On this podcast, on this session, I’m going to answer a question from Christi. There was a question about Arduino power consumption, and he’s trying to do some calculations for his own project, so I’m going to cover that. After that, I’m going to talk about comments that I received about the final assembly of RECAP, which was one of the postings at the blog. Again, the blog website is gadgetmakersblog.com. Finally, I’m going to talk about some comments that I received regarding the project the solder fume extractor. So that’s the agenda for today’s podcast. I hope you enjoy.
Starting with Christi’s question. Christi, which I believe he is from Romania, his question is, “I’m trying to do an Arduino project for my final thesis. I must say, I’m new to this. The thing is that I’m stuck at powering Arduino via batteries. I want to calculate how much power does the circuit consume. I want to connect to Arduino board on IR transmitter (an infrared transmitter, that is), an IR receiver, a piezo speaker, and an XBee module and some colored LEDs. I want to know the power consumption on the circuit. Can you please help me with some advice?” That was the question from Christi.
My answer was, well, you can do the same thing I did on that project on the Arduino power consumption blog post, which is you break the positive of the circuit, of the five-bolt power supply coming into your Arduino board. I disconnected the positive and I inserted a multimeter in line with that, and I put the multimeter in the current measuring position. On the multimeter, you have a rotary switch that you can select between becoming a volt meter or a current meter. So all I did, I put it in current meter mode, and I put it in line with the circuit. That way, I know how much power it’s taking. And of course, you want to write some software so that you turn both the receiver and the transmitter on, as well the XBee module, so that you kno w those devices are consuming power when you do the measurement.
So that was the idea. But then Christi came back to me and said, “Well, I want to do the power consumption calculations instead. I don’t have the hardware parts yet. For now, the project is just in theoretical phase, and I wanted to work for 10 minutes, and I want to find out if a 9 volt battery will do the job, or six AA batteries.” Since Christi doesn’t have the hardware yet available, we need to be a bit more creative. It would be much easier to have the hardware available; then you could just measure and see what it is.
Not having the hardware available – and let’s assume for a second here you need to do some calculations, because if it’s for your thesis, you must provide some calculations in order for that to be acceptable. If that’s the case, what I recommend you to do, you kind of have to guess how much current each one of those devices, each one of those subsystems is going to consume. For example, the IR transmitter, how much current does that take? And the same thing for the piezo speaker and XBee module.
Couple suggestions for you: you could look into the data sheets of those components. If you Google the data sheet, you should be able to find one line item that says how much current it takes. What you do, knowing how much current it takes or knowing the internal resistance of the component, you can do the calculation. What I suggest – so each component, for example, the IR transmitter, the receiver – each one behaves like a resistor, you can think of. So each one is a load that’s going to draw some power.
One nice thing you can do is download a simulation software, SPICE simulation software, such as Tina. That’s a free emulator or simulator from Texas Instruments, but there’s plenty of other free alternatives out there. Tina happens just to be the one that I use more often. What you can do, you can go there and enter all those components. Each component that you’re trying to get a power estimation for, you enter as a resistor. So you draw up a resistor and you set up a value of that resistor. You’re trying to match what you see on the data sheet for that component. You keep adding all your components parallel, and then you run the simulation. You’re going to see the total amount of current coming out of your batteries. So that is one path.
Now, if you can get by without doing that calculation, what you can do is, having your objective here to have the batteries lasting 10 minutes or more, the easy suggestion is just put two batteries parallel, or as many batteries you need. For example, if you take two 9 volt batteries and put it in series, you’re going to double that voltage. But if you put them in parallel, you’re going to have the same 9 volts at output, but now you have twice as much charge. So if you put two batteries in parallel, you’re going to double your ability to supply power.
But if that’s not enough to get you to 10 minutes, maybe you can put three 9 volt batteries in parallel. That is extremely inefficient in terms of probably if you’re going to go to production with this product, you wouldn’t do this, but for an experiment that you just need to last for 10 minutes and you might never have to run this again, I’ll just try to go that route. Put batteries in parallel.
All right, Christi, I hope that answers your question. If that doesn’t answer, just send another message to me and I’ll see what I can do.
The next question that I got was a response to the video that I posted. The video was called “Final Assembly of RECAP.” RECAP is one of the devices that I funded in Kickstarter. It stands for Record Calls on PC. I posted a video showing how I take the circuit boards and I put inside of an enclosure, which is printed using a 3D printer, and what kind of work goes into making a circuit board and an enclosure and putting it all together. I got a comment from Justin. He’s the organizer of Arduino Minnesota, and that’s how I met him. Thanks, Justin, for putting that together. Really nice to see other people that are in love with Arduino and electronics.
His question is, “Looks like a bit of time-consuming process, but the final product looks pretty sweet. Do you own all the equipment you are using in the videos (3D printer, heat applicator, acetone, etc.)? Kudos if you find yourself using all of it enough to justify the cost. Are you splitting the cost with someone else?”
First of all, yes, it is a lot of work, and when you start a Kickstarter project, you have an idea what it’s going to take to fulfill it, but you’re never really sure. Going through a Kickstarter project, it is a learning experience. All the way from how to ship goods, you’re going to learn a lot. When you find yourself with a hundred packages to ship, you’re going to see that the process of going to the USPS website and filling one by one is pretty labor-intensive. So that’s part of the learning.
Probably in the next go around, or probably one of my priorities in these projects, it is to find someone else that can do for me. Find a company that can do all that work for me. What I committed in the Kickstarter project, I committed a delivery of November, so my goal is to get those units delivered. But in the meanwhile, I need to start looking for suppliers that can do injection molding, and as well that can integrate the injection molding case with a circuit board. So I need to find suppliers that can take some of the labor-intensive things that you see on my postings. Because my long-term goal is, of course, not to do one by one by hand, the way I’m doing now, but it’s to find a sustainable way to, after I finish the design and I do a proof of concept on the design, to have it done for me. Each Kickstarter project that I do, I get the building blocks, I learn the components, I learn the things that will get me there.
“Do you own all the equipment you’re using in the videos?” Yes, I do. The 3D printer, the heat applicator, and the acetone. The RECAP is my second project. I created the MICO Shield for Arduino before. When I created the MICO Shield, I had no idea how many people would buy it, if I would sell five MICO boards or 10, 20. But it ends up that it was 200 boards. So I thought to myself, “It looks like there’s people that are in the market for buying that kind of stuff, which is great.” So I did a quick analysis on RECAP, and I thought, “Well, if I try to sell the circuit board of a device that can record calls, the number of people that will buy it will be kind of low.” So I knew that I if take the RECAP circuit board and put it inside of an enclosure, it will be much more attractive of a product. I spent about $900 and bought myself the printer, because on my analysis, I knew the printer would pay itself off.
And that’s what happened. Once I launched the project, I think I presold about $10,000 worth of RECAP units. Of course, when I set the price of RECAP, I tried to pick a price that would pay for that investment, pay for the printer. So that’s how I paid the printer. I bought knowing that I could easily recoup the investment.
Now, the heat applicator, that is a soldering station, and I’ll post the information about it. I’d been using soldering irons, and I noticed that after a couple months, the soldering irons went useless, so I decided to spend about $100 to buy a better soldering station, one that you can replace the tips once they go bad. I know that even the cheap soldering irons, you can replace the tips, but sometimes they’re really hard to find, so I decided to buy one that was easy to find the tips on eBay or wherever. When doing that, I realized that if I pay an extra $20, the soldering station would come with a heater applicator. So that’s what I did. I just paid extra $20 bucks and upgraded my soldering station. But I must admit that for the longest time, I had the worst soldering irons. I did the weight things with them, but I’m so glad that I got this. It’s night and day, the quality of the solder, and the bonus feature of having the heat applicator.
Regarding the acetone, that I got from my wife. But then once I realized that it was pretty useful to have that for the 3D print jobs, I decided to get my own and no longer use my wife’s acetone.
I think that covers the questions regarding the final assembly RECAP. In summary, the final assembly RECAP, a lot of work, but definitely a great learning experience on Kickstarter and what it takes to deliver a Kickstarter. I must say that gathering the funds, having people getting your product, is not the hardest thing. The hardest thing about Kickstarter is actually the little tasks that you had no idea existed before.
Now going to the last question for today. It was a comment regarding the blog post called “Solder Fume Extractor.” In this blog post, I did a step by step how to use a simple computer fan and make something that can take those fumes from your solder away from you so you don’t breathe it. This is a comment from Justin Grammens: “Nice work, Igor. Thanks for sharing. What a great resource you have created for people to see what’s up with your projects and learn from your experience. It’s great to have you part of the local Arduino Minnesota community.” Well, thank you very much, Justin. I have a very good time going to those Arduino meetings, because it is a place that you see people excited about electronics, and it’s so good to share that enthusiasm.
One more thing. I have a blog posting that I try to capture the top 5 tools for Arduino. I think that blog post is called “Top 5 Arduino tools.” Let me tell what those are. These are tools that I use either in a daily basis or things that I’ve tried to do for awhile and couldn’t find the right tool for the job. Once I found it, I was so glad I did. I just want to document that. Other people working with Arduino can benefit from that. Actually, as a matter of fact, I say Arduino, but they are useful for other embedded systems, such as Beagle board, Raspberry Pi, or whatever. Just for embedded projects, for projects that have microcontrollers.
My top 5 is:
#1, the must-have tool is called PLX-DAQ Data Acquisition for Excel. This is a free tool done by a company called Parallax, and what it does, you can send serial data to an Excel spreadsheet and get your serial data plotted into an Excel chart. The reason I really like it is sometimes when you try to read the numbers in the Arduino serial output, it’s just not the same thing as seeing it as a graph. Imagine like a sine wave. It’s so nice to see that wave going up and down instead of just seeing the numbers. But what I like most, it’s so easy to use; you just open the Excel, run, start gathering the data from your Arduino. On Arduino site, all you have to do is do a serial command output and you can get going in no time.
Actually, if you go to the blog, gadgetmakersblog.com, you’re going to find my code in the bottom of the page. That way, you can gain some time and have code, an Arduino sketch that you know it works. So that is the #1 must-have tool.
My second must-have tool is called Terminal. The name’s kind of generic; doesn’t imply much. But in reality, the Arduino IDE Serial Monitor is very limited. It’s very bare bones, very basic. There’s some projects you might just need to go the next level. Things I like the most about Terminal is the capability of doing macros. For example, if you’re testing an Arduino application and you have to send a series of commands, you can just set a macro to that command, that string. If there’s a string with 20 characters, you would type up that string, just save it. So next time you need to send that, you simply press one button, and you can send that string. You can set up a number of them. Maybe about 10, so you can have 10 buttons in front of you. You can just click which macro you want to send, and it goes right away. If you used Arduino IDE, or Arduino Serial Monitor, every time you have to maybe copy from a WordPad, from Notepad, and paste into the Serial Monitor. It’s very labor-intensive.
Other thing you can do in Terminal is you can program a message to be sent to Arduino at a determined rate. For example, you want to send a message every one second, like a heartbeat message, you can do that in Terminal. You just go to the button “Set Macros” and you can set that option. Very easy.
One other feature that Terminal has is the ability to see your data in different formats. You can see decimal, hexadecimal, binary, all at the same time. Sometimes when you’re doing data conversions and you’re not quite sure if you got the data conversion right, you can just open up in Terminal and see the raw data. So you can see what exactly Arduino is sending in both decimal, hexadecimal, and binary all at the same time.
The one feature that I don’t like about Terminal, I couldn’t get the plotting feature to work. Maybe one day I’ll spend some time and get that to work. For now, if you want to do plotting, just use the Parallax Data Acquisition for Excel.
Tool #3: Notepad++. There’s one reason I like it, which is sometimes when you’re working on a code for too much of a time, you can get lost amongst too much code. Notepad lets you zoom in and make the text bigger so you can focus on a more specific part of your code. Other thing you can do is the ability to collapse functions, so basically instead of – when you’re done working in one of the functions, you just collapse that and kind of get it out of your way so you can focus on the subset that you’re currently working.
One more feature about Notepad++ is the ability to add plugins. There’s a couple plugins that I really like. One of them is the HEX editor. Once in awhile, you need to open files that are in the hexadecimal format. The reason you know it’s in the hexadecimal format is that when you open that file in Notepad, it looks like gibberish. You cannot read it. But if that’s the case, you need a HEX editor. I know that you can find more powerful HEX editors out there, but I like the one in Notepad. Actually, what I do is set up my computer to open every text file or every Arduino file or C file in Notepad, so that’s my common platform. When you do that, you have that option to look into the HEX format.
Tool #4: Fritzing. Tool #4 is called Fritzing, and Fritzing is a tool to document your project. To be honest, I never used the tool. I downloaded it once, I try to use it, but I never end up using it. But the reason that I recommend is that when people have questions about projects, if you’re going to write about it, sometimes it’s hard to put all the pieces together. If you need help for your project, it’s much easier if you document in a schematic format into a visual format and ask for help. That way, the person helping you can very easily see what you’re talking about, what circuit you have, and can help you in no time. Even though I don’t use that tool for documentation, I really encourage people using it, especially if you’re going to ask someone else a question. If you’re going to ask someone else a question, just show them the schematic and/or the visual representation of the circuit. It’s much easier to answer questions that way.
Tool #5. At this point today, I don’t have that tool. That’s an open spot. So I need your help to decide what tool #5 is. Send your comments, leave a comment to this podcast, and I’ll look into that tool. And if I agree with you, I will add it as #5. In reality, if you’re listening to this podcast after I came up with #5, I’m going to leave your comment in the blog so other people know what are other great tools out there. And maybe one day, I’ll create a Top 10 Tools.
All right, that’s all I have for today for the first podcast. I hope that you enjoy; I hope that you were able to get a good feeling of what this podcast is about. Since this is the first podcast, the format in the future ones might change a little bit, but you got the essence, which is it’s to talk about making electronics. That’s in a nutshell what the blog is about. Thanks for joining, thanks for listening to the first Gadget Makers’ Blog podcast. It was a pleasure to have you. Please, if you like the blog, please subscribe to it in our website and on the iTunes store, and make sure you share with your friends. All right, see you next time.
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Q1: In response to Arduino Power Consumption
Q2: in response to Final Assembly of RECAP
3. Overview of the TOP 5 Must Have Arduino Tools.
Open for voting! What is your favorite Arduino tools?
- TINA: SPICE-Based Analog Simulation Program from Texas Instruments – FREE