I already owned a SodaStream system, but I figured I'd give this a try, since the price is right. A SodaStream canister is $30, so you can't go wrong getting a canister that is larger + a whole system for only $5 more.
It doesn't carbonate into a 1L or 0.5L bottle like the SodaStream. Instead, it's more like the single cup coffee makers. I've found that it seems to hold about 355ml of water (my glass holds exactly 355ml, the same size as a can of soda). Adjust the FSS button to control the size of the bubbles, press the carbonate button a few times (until you hear the buzz sound), then with your glass on the tray, press down on the lever to dispense the soda into the glass. You can either then add any syrups (or like I do, have them already in the glass before you pore in the carbonated water).
The perks are that it comes with a CO2 canister that is a standard paintball canister (but beverage grade, not like it makes much of a difference). You pop on an adapter that lets you plug the canister into the system. You can get the 20oz canister (larger than SodaStream's 14.5oz) refilled anywhere canisters are refilled. You can also plug in any standard paintball canister into the adapter that plugs into the system. Added bonus, the system also comes with an adapter to screw onto any SodaStream canister, so if you can't find any paintball refill locations, you can always just buy yourself a SodaStream canister to use with the system.
With the initial charge, I obtained 65L of carbonated beverage with a 20oz canister filled with 16oz of CO2. I've refilled the canister for $9 at a local homebrew store.
The unit comes with two kinds of tank threads. A green one that will fit SodaStream canisters and a grey one that fits Primo canisters.
The machine makes great carbonated beverage with the level of carbonation and bubble-size controlled by two machine mechanisms.
The hub is powered by a 2amp power brick. The power brick is fairly slim -- in a power bar, it would prevent another brick being plugged into the plugs next to it, but it does provide enough clearing to allow someone to plug a power cable into adjacent plugs. The hub will provide enough power (1amp) to power the Pi. Unlike other high-powered USB hubs that I have tried, the hub will provide greater than 0.5amp to device connected to it even though there is no host connected to it. This is critical. A lot of other hubs I have tried, they will provide high-power to a USB device connected to the hub only if there is an established host connection to the hub. Therefore, if you try to connect a Pi to the hub, it is not able to provide enough power to the Pi to start it up because there is no host connected to the hub. The Pi needs to be powered up before it will establish a host connection with the hub.
With the Monoprice 7-port USB hub, the hub will provide enough power the usb connections to power the Pi up even before the host connection is established. This is witnessed by a red light on the hub, which indicates it is powered on. When the Pi itself is powered on and started, blue lights will turn on the hub to indicate connections of those devices to the host have been established.
The hub also prevents backpowering over the USB host connect. This allow for a switch to actually work. Without this ability, the power switch would be futile as the Pi would become powered on automatically via the host connection between the Pi and hub when the hub gets powered on.
The hub will provide 5 USB side connections and 2 USB top connections.
The hub can be disassembled. The plastic case is easily removed.
The board could be integrated in your Raspberry Pi case design, as I have in my headless Pi server.
A power switch was omitted in the design of the Raspberry Pi to keep costs down. There was no easy interface provided to add one either, but there are many different options. I had previously tackled the original topic in a previous post, comparing a few options, including building your circuit.
Challenge: The Raspberry Pi always remains powered-on as long as there is power coming in on the micro-USB power line. A shutdown/halt/poweroff command will shutdown the OS and leave the system in a powered on but idle state. The power consumption would be unchanged between idle and active on the Raspberry Pi. Further, to turn the system back on, the USB cable needs to be unplugged or the power supply needs to be unplugged (reset).
Ideally we need....
something that powers the raspberry pi off when it is shutdown (power consumption becomes negligible / < 0.5 W) [POWER OFF]
something that can trigger a clean software shutdown [CLEAN SHUTDOWN]
Over the past few months since the original topic / post, I've covered the following options:
A power switch was omitted in the design of the Raspberry Pi to keep costs down. There was no easy interface provided to add one either, but there are many different options. I had previously tackled the original topic in a previous post, comparing a few options, including building your circuit.
At its core, it promises the same functionality has the other board solutions that intercept the micro USB power connector on the Raspberry Pi, which is to control the power on/off state of the Pi through a switch and through software. But instead of intercepting the power flow through the micro USB power connector, it controls the power through the GPIO. Instead of connecting your power to the micro USB power connector on the Raspberry Pi, you connect it to this board. You then either toggle the power state by pressing the black button on the top, or better, you can use a IR remote to toggle the power.
And there lies one of the key differentiators. For application use-cases such as a media player where you need an IR receiver, this board accomplishes that purpose as well. I discussed how you could construct your own IR receiver setup on the GPIO in a previous post, and also talked about HDMI CEC in the same post, but one of the issues that remains in either the case of adding an IR receiver or using your TV's built in HDMI CEC support (if it has it), is that you can't power on or off your Raspberry Pi using either your Pi or TV remote. Your solution options were either to always leave the Raspberry Pi on, have it automatically turn on when your TV is on (either by a power bar or plugged into the USB service port on your TV) or manually turn it on using a hardware switch or plug when you want to use your Pi.
I don't always watch all my media content through the Raspberry Pi (such as when I play video games, watch TV channels etc), so I resorted to using the illuminated switch bundled with my IR receiver that allowed me to keep my Raspberry Pi off, when not in use, and turn it on manually by pressing the switch when I wanted to watch some Pi content. There were a couple times I wanted to be able to use my Logitech Harmony remote to turn on the Pi. One of the benefits of this switch implementation is that it will use the IR remote's power button to toggle the power to the Pi. The IR receiver on the board will also work like any standard /dev/lirc device, meaning that it could replace the IR receiver I had setup on my Pi -- that it was completely compatible with XBMC.
The switch and IR receiver is contained on a single logic board. It has a connector port that plugs directly into the GPIO. This wasn't a concern for me, since on my XBMC Raspberry Pi units, I only use the GPIO for two purposes -- hooking up a power switch and hooking up a IR receiver. The direct connection to the GPIO eliminated some wiring that I needed to contend with with the IR receiver and previous power switch. The board also came with a screw with some watches and nuts so that it could be securely mounted directly onto the mount hole on the Raspberry Pi. The first releases of the Raspberry Pis (the model B 256MB "rev 1") don't have this mount point but the board is still usable without the mount..
I decided to integrate the board with my model B bedroom TV Raspberry Pi case. I had reviewed the lego case I had constructed for that project in a previous post. I had still not integrated any power switch into this unit, so I was eager.
To keep inline with the pros and cons list I provided for the other switch mechanisms, here are the lists:
Pros:
very small
may need some modification to your raspberry pi case, but otherwise fits within the existing case (doesn't extend out from the board's footprint)
addresses the CLEAN SHUTDOWN and POWER OFF requirements fully
I took apart my case's right wall to accommodate the new higher-oriented micro USB port. I would be revamping the case completely now that I no longer needed to snake my IR receiver around to an opening on the front of the unit, I could now also drop down the height of the case due to the same reason and I would need to accommodate the hardware button to accommodate the manual switch.
The instructions provided were very simple. After I applied the screw and plugged in the board, I connected the micro USB power to the board's port. Immediately I saw the built in power LED flash green and red momentarily to indicate the unit had power. I then press and held the power switch button down for 15 seconds, at which time the LED blinked between red and green continuously, indicating that it was ready to read the IR remote command for the power button. I used the Logitech Harmony power button that had been setup for the WD TV remote profile that I had setup previously on the unit's previous IR receiver. It really doesn't even have to be a power button -- it can be any unused button. The blinking stopped and I could then press that button to turn on the unit.
When the IR power-assigned-button is pressed, the board's onboard LED starts blinking green, while the Raspberry Pi turns on. Everything booted up as it would regularly. I didn't have to make any changes to my lircd.conf profile. I started using the unit as I normally would.
The blinking -- which is more of a "pulsing" -- for up-to-one minute on startup and shutdown give an indication that the command was received and also indicates that the unit won't respond to subsequent power on/off requests from IR during that period. This prevents accidentally sending a second power on/off command to the unit while it works on the initial request. It also prevents "repeating" if the IR remote sends the same commands multiple times. .
If you are implementing this as a new IR implementation (not replacing an existing setup), you'd need to setup a remote and lircd.conf. I discussed how to do this in a previous post.
I had no problem using the onboard IR receiver with all my Harmony remote commands or with the WD TV remote that I keep around as a backup to control the unit when my Harmony remote is lost in the room-somewhere or is charging.
To power off, I pressed the power button again. The board passes on all the IR signals received to the Raspberry Pi, including the one assigned to the power button, but it will start triggering a shutdown when the power-assigned button command is received. It does this by the irswitch.sh script that is installed as part of the setup. It closely resembles the safe shutdown script (switch.sh) that I discussed using with the other power switches. The board's LED flashes red while the board shuts down the Pi. It continues to monitor the Raspberry Pi's shutdown for up to a minute. When the Pi is safely complete it's shutdown, the power is cut off (so the Pi becomes powered off), and the onboard LED turns off. You can then use either the manual power button on the board or again the IR remote's power-assigned button to turn the Raspberry Pi back on.
The onboard LED proved to be a great asset to this power switch. I no longer had to position the front-face position in my original lego case:
I retweaked the right-side of the case to become the new front-end of the unit.
The before:
The after:
I placed a white window block where the onboard LED is positioned, that gives the unit a nice glow when lit. I placed an inset blue window piece for IR window. The IR range provided by the window is adequate enough to get at least a 45 degree angle using the remote. I moved up the blocks for the micro USB power port to line up with the new port. I also added some support around the SD card as it was previously hanging out of the system. It is now protected from being hit (and damaging the SD card port).
A closer view:
I revamped the top of the case to integrate the power button as well:
I review all the changes I made to my Raspberry Pi lego case for this board in this follow-on post. In general, it is very easy to integrate the board into most cases as it doesn't change the footprint size of the Raspberry Pi. The only customizations that are needed are:
hole on the top for the manual power switch,
relocation of micro USB power source in a higher position and
Recently I purchased a Belkin WeMo Switch. The switch makes a single electrical outlet become online by putting it on Wifi. You can then use an iOS 6+ or Android 4+ app to toggle on/off the switch. I didn't really see to much benefit of the app, as I already use Connected by TCP to control lighting around the home, providing me the ability to dim lights as well.
Of bigger importance to me was the IFTTT capability of the switch. IFTTT, which stands for If This Then That, is an online service that lets you create recipes that can toggle the WeMo. Because IFTTT is enabled for many other online services, you can tie the toggle on/off of the WeMo to other events, such as a gtalk or email message. You could toggle the WeMo by the sending of a message to a IFTTT bot that contains a hash-tag that you assign to toggle your WeMo. This makes it really easy to control a switch in your home from any device, not just your phone. Likewise, IFTTT also has scheduled events as an ingredient, so you could use it to control what times your WeMo is on and off for.
There is a newer version, called Belkin WeMo Insight switch that has a much smaller footprint and also monitors and reports the power consumption of the device plugged in. The Insight switch is about $10 more expensive. It wasn't carried in any stores in Canada at the time of purchase (Home Depot, Canadian Tire, Future Shop / Best Buy, Amazon)
My particular interest in the Belkin WeMo Switch was as a Raspberry Pi power switch. It makes a powerful switch for the following purposes:
Serves purposes where something similar to as WOL (Wake on LAN) is needed. I often use WOL on my systems, so remotely, I can connect to my home network and turn on computers as I need them, but issuing a WOL packet from the router to the PC. For the Raspberry Pi, the Pi is always on as long as it has power supplied to it, therefore the USB-based ethernet switch doesn't feature the ability to turn the system on by WOL. To do so, you would need to design and build your own power switch that could intercept the micro USB powered source and also reimplement the ethernet port by intercepting ethernet traffic capturing WOL packets and then controlling the power based on that. There exists no ready-made logic board, so creating and implementing one would be impractical (and expensive). With the WeMo, you can the toggle on power command straight to the switch, and anything connected to it will turn on.
Scheduled on/off time. If you need the system to be powered on during a certain time of the day (scheduled crontab job), you can schedule the toggle on of the WeMo by a scheduler on IFTTT. Likewise, you can toggle it off at a different time. Therefore, a scheduled crontab entry, I schedule my WeMo to be triggered on 5 minutes before the crontab entry is to run, and likewise, I schedule the WeMo to be triggered off 5 minutes after a matching crontab entry on the Raspberry Pi is scheduled to shutdown the system. Further, because there are three kinds of states you can use (toggle on, toggle off, toggle power state), if you toggle on the WeMo at a scheduled time, if it is already on, it won't be affected (as in, it won't be turned off by accident, unless you use the toggle power state as opposed to toggle on).
Control your USB powered hub. In my particular application, I'm powering the Pi using a power switch, which is plugged into a hub, where my USB devices are also plugged in (such as hard drive). So, although I can schedule a shutdown on crontab which actually powers off the Pi with the addon power switch, the USB devices such as hard drive, remain powered on. With the WeMo, I'm actually powering on/off the USB hub, so it would include automatically powering on/off the Pi itself.
Remote hard-reset. If (really more of a case of when) the Raspberry Pi becomes frozen or unresponsive where I'm not able to connect to it remotely to perform a reboot command, The WeMo allows me to either use my phone or IFTTT to toggle the power off/on.
Some conditions or other notes:
If you are strictly power off using the WeMo, you could corrupt the SD card or USB-based hard drive filesystem if you practice the habit of poweroff by cutting the power as opposed to safely shutting down prior with either a poweroff or shutdown now -h command. In actuality, you could use a third party, such as Linux-capable router (which is my case), where if I need to perform a safe power down, I have the router issue a shutdown now -h over ssh to the Raspberry Pi, and then issue a #pi-off over email to IFTTT a minute later to actually power off the device.
If your Raspberry Pi starts up requiring root login to correct a disk issue, then you have no way around the issue other than to interact with the Raspberry Pi locally. There is probably some way around this, some setting that lets you disable disk checks on startup, thus avoiding the prompt at startup for a root admin to log on to perform maintenance or CTRL-D to continue. These prompts are not just tied to real disk corruption. If I take my USB hard drive offline to sync it with another hard drive using another PC, if I write changes to it's supernode in the process, the next time I boot up on the Rasbperry Pi, it'll see the supernode has a timestamp newer than the system clock and thus refused to boot until a root user takes a course of action. This nuance is for the fact the Raspberry Pi lacks a realtime clock, so on bootup, the present time will be the time at which the system was last on (stored to the SD card), so the fact the hard disk was updated or had changes to it with timestamps that are newer, it detects this as possible corruption-based issue. Only after the system is booted up and on the network will the NTP set the time on the Pi to the current one.
You need an iOS 6+ or Android 4+ device even if you intend to only control the WeMo via IFTTT. The WeMO needs to be setup via the phone app.
The initial setup of the WeMo was fairly simple. From what I read, the Android version of the app was created more recently and just came out of beta, and tends to have more bugs in it then the iOS version. Therefore, I decided to dig my iPhone 3GS out of retirement for setting up this device, over the Android. I plugged it in, then on my iPhone 3GS, I downloaded the WeMo app from the appstore. As instructed by the app, you then need to change your Wifi access point on the phone to the one broadcasting from the WeMo. Then at this point, the app will ask about the network setup of the WeMo, for which you provide the network key. This was fairly simple. But I did read online that a lot of users had problems at this point as their WeMo didn't accept network passwords with special characters (non-alphanumeric) such as spaces. I'm not sure if this is resolved with a newer firmware, but if you have a network that uses one, you're out of luck with a out-of-box device until you get it onto a network it will accept.
As part of the setup, you provide it a name for the switch (assuming you may one day have multiples). In my case, I just called it Raspberry Pi Server. You can also assign it a user-created PNG graphic to depict the device image in the app.
After I got the device setup, I was prompted by the app to update the firmware on the WeMo as there was a newer one available. This is where I began to quickly learn how buggy the firmware and app are. I accepted the app to let the WeMo download the firmware. At this point it instructs you that you can close the app, that the WeMo is downloading the firmware direct (indicated by flashing blue light) and will take about 10 mins to complete, at which time the WeMo will reboot and be ready for use. I left the app open just the same, and went off to get a coffee. When I got back I saw the WeMo was done the firmware upgrade, but instead of a steady blue light (indicating on) or no light at all (indicating off), I was presented with a blinking amber light. It would seem this may have multiple meanings, but the initial one I found was that the device was not able to conenct to wifi or is still trying. Checked the router and it confirmed the WeMo was not connected, having been connected and assigned an IP prior (since it had finished setup and had downloaded the new firmware). I checked the phone app and it indicated the device was "firmware upgrading". Unplugging it and plugging it back in proved futile. I quickly learned of the restore procedure to try to trigger the device to restore to factory state. So, went through the initial setup again, assigning the device a new name, giving it the network password etc. This time at the completion of the setup, instead of letting me see the state of the switch in the app, it said the device was "firmware upgrading". I had used a different name the second time, and it was the second named switch that it was in belief was firmware upgrading, whereas looking at the device, no said activity was underway. Closed the app and started it again, and it was able to see the on/off state of the app correctly.
So, as you can see, both the app and the WeMo firmware are buggy, and I'll be more apprehensive on updating the firmware in the future. Because it was freshly out of the box, I tend to take on more risky behaviour such as updating firmwares since I can just turn around and head back to the store to return the bricked device. Had I updated in weeks or months following, I'd be at the mercy of the manufacturer RMA procedure.
Setup was easier for IFTTT. Activating the WeMo channel in IFTTT just involved providing it the unique identifier number that the phone app provided so IFTTT could locate and use the WeMo. I didn't have to open any firewall ports, etc. Either the WeMo is pulling the requests or it is opening a port on the firewall itself. I'll look into the details someday. I'm interested in seeing what the packets look like going between IFTTT and the WeMo.
the latency is minimal; within 1-2 seconds of triggering a power toggle on the app or in IFTTT, the WeMo is toggled
this speaks more to IFTTT itself, but the time between emailed hash-tag emails to invoke the WeMo are processed usually around 5 seconds after the email request departs
survives power failures with settings preserved
Cons:
pricey (around $40 - $50)
firmware update process is buggy
requires the phone app for at least the initial setup
users report problems with network passwords with non alphanumeric characters
almost guaranteed to have problems with enterprise networks (such as ones that requires LEAP etc)
no surge protection; designed to fit outlets, not power-bar friendly, but it contains no surge protection and the huge footprint of the device causes hindrance plugging it into outlet surge protectors
unless your outlet plug sits flush with the surrounding wall, or extends out a bit, the overhanging of the switch will cause problems
causes havoc with powerbars; the footing is larger than power bricks, so even when a powerbar (or in my case APC UPS) has a "power brick outlet" to eliminate impact of a power brick on adjacent outlets, the footing still causes problems, barely allowing a two prong cable to clear (see picture of my setup)
[There is a newer version, called Belkin WeMo Insight switch that has a much smaller footprint and also monitors and reports the power consumption of the device plugged in. The Insight switch is about $10 more expensive.]
network security issue; network details of the device are not transparent which is probably intentional to obscure security vulnerabilities
it is essentially an embedded computer, so when you first plug it in (or turn a power bar on) it takes about 30-45 seconds for it to boot up (indicated by blue blinking LED) and another 30 seconds for the device to find and connect to the network (indicated by amber blinking LED)
consumes power (using a kill-a-watt reader, the device registers at 2 watts when idle and around 2.5 watts at bootup) -- the Raspberry Pi model B rev2 consumes about 2.5 watts, and the Raspberry Pi model A consumes about a constant 1.5 watts, so the WeMo consumes the same or more power than the Raspberry Pi.
Pros as a Raspberry Pi switch:
control the power switch remotely
lets you perform hard reboots remotely
control the power to the USB hub and all your Pi devices with a single switch
control the power to your Raspberry Pi using IFTTT, including implementing scheduled activities, activities based on other events
home automation necessity -- use in conjunction with motion sensors tied with IFTTT to aid in setting up home automation; the WeMo switch is only one product available in the WeMo Home Automation category.
Cons as a Raspberry Pi switch:
no software shutdown support (need to software shutdown prior to avoid corruption of filesystem)
