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:
- The big item in there was a laser measuring meter (similar to this one but in red.)
- A scientific calculator
- An Arduino Pro Mini, but it does not appear to have marks to indicate what frequency or voltage it operates at.
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:
- The self balancing robot definitely looks cool
- I like the 8″ LCD screen for Raspberry Pi–I am sure I could put that to use
- I am curious about the smart soldering tool since my portable soldering iron is pretty old and very basic
- RetroPie game kit–I have one, but this includes the SNES controllers and I can use an extra Pi 3
- LCD touch display for Raspberry Pi. Maybe this would make a good addition to the 3D printer.
- 21 segment VU meter tower would be an interesting project
- A non-contact AC voltage detector (I could have used one a few times in the last couple years, but I haven’t brought myself to buy one yet)
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.
As a follow up to Part 1 on consumer-level electronics, I decided to summarize games and game related campaigns I have been interested in. I am including puzzles as well since they don’t really fit in any other category.
Robot Turtles (Sept 27, 2013 KS)
Goal: $25k Raised: $631k Pledged: $29 Delivery: Dec 2013
This has been my favorite game related campaign I have seen yet. The initial concept was a way to entertain his kids and learn analytical skills. Most games targeted at kids are based purely on chance and teach very little. Candy Land is simple card turning and getting stuck in Molasses Swamp is just frustrating for kids. Chutes (or Snakes) and Ladders is just randomizing every player’s location until someone gets lucky enough to hit the end. Games like Connect Four have been solved, meaning like Tic Tac Toe, you can always win if you make the first move.
In this game, designed for 3 to 8 year olds, each player uses cards to issue commands to their turtle and an adult executes those commands (goofy sounds are encouraged in the rules). Some of the stretch goals added more features such as ice walls that can be melted with lasers and boxes that can be pushed out of the way. These features are designed to be added in as players become more familiar with the game. Another way to add challenge is to have players set down the complete set of instructions first and then move the turtle. I really like the way that the game can grow and it is flexible enough to modify the rules even further.
We received our copy of the game last week and the quality is just as good as any other game out there. The parts include the board, 4 decks of cards and numerous double-sided, heavy stock tiles (similar to Carcassonne tiles). My 3 year old son doesn’t seem quite ready to focus on the rules, but it is still pretty new and exciting. He does love moving the turtle through a maze of walls to get the gem, so he intuitively picked up the basic goal with little prompting. As one of the stretch goals, they will be releasing some “adult” rules (called Galapagos) to add increase the challenge for older players, but I have not yet seen the details on the differences.
There are currently no future plans to continue printing the game. The goal was just to get enough quantity to make a quality game at a decent price. Maker Shed did pick up a number of copies to sell and if there are any left they can be found here. It is likely they will disappear since they only ordered 1500 copies and there was a mailing list of over 4700 people that were going to be notified. Other than that, this game is now out of print unless he decides to publish again. I personally hope that it gets picked up again because it I think it is an excellent learning tool. My company just participated in the Hour of Code campaign where we go into schools and help introduce kids to programming concepts and this game immediately came to mind.
Maze of Games (March 14, 2013, KS)
Goal: $16k Reached: $171k Pledged: $60 Delivery: June 2014
This project is a one of a kind puzzle novel with numerous contributors and amazing looking art (what they have revealed at least). Even the campaign itself included a number of puzzles to solve by scouring any text, images, video and even music and finding hidden clues in related blog posts. I found the challenges very entertaining and I expect the book to be even better.
I pledged enough to get a hardcover copy, digital copy and an additional foldout maze puzzle. They are not currently taking new orders, but it is possible they will sell more copies once they finish printing. There were numerous stretch goals setup that added additional puzzle artists to the book. I believe it was this increased scope that has slowed down publishing with the extra editing and artwork. The latest update was that they would not arrive by Christmas as hoped, but I don’t mind too much because I know it will be a high quality book. For those that were intending it as a present, they are providing a card that even includes another puzzle that I still have to solve.
Goal: $900k Reached: $974k Pledged: $20 Est. Delivery: July 2014
Armikrog is a point and click claymation adventure game from the makers of The Neverhood. This time they have decided to self publish their new game. They recruited Mike Nelson (of RiffTrax and MST3K) to voice the main character which is what first got my attention. They are hoping to get onto Steam–you can help by voting for it on Steam Greenlight. They will also be making a Wii U version with some special features that take advantage of the second screen. For anyone who would like to get a copy of the game, you can preorder at armikrog.com for $25 or even get many of the extras.
The X-Cube (July 7, 2013, KS)
Goal: $30k Reached: $53.8k Pledged: $5 Delivery: July 2014
The X-Cube is an expansion of a regular rubik’s cube, but still different from the 5x5x5 cubes. The prototype was created on a 3D printer and since I will soon have a 3D printer, I put in enough to get the model files. These files were provided shortly after the campaign ended and they real ones were estimated to be out in October, but are being shipped out right now.
Goal: $1k Reached: $14.5k Pledged: $15 Delivery: Oct 2012
This project was kind of a no-brainer for me. We like to try games and the goal of this effort was to get some additional copies out to an audience that would provide some feedback. The game was already printed, so there was no delay in delivery and the price pretty much just covered shipping. We have tried the game out and it was pretty fun. I don’t know if it will replace our current favorites, but it is one we will hold on to.
Hexels (January 21, 2013, KS)
Goal: $50k Reached: $130k Pledged: $75 Delivery: Jan 2014
Settlers of Catan is still one of our favorite games, but the board setup isn’t perfect. The frame can take some fiddling to get it to stay together and it gets harder with larger layouts like Seafarers. Some friends of ours have border sections that seem slightly warped such that the inside edge raised up from the table and wouldn’t hold the tiles at all.
Hexels provides one solution to this problem by creating mini frames that fit around each tile and hold together with magnets. The tiles can be stored with the hexels, so everything can still fit in the original box (with the plastic insert removed). I have enough coming to cover 3-4 player Seafarers (to get the 10 additional ones for 5-6 player was too big a jump for me since I missed the early bird price for that level).
There was a significant delay in getting these out due to getting the plastics right and the injection molding process down to make them durable and looking nice. I opted for assembling the magnet covers myself to get them sooner. We have now played several games using these and they are great. The only thing missing is something to hold the ports but I could probably design something to 3D print. The project owner was very forthcoming with information with video updates almost every week.
Catan Board (November 19, 2012, KS)
Goal: $25k Reached: $361k Pledged: $100 Delivery: Aug 2013
Before the Hexels showed up I came across the Catan board. This is the only Catan accessory that has been officially licensed by the publisher of Catan. Pictured above is the plastic version (with one possible color theme they considered), but they are also selling a bamboo version. For the Kickstarter campaign, they made a limited number of walnut and aluminum boards. I have already received the basic 5-6 player board and it is very nicely made. They will soon be sending out the Seafarer extension pieces and card holders that were added as one of the stretch goals.
The main problem that caused delays is getting the injection molding right. First there were problems with the molds, then the injection process had to be tweaked. Along the way they provided information about what was going on and I learned some things about plastic injection molding from that. They had some issues toward the end about the finish of the plastic–whether the pieces could be painted nicely or just bare plastic. The two tone color scheme did not work out for the manufacturing process, but they did provide some information on a good way to paint them.
The Keep (October 31, 2012, KS)
Goal: $250k Reached: $58.6k
This campaign was an interesting solution to store and transport games. The picture above was just part of the system called the Great Chamber. There were also plastic containers that were good for cards and smaller one for the various chits and small pieces. I liked the concept, but I wasn’t totally happy with the price point for a complete system ($120 for the options I wanted). While this second Kickstarter campaign reduced the original scope and reached a lot more people they did not end up reaching their goal. Despite this, they have continued to refine the design and even make the Great Chamber modular. I am not sure where the product stands right now because nothing has been posted on their Facebook page since July.
- Inductive coil – these are great for measuring current on a high voltage line, but they are a bit more expensive than I liked and I only need to detect on and off. I could build one, but it will take a bit of tinkering without an AC power supply for testing. There are split core sensors that can be clipped over a wire, but they run more than $8 each.
- DC power adapters – It is possible that I could find an adapter, but there aren’t a lot of options that run on 24 VAC.
- Optocouplers – these are built specifically for the purpose of interfacing high and low voltage systems without directly connecting them electrically.
- Hall effect current sensor – kind of a cross between optocouplers and inductive sensors. The current is passed near a sensor that senses the amount of electromagnetic force.
- 4x IL250 (I got 5 for about $8 on eBay)
- 4x 510 ohm, 2 watt resistors (input current limiter)
- 4x 220 ohm resistors (output current limiter)
- 4x LEDs (The diagram shows red, but I used different colors-more on that later)
- 4x electrolytic capacitors
- speaker wire for furnace hookups
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.
- As I mentioned, the voltages are opposite of what I thought I remembered from probing. The data logging side is fixed through software, but I still want to rework the circuit so the LEDs operate correctly.
- I still have an issue with it starting up with it registered through update-rc.d, so I used rc.local to force it to startup instead. I may look into it at some point, but this method is working for now.
- The thermostat terminals on the furnace controller aren’t as useful as I had hoped. This connection tells the controller unit that heat is needed, but is not a direct indication that the furnace is burning. Somewhere in the controller, it starts and stops the furnace to keep the water between the set temperature range. I have a few ideas to monitor actual burner operation, but I will continue to look into it and cover this in a later post when I have some options detailed out.
- The day after I got all the wires hooked up, the Pi became unresponsive on the network. Following this post, I put in a script to monitor the wireless connection and reinitialize it when it drops. So far this seems to have kept the Pi on the wireless.
- One oddity that shows up in the data is a 10 second on time after each zone valve has been off for roughly a minute. I considered that something is causing the zone valve to miss its stop point and rotate again, but it shouldn’t take a minute to get back around. I will ignore these 10 second results and look into this phenomenon further.
- I may try using Dropbox for updating the web pages instead of FTP.
Cross posted from Blogger
It has been a little over a year since I got into Kickstarter and I thought I would collect some of my thoughts on the campaigns I have pledged to. In addition to Kickstarter, I have backed a few things on IndieGoGo which operates a little differently.
On Kickstarter, you pledge any amount you wish, but there are defined reward levels. If the campaign fails, you do not get billed for the pledge amount. IndieGoGo can operate the same basic way, but you pay the amount up front. Some campaigns have fixed funding goals and if they are not reached, you get refunded. They also have flexible funding campaigns that don’t fail if they don’t meet the goal (though the creator is penalized for this). Some IndieGoGo campaigns can even extend their end dates–I followed one that did this to allow more people the opportunity to get in.
This post is dedicated to the the non-development electronics and I will post about other types of items in future posts. Part 2 will probably be on development electronics since that is one of the biggest categories I participate in.
ZPM Nocturn (missed out on backing, but preordered)
Equiso (July 28, 2012, KS)
The Equiso was the first kickstarter campaign that I supported and what drew me into getting started pledging. I saw this as a great way to play video on a TV without needing a computer. My intention was to use the Plex app to watch videos on the TV in our bedroom. The estimated delivery date was for August and I received it mid-October which isn’t too bad for a product of this scale.
Initially, Plex would run but not play videos. Since I didn’t intend to use it for games and such, I didn’t get much use out of the stick for a while. However, the remote has been very useful. They changed the design to use a removable USB receiver for the remote so I was able to plug it into my media computer and control the Windows Plex app that way.
I still use the remote almost daily with only one complaint: the USB charge port broke off of the board making it really difficult to get it charged. The first time, I disassembled the remote and was able to resolder the plug. Just recently, I had to fix it again and I tried some super glue as well. I’ll see how well that does.
In August, they offered to update the stick for the new model. All I had to do was send the original one and keep the remote and power cable. I should have included tracking because it ended up lost somewhere, but they were gracious enough to send me the new one once I sent them a copy of the postage receipt. I am happy to report that the new model runs the Plex app beautifully and as long as I leave it running I can control it from my phone. The only wrinkle now is that Plex has added ChromeCast support, so it may become the more optimal device for my purposes.
Ouya (August 9, 2012, KS)
ChargeCard (August 27, 2012, KS)
Mini MicroSD Reader (May 5, 2013, KS)
MyPhone Thermometer (Failed, KS)
Beddit (October 15, 2013, IGG)
This campaign did have the end date extended just to let more people get in. The estimated delivery was going to be November, but they got held up by Apple certification on the BlueTooth. Since Apple has to approve the hardware part, even us Android folks are still waiting a bit longer.
World’s first roast-grind-brew coffee machine (December 8, 2013, KS)
Angel band (didn’t back, but watching)
Update: I added links to the campaign pages and goal stats.
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:
- oil tank level sensing
- enough granularity to see daily usage
- data logging
- ability to compare oil usage to outside temperature
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.
- Mechanical – while this style of sensor should be very simple and reliable, I didn’t come across any that could be read digitally or were able to read a range of 4 feet. One may exist, but I suspect they would be fairly expensive.
- Resistive – While strips exist and provides continuous range, they are not even close to being long enough.
- Capacitive – There are also capacitance based strips, but they are also too short so I would have to build and calibrate my own. I also had some concern about a capacitive sensing in fuel oil, but I later learned that this type of gauge is used in some aircraft so it should be safe. Probably better safe than sorry.
- Gravitational – Strain gauges are solid state devices that measure weight and are used in scales of all sizes. I was not sure how hard it would be to get them placed under the tank, so I did not research them very much.
- Optical – Infrared distance sensors seemed like a simple option, but I didn’t find one that covers a broad enough range for my purpose. They all seemed to be designed for close range or far range
- Ultrasonic sensors – there are a lot of different ultrasonic sensors. There are expensive industrial models and cheap ones that are often used in hobby robotics. After looking at several different sensors, I picked up a Maxbotix EZ4 (more on these later).
- Others – I considered a sensor based on light diffraction, but I don’t know how one would work on a tank like this. There may also be some sort of resonance type that could read from the outside of the tank, but I would guess these would need a bit of calibration if something does exist.
- I also thought about putting a flow meter on the intake line, but I would also have to have one on the return line and it would not really tell when the tank was getting empty.
- Thanks to hackaday.com comments, I was pointed to the Jaycar and the Centroid sensors. The Jaycar needs a half meter of head space–I think it is intended for upright tanks. Like the Rocket, it uses its own receiver. The Centroid is hard to find a lot of information on (especially price), but I believe it is a capacitive sensor that can be cut to length.
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).
- As I mentioned already, it is not very convenient to bring the laptop down to the crawl space to update the Arduino code. In addition to that, the jumpers on the XBee shield are not working for me, so I have to disconnect power, carefully remove the shield, plug in the USB to upload, disconnect USB, reattach the shield and plug the power in again.
- The XBees (at least series 1) are simple to use, but they don’t quite operate the way I had planned. My hope was to use one receiving module with several senders, but they are designed to be one to one communication. There may be a way to set one to promiscuous mode, but my current plan is to change out the Uno board for a Spark Core which should be arriving soon. These boards have integrated wifi and can be programmed over the Internet.
- The XBees also don’t have the range I had hoped. I had to move the receiving end as far from the computer as possible to get them somewhat reliable.
- Sometimes the data jumps around a bit which can be seen on the graph image above. There are also times that the sensor gets a drop of liquid on it causing misreads. I have done some cleanup of outlying values, but the moisture problem is not apparent yet. It could be a bit of condensation, but I suspect it is a stray drop that splashed from the return line. To fix the problem, I have pulled the sensor off and blown it clear each time. If the problem goes away as the tank gets lower, I will assume it is splash back, but I haven’t formulated a permanent solution yet.
- As I mentioned above, the temperature sensor I included doesn’t provide any benefits as it is. I won’t change it out until the weather is warmer, but if I come up with an easy way to generate a -5V, I may do some more testing in the meantime.
- I forgot to do a manual measurement to calibrate the distance from the sensor to the top of the tank, so I made a rough guess. This could make the values off, but I can adjust the head space on the database side if I decide to. In the future, I may make this a setting on the Arduino side that I can modify over serial communication.
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.