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制造商零件编号 145335-1
OPENING TOOL 5-PACK
iFixit
Smart Woodshop Dust Collection with Home Assistant
2024-08-30 | By Zach Hipps
License: See Original Project Misc Hand Tools Programmers Raspberry Pi
My workspace is divided into two spaces. Most of the time, you'll see me working on the side where I'm working with electronics and 3D printing. However, occasionally, I need to come over to the other side of the shop and use woodworking tools. Each time I use one of the woodworking tools, I have to remember to turn on the dust collection system. If I forget that, the whole room fills with fine dust particles, and I don't want those getting into my lungs. Back in early 2018, I built a shop vac auto switch. I could plug in any tool alongside my vacuum and as soon as the tool would turn on the shop vac would also turn on collecting all the fine dust particles so that they didn't end up in my lungs. It was a very simple design, but it had one major limitation. The tool and the shop vac had to be plugged in at the same location. Ever since I completed that project, I wanted to do a second iteration where a shop vac or even a dust collection system could be controlled independently by any tool across the room, instead of using a current sensor read by an Arduino board which then controls a relay module like I did back in 2018.
This time around, I'm going to use a smart plug. This is the Sonoff S31, and I chose this smart plug because it can measure the power being drawn by the tool plugged into it. Another reason I chose the Sonoff S31 is because it uses an ESP Wi-Fi microcontroller. I can write and flash custom firmware on this device to get it to do whatever I need. Before I can flash this with custom firmware, it needs to be opened up. I'm going to use a little plastic opening tool, and I'm going to pry up on the gray side of the case. It should pop up and then once I've got that open, I can slide out two little white pieces. By removing those pieces, I can see and remove the screws below them. After the screws are removed, I can pull the cover off the S31, and that reveals a little programming header right on the edge of the PCB.
This is a typical UART programming header. It needs four signals: Power, Ground, TX, and RX. The most important thing to remember when programming something with UART, the TX pin on the programming side needs to connect to the RX pin on the target side. Likewise, the RX pin on the programmer needs to be connected to the TX pin on the target. Now I need to figure out the best way to connect those signals on the programmer to the Sonoff S31. I've got a few options here. A lot of tutorials on the Internet show people soldering jumper wires directly to these test points. That would work fine if you're doing a single one. I plan on doing many, and I think I have a much better solution. I picked up this little Pogo pin probe clip from DigiKey. It is perfect for this situation; all I need to do is to clip the Pogo pins over the programming pads. From there, I can connect jumper wires from the probe clip to my programmer. This is much faster and cleaner than soldering jumper wires to each board for programming.
I've gone back and forth on how I want to approach the firmware portion of this project. I've spent some time talking to some friends of mine, Ian, and Jonathan, who have more experience in home automation than I do. They recommended that I get a Raspberry Pi and install Home Assistant on the Raspberry Pi so that I can start setting up this system. The best way to get an ESP microcontroller like this to talk with Home Assistant is by flashing a custom firmware called ESPHome. Now that I have Home Assistant installed on the Raspberry Pi and ESPHome added as an add-on within Home Assistant, I can go to the dashboard and click on the “+ New Device” button. From there I'll name it “table-saw” and I'll click continue so that it creates a basic configuration. This basic configuration creates a YAML file. The YAML file is just a text file written in a markup language, and it tells ESPHome exactly what to do to write the firmware for my device. Fortunately, I don't have to write this YAML file from scratch because if I go to the ESPHome website and search for “Sonoff S31”, there's already a complete configuration file written for it. I'll copy that entire configuration file and go back to ESPHome, click on my table configuration, and click “Edit.” This opens up the current YAML file. Next, I select all the current configuration text, delete it, and then paste the new Sonoff S31 configuration. The other thing I want to change is the name of this device. You want a unique name for each device on your Home Assistant network. I'm going to name this “table-saw”, then I can save the YAML file and then the next step is to compile this into firmware that will be loaded onto the device.
To do that, I'll click the manual download option and that will compile the binary. Once it's done, it will save it as a binary file on my computer, and then during the next step, I can load that onto the device. Depending on the hardware you have running Home Assistant, this can take quite a while. In my case, I'm running a Raspberry Pi, and compiling code can take 20 or 30 minutes sometimes. Now that I have a compiled binary file saved to my computer, it's time to upload that on the ESP device. I'm going to use ESPHome Web. This next step can be tricky. I'll hold down the button on the Sonoff S31 while I attach the probe clip. This will put it into bootloader mode and get it ready for us to load the code file. I can't release the button until it has started to program. I'm going to click “Connect,” choose my com port, and then click “Install”. Then, I'll browse to the location where I saved the binary file, and with that file selected, I'll click “Install”. Now it's connecting to the Sonoff S31 and it is installing. I can let go of the button. This is the step where the binary file is transferred through the UART programmer into the Sonoff device. Now that the configuration is installed, I can click close, and go back to Home Assistant. If I look at my device, I can see that it's offline. To fix that, I need to do a power cycle. I'll unclip and re-clip my probe just to power cycle. After a couple of seconds, the status changes to online. That's pretty much it. This device is programmed, and I can put it back together and start using it.
I'm going to have several of these devices throughout my shop, and I want to be able to keep track of them. I'll use a label maker to print a label for each one. The Sonoff S31 is now reassembled. I'll plug it into an outlet strip for testing purposes. I’ll go back into Home Assistant, look at my notifications, and see that a new device was discovered. It asks me, “Do you want to add ESPHome node ‘table-saw’ to Home Assistant?” Yes, I do, click “Submit”. Now I can go into the dashboard I set up for my dust collection, see that the table-saw relay is there, and I have a little button I can click. If I listen carefully, I can hear it click when I press the button. Now I can control this relay from Home Assistant, which is a huge milestone for this project.
Next, I want to test to see if current or power is flowing through the Sonoff S31 when I plug in a tool. It's not practical to drag my table over here, so I'm going to use a jigsaw and I'm going to plug it into the Sonoff plug. As I pull the trigger, I expect that power to show in Home Assistant. When I pull the trigger… awesome! The power went up to about 300 watts as I was pulling the trigger.
The next step is to do this all over again. I'm going to program a second Sonoff S31, but instead of making it a tool like I did last time, this time I'm going to name it “dust-collector”.
I'll plug this in across the shop just for demonstration purposes to show that these don't need to be right next to each other. The whole idea is that I want my desk collector on one side of the shop, and any tool around should be able to turn that on. I'm going to go plug this in, and then plug in my shop vac for now. It's loud enough that I'll be able to tell when it turns on. Like before, I see in my notifications that I have a new device called “dust-collector.” I'll hit configure and yes, I want to add it to my Home Assistant. Once again, I see that the relay button shows up on the dust collector along with all the other power-measuring information. I'll test that relay and see if I can hear the dust collector turn on. Okay, that worked!
Next, I need to create an automation so that when the tool turns on, the dust collector also turns on. Then, when the tool turns off, the dust collector turns off. To create that automation, go into Home Assistant and click “settings” and then on “Automations and Scenes.” Right now, I don't have an automation, so I'll create a new one. First, I need a trigger. Click “Device,” select “table-saw”, and select the “table saw current”. In the “Above” field, I’ll put 2 so when it changes above two amps, I want to turn on the dust collector.
So, let's try that out. The dust collector turned on when the current went up over two amps! But there's a problem. When the current went back down to zero amps, the dust collector was still on. I need to fix that in the automation. Now my automation has two triggers. If the table saw current goes above two amps or it goes below two amps, it will then go to the actions. If the dust collector relay is already on, it turns the relay off. Otherwise, it turns the relay on.
Let's test that out again. When I turn on the table saw, the current will go above two amps and it'll turn on the dust collector. As soon as I turn off the table saw that current falls below two amps, so the dust collector should also turn off. It worked! The dust collector turned on and immediately turned off as soon as the current dropped below two amps.
Now all I need to do is just program more of these Sonoff S31s, add them to each of my tools around my shop, and then create automations so it turns on the dust collector when the current goes above a certain threshold.
Over here in my woodshop area, I'm going to plug my dust collector into the Sonoff S31 that I programmed for it. Then, I'll plug my table saw into the Sonoff S31 that I programmed for it. With both of those things plugged in, I'll make some test cuts on my table saw and see if the dust collector turns on automatically. I also programmed Sonoff S31s for my miter saw, band saw, and random orbital sander. Whenever I use these tools, the dust collection system should kick on automatically.
This is an awesome addition to my wood shop because it keeps my lungs protected, and I don't have to remember to turn it on manually… but it's missing something, and that something is blast gates. Next time, I'm going to show you how I designed and built automatic blast gates that open and close when the tools turn on. That way I don't waste suction in the areas of the workshop where it's not needed.
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