assembled and fully functional, it was time to put it in the acrylic case. Peeling the protective films off of these sorts of pieces is always a test of patience. Once that was finally complete, I set to mount the tree on the bottom section. I found that the standoffs have to be put in so the nuts are on top of the circuit board and the screws are through the acrylic plate. If they are the other way around it just won’t fit together.
Assembling the case is just what I expected after building similar cases before. Each corner takes a bolt with a nut to hold it together. The nut needs to be slid into the slot (carefully so it doesn’t fall in) and then tighten the bolt into it. I do have two issues with the case.
First, the front and back panels are identical, but this puts the hole just a little too high and not wide enough for the supplied cord. A different cable might almost fit but the hole should be at least a few millimeters lower, so I broke out the Dremel to fix it. Using the battery pack would work just fine. Secondly, the case is not quite large enough for the bottom lights to fit without being adjusted so they don’t stand straight out. Everything still functions, but I would really like it if all the LEDs could line up perfectly.
Despite the small issues, I am happy with the results. I brought one with me to work and left one at home. Everyone loves the look of it and I have a coworker that ordered one of his own. If you would like to get your own, you can get one from SainSmart. They also have one now that is taller and plays music.
Fukubukuro (lucky bag) is a tradition among Japanese merchants of offering grab bags with random mystery items sold at a deep discount. Even stores as large as Apple will offer mystery bags and they can contain big items like laptops. Traditionally these bags are sold around New Year’s, but are sometimes available before and around Christmas.
Here in the US, we don’t have as much access to deals like this and many times there isn’t much hope for items that are useful or valuable. My theory is that if you really want a chance of getting something worthwhile, stick to a site that normally sells items of interest to you unless you are curious in some real randomness. For some mild entertainment check out the Meh Kickstarter campaign where they offered Fukubukuro bags as rewards. Then look up the forums where people post about the stuff they got.
When looking for parts or ideas for my projects I usually check out sites like Adafruit, SparkFun and SainSmart. They each offer various Arduino compatible hardware and a variety of their own specialities. For three years now, SainSmart has offered Fukubukuro bags in various price points for the last few years and I have enjoyed participating albeit at a smaller, low-risk level.
In 2015, I tried out the $60 bag and got the following items:
|Item||Approx. Value at the time|
|Nano v3 Starter Kit||$40|
|Raspberry Pi case (x2)||$6|
That is over $100 value based on the retail prices at the time and most of it is useful to me in some way (I like the idea of NFC, but I am still trying to find a really fun or useful application for NFC).
In 2016, I ordered a $40 bag and a couple 3D LED Christmas trees (I’ll write about that experience in a separate post). I don’t know why I spent less that time after being so successful the first time. I didn’t take notes like I did the first time so I am not certain of the value at the time and if this is everything, but here is what I know I got:
There might have been something else in there, but I have since forgotten. The laser meter is quite handy (during those times I remember where I put it last.) I have no idea what I will do with the scientific calculator. The mini arduino will be useful at some point, although it has sat forgotten the past year in the box with the LED trees.
Last week, I got the notification that they were selling bags again this year. They are offered in three different sizes (Basic for $60, Advanced for $110 and Premium for $170) and this time they even provided some hints about items that could come in them.
The basic bag looks good but I have versions of almost all the tools mentioned so I wouldn’t get as much value. The premium bag has some really cool possible items, but they just don’t fit with what I have time for. The advanced bag on the other hand has several things of interest to me:
With these interesting options in there, I decided to order multiple bags to increase my chances of getting the items I am hoping for. I expect there will be certain duplicates, but some of those items I can put duplicates to use or find someone who would like them.
I plan to do a write up of unboxing (or is it unbagging?) of these once they arrive which should be some time this week. The shipment made incredible time from China to Anchorage via Cincinnati and has been handed over to USPS to make it the rest of the way to Juneau.
The circuit design is pretty simple. On the input side, there is a 510 ohm resistor to keep the current around 47 to 50 mA. If the voltage was consistent at 24, it would be on the low end of that, but it measures out closer to 27. This chip will take up to 60 mA, so there should be enough of a margin for safety. Initially, I tested the circuit before considering the power on the input resistors. .05 x 24 = 1.2 watt I only had quarter watt resistors on it, but they managed to work for a while with just a bit of discoloration from heat. Once I realized this problem, I disconnected everything for a while while I waited for the new resistors to arrive.
Cross posted from Blogger
For a while now, I have had this plan to monitor the energy use of our house–primarily the fuel oil for our furnace. Unless I go out to the tank regularly and check it with a dipstick, I have no idea how fast or slow we are using up the tank. The above ground tank holds 570 gallons and it lasts us around a year. Since we live in a temperate rainforest (and the water heater uses the furnace), the furnace is running year round. I only have a very rough idea of the difference between summer and winter usage. Last winter we decided it might save some oil to use a space heater, but I could not determine how much of a difference it made.
With this in mind, I made the following mental list of requirements for the first stage of this project:
I looked into several potential methods to measure the tank level.
There is really only one product already on the market that is similar to what I want: The Rocket. It is $120, only reads in 10% increments and just displays on the receiver. Without hacking the wireless protocol that is being used, there is no way to do automatic data logging and a 60 gallon granularity is not optimal for the analysis I want to be able to do.
Before I got around to mounting the EZ0, I came across a cheap version of the Ping))) sensor on eBay (2 for about $5 shipped). These sensors claim centimeter accuracy (about 6.5 gallons in the middle of the tank) and also cover the required range, so they were worth a try. I hooked one up on a breadboard and brought it out to the tank. I had to hold it most of the way in the whole, but it gave a reasonable reading: 116cm (about 46″ or almost empty; it was filled the next day). Once I verified that it would read properly aimed through a PVC adapter, I decided to go forward with this sensor.
The simplicity of this sensor is actually a bit of a strength. To use it, you pulse a trigger pin and wait for the echo on another pin. Even though its rated accuracy is a centimeter, accurate timing (and a bit of algorithmic cleanup) can allow for even better precision. More on the output later on in the software section.
To hold the sensor in place, I cut a disc out of a plastic container and made holes to fit the sender and receiver through. I started with a #5 plastic container which was quite soft and flexible and then changed out for a more rigid #7 plastic. Once I determined the sensor would not pick up the sides of the PVC, I started putting everything together.
I used CAT5 to run into the crawl space of the house so there are minimal components outside to weatherproof. I added an LED for a visual indication that the system had power (and perhaps to ward off anyone who comes by with the idea of siphoning the tank).
I tested out the system over the full 100′ spool to make sure that it wouldn’t suffer from any issues due to distance. Ultimately, I used closer to 20′ to get into the house and it would have been shorter but I already had a hole around the corner to use. I added in a temperature sensor, but I had to use an LM35 I had sitting around because I broke the leads on my TMP36. I don’t expect most people will know the difference, but basically the LM35 requires a negative voltage in order to read below freezing. I don’t have any parts around to produce the proper voltage, but I left the sensor in anyway. Even above freezing, I am getting erratic results, so I intend to replace it (when the weather is a bit warmer) or use a separate temperature sensor. I have tinkered with intercepting the signal from our Oregon Scientific weather station, but I haven’t had any luck yet (possibly, I need to add an antenna but that is for a different post).
While this project is in stable operation, it is not yet complete. Besides the improvements just mentioned, I would like to add active anti-theft of some sort. A couple ideas I have are a tilt switch on the fill cap and a motion sensor and there may be other features I come up with later so I will revisit this part of the system after I get some of the other systems functioning and have some more parts.
Coming soon: Part 2 – How to Audit a Furnace
Update: added a couple commercial sensors to the list.
Update #2: Here is a snippet of messy data before purging. The values jump all over the place, but the maximum distance read is often in line with what it should be. Once I removed the sensor and blew it clean, it continues to read fine for a while. This time I couldn’t see anything on the sensor.