automation

3D Print Automation with Dreamer-based Printers

I recently created a network proxy for the FlashPrint software, which makes remote printing via Wi-Fi possible with the PowerSpec printer. While debugging that setup, I was able to observe the exact protocol and undocumented gcode commands used to send a file to the printer for printing. FlashForge doesn’t “stream” a print like many support with a tool like Octopi. Instead, a set of gcode commands are sent to the printer and then saved to the printer’s memory. Finally, then print begins. Since I can’t use Octopi with the FlashForge proprietary gcode, I needed something else.

Automation Option

The first goal was to enable automation for using another slicer. I created a set of Python functions to send a file to the printer. From there, I had what I needed to setup an Automater script on my Mac. This script monitors files in a directory and when one appears, it invokes the script with the filename. The trigger is files or folders added to /documents/start3dprint. The action is to run the shell script, passing my printer’s IP, port, and filename. This has worked well to start printing directly from Simplify3D

Print Monitoring

I also wanted an easy way to keep a window up in the corner of screen with print status. For this I created a simple Python GUI to connect to printer for monitoring and/or send a file. This can be used in conjunction with the automation to monitor print progress. I was able to compile it into a windows executable and Mac .dmg file. I was surprised how well the UI toolkit and compilation worked.

I hope after some more testing I’ll feel comfortable releasing it to others to try.

Using OctoPi with USB Camera

OctoPrint is an amazing little app with a simple web interface that controls your 3D printer. It has the ability to manage your gcode files or even take STL files and “slice” them into gcode files (which I’d never use since I like to visualize the layering in a tool first). OctoPi is a Raspberry Pi distribution of the tool that runs on the Pi. I had an older Raspberry Pi B that was perfect to throw at my need to remote control/monitor my longer 3D prints.

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View of interface on iPhone

Disclaimer: I know the Raspberry Pi camera using the camera interface is “the way to go”. But an older camera you have (or $5 Playstation Eye camera) is worth a try right? No way, CPU will be too high, you won’t have enough USB ports, system will run too hot, will cause printing to pause … or will it?

The way OctoPrint integrates with a camera is by pulling into its page a video stream from mjpg_streamer (a web server running on a different port). This tool takes content from your web camera and creates a web video stream.  This software is distributed with the OctoPi build, no extra install required. Building the stream is a much more efficient if your camera is newer and has support for MJPG – otherwise you’re using YUYV encoding and the Pi has to do a lot of extra work. Nevertheless you can make this work. I use the following options to run the streamer:

./mjpg_streamer -i "input_uvc.so -f 1 -q 50 -y -r 640x480" -o "output_http.so -w ./www"

The important parameters above is the “-f 1” which says do one frame per second (I’m not looking for high quality video – I just want to see if print has lifted and get a feel of progress). The “-q 50″ controls quality of the result compression.

You can update settings in /boot/octopi.txt so these are used by default. This can be done by ssh to your machine or shut the machine down and edit the file on your computer after putting in the SD card.

camera_usb_options=”-f 1 -q 75 -y”

The advantage of changing the settings in the boot config file is every time you unplug the camera the process dies, and when it starts it will use this setting (there is a background process called “webcam” that handles this).

I tried changing the resolution and surprisingly  didn’t find a change in CPU usage so opted to keep it. As far as CPU, the system is running high at 85% and most of that usage is from the mjpg_streamer process.

Command to check temperature:
vcgencmd measure_temp

So yes, it runs the CPU pretty high (80%+) and the temperatures run a few degrees higher (but at 54’C well below limits), and the initial OctoPrint interface loads a bit slower. If you don’t want to spend money on a $30 Pi camera or a more expensive USB camera I think you can make it work.

Useful Documentation Page on Settings per Camera

Raspberry Pi – Under Voltage or Temperature Issues

IMG_0423Step number one for ANY Raspberry Pi issue is “check the power supply”! Many issues on the Pi come from improper power; SD card corruption is a popular one. Often, people, including me, try to use an adapter with a Micro USB cable. Even if the adapter is rated for 5+ volts and 2.5A (for Pi 3), the quality or length of the cable might limit the power it can draw. For this reason, some people recommend a corded power supply, typically one from a “trusted source” like Adafruit. Despite using the “right” power supply on my two Model 3B devices, I was seeing under-voltage warnings (rainbow block) and at one point, a temperature warning. One was using an Adafruit supply and the other an iPad supply (both higher rated and with a nice thick cord). Both are in a cheap case I got from MicroCenter.

The software I was using had a menu system with some video on the screen, and it was consuming about 50–60% of a CPU core. I was seeing temps in the 77-79 range with some CPU throttling. It was curious to me that this activity was drawing so much on the power supply that I’d get an under-voltage warning. I removed all USB devices to be sure nothing other than the Pi was using the power. Even when I swapped the SD card, Pi, and power supply, it was pretty predictable that after about 15 minutes of use, I’d see the rainbow block.

I decided to run sysbench to see if a much higher CPU utilization (maxing out all four cores) would generate much more heat. Interestingly, while it did heat up more quickly, the top temps were about 83-85 with some significant throttling to keep the temps at bay. Again, the under-voltage warnings appeared. To me, it seemed like the heat was triggering the under-voltage warnings.

Sysbench:

sysbench –num-threads=8—test=cpu—cpu-max-prime=10000000000 run

Temp/Throttle Monitoring:

watch ‘(vcgencmd measure_temp; vcgencmd measure_clock arm) ‘

Next, I ran a test at a much lower CPU utilization, but covered up the case to build up the heat, and after about 10 minutes, I got the rainbow block again. I wouldn’t think these minor changes in temperature would affect the voltage draw, especially given the throttling. I picked up a pair of cheap stick-on “Addacore” CPU stick-on heat sinks (yeah, I said stick-on). I repeated the same experiments and they clearly did their job. I saw a consistent drop in temps of about 4-5 degrees, which is more than enough to prevent the throttling and the under-voltage warning (which I’m not sure I believe). Even the system bench test had much lower temps and less throttle.

OK, it’s 3M tape. I would not mount this Pi vertically because I suppose if it got warm enough gravity might have its way with this adhesive and ruin the board, but it’s working great. No more high temperatures or under-voltage warnings. While I’m tempted to remove one of them and repeat the experiment and measure the voltage from the Pi with a meter, I’m going to leave well enough alone.

Anyway, if you are seeing rainbow blocks, check your power, but also check your temps and try a heat sink:)

My Experience and Review of Wink Home Automation Hub

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While shopping on Black Friday for my annual $1Home Depot poinsettias I ran across a great deal on the “Wink” home automation hub.  Wink was available for only $.99 if you purchased two home automation Products. Conveniently the GE link lightbulbs were only 15 dollars, Just a little bit more than normal LED bulbs.  I purchased two of them thinking this had to be the cheapest way to get started with home automation.

The GE lightbulbs look a little unusual. In addition to being a little bit larger than average they are clear at the top and you can see a small circular antenna for radio communication. Unlike some bulbs which have a diffusion layer to soften the bright LEDs, the GE bulbs are clear and can appear a little harsh. The first attempt I made was to take automate the lamp on a coffee table next to my family room couch. I screwed in the bulb, I turned on the light, and opened the wink application. Following the wizard my light was quickly available to turn off and on as well as dim with almost zero effort. The next bulb went in the ceiling over my kitchen sink. I repeated the same process with the same success. The next thing I tried was setting up a light schedule. For my family room lamp I wanted it to come on at dusk and go off at 10 PM in the evening. For the kitchen light I wanted it to come on at the same time and at 10 PM go to a low dimmed mode to function as a”nightlight”in the middle of the night. The obvious downside of this approach is that these are switched elements and so anyone can switch them on or off making them unavailable to your home automation hub to control. You’re probably wondering what the state is after turning it off – it’s like you hope and comes on normally (and reports to the hub it’s in “on” status).IMG_0071

It was nearly Christmas and I decided that my experiment was going well and Santa should bring me some more Wink-supported gadgets. I added a wall switch that would allow me to control all the lights in my living room and the Wink “Spotter” device which claims to detect many things including motion, temperature, humidity, and more.

I started with the Wink Spotter device and immediately ran into several problems. I tried on several times to get it to sync with my Wink hub and consistently got errors. Finally in a completely random effort on a later day it started working. Quickly I noticed the humidity and temperature controls were nowhere near any of the other temperature devices in my home. I have two other thermostats including a Nest thermostat and it reported very low values by comparison. Next I tried the light sensor hoping to trigger my lights aced on the ambient light in the house. While the trigger often noticed a change in light it was easily affected by other lights nearby I really couldn’t find a proper use for this feature. Lastly I tried the motion detector. Like many other Spotter customers I was surprised to find out that it doesn’t detect motion around it but instead detects its own motion. If you were to place the spotter BY a door it would never sense any motion you would have to hang the spotter with a cord ON your doorknob for it to actually detect motion at your door. Let’s just say that wasn’t exactly what I was looking for – but after reviewing the online videos and instructions it’s quite clear the spotter is meant for more unusual use cases. Some examples I found were things like determining when your washer is done or when the kids are jumping on the bed.  Given in accuracy of the sensors and the unusual implementation of a motion detector I quickly returned this Christmas gift to the store.

Thankfully the new quirky door sensors (Tripper) had just hit the market. I picked up two of the sensors for $40 on Amazon. So far sensors have worked very well however they eventually would lose contact with the hub and the only way to correct the problem was to restart the hub. I’m happy to report that the latest upgrade to my wink hub seems to have resolved this problem. These were great for automatically turning off or on the lights based on door action and keeping a log of entry. I now know exactly at what time my kids are coming in and leaving (don’t even try to lie to me)!

IMG_0072The Levitron wall switch is ideal and one of the best investments you can make with your Wink home automation hub if you have a lot of ceiling lighting. It was crazy simple to install, worked right out of the gate in the wink application, and provides a very nice LED friendly dimmable solution. Since there are no actual physical switches you don’t have to worry about your family turning it off and no longer being able to control the lights. At $50 it’s a little too expensive for me to switch all my lights to, but I hope to upgrade 1-2 switches a year.

I next decided to try to connect my Nest thermostat to my Wink hub. This was very easy to do and it seems the main benefit is you can make changes to your temperature from inside the wink application without having to launch another application. In addition, since Wink has geofencing  you can add robots to increase or decrease your temperature when you arrive or leave home – this is not a feature that Nest supports natively.

The last device I decided to try was one that isn’t certified yet with the Wink Hub (however it is a Z–wave device and generally supported by the Wink). I purchased the Aeon Labs appliance switch the which is essentially a small extension cord whose power can be turned on and off like a switch from the lights interface on your Wink application. I bought it on Amazon because I knew they have an easy return policy. Like every other device I hooked up this one worked instantly and was controlling it in under a minute. My only complaint is that it shows up under lights, I’m using it to control a small space heater in my office. The device also has the ability to report energy consumption but the Wink doesn’t support that either. For $20 it’s a great way to control just about anything and I’m very pleased with the product.

So it’s all rosy with the Wink right? Well not exactly. I’m more than a few occasions I’ve had to restart the hub because it stopped working completely. Since the last update I haven’t had this problem so I’m hoping it was a momentary software glitch. While the Wink Hub should support many Z-wave devices it doesn’t have special support for those devices and so you do lose some of the features. I also wish there was better support for IFTTT  so that I could create more interesting automation recipes. The tool does have their own”robots” that are pretty powerful but they are limited in what they can interact with and notify. Wink looks like they have great support but the couple times I called the lines were pretty backed up. The built-in video tutorials in the app are very straightforward and well done. Given all this I would consider the product more of a “beta” setup right now.IMG_0070

If you can pickup the Wink hub on a deal  give it a try. Compared to some solutions like the Phillips (and others) you don’t have to spend $150 just to get started. The robots make it easy to create simple automations and the supported switches, door triggers, etc. all are working pretty well for me.