Teardown
Emergency Button
I have recently tripped and fell at home, though luckily there were no injuries. But after it happened again, while walking through a parking lot and actually hurting myself, I realized that it’s time to start wearing a device to signal in case of an emergency. My loved ones were also concerned about my safety and were urging me to get one of the medical alert devices.
I bought a V.ALRT 400 emergency button for $30 from Amazon. Its has a software version HMHR00.01 and comes with an Android app, version 1.3.5-8b0a4ff8. After pairing it with my cell phone I could press a button to initiate a phone call or an SMS, to as many as three numbers from my contacts.
Unfortunately, this device is unstable: the Bluetooth connection with the phone is frequently lost. Several times the device went off by itself and initiated multiple calls and messages. It did not produce the sound I expected when activating a search for it from my phone. All things considered, the device was too unreliable and I stopped using it.
After this experience, I realized that I can’t rely on such a simplistic and unfinished product for such an important function. What if I am far from my phone and can’t pick up a call, or my contact is busy and does not accept the call or read the SMS. I started to look for a substantial product that comes with a service subscription. Not cheap, but in case of an emergency I wanted to be connected and talk to a person at the press of a button.
The number of offerings for the Personal Emergency Response Systems (PERS) is overwhelming. According to Reuters, global market for PERS was $5.6 billion in 2015 and expected to reach $8.61 billion by 2022, growing at a compound annual growth rate (CAGR) of 6.35%. Reviewing the services offered in my area, comparing prices and reading customers reviews taught me to pay attention to activation and cancelation fees, required contract, availability of customer service 24/7, device protection plan, fall detection features, GPS, landline vs. cell phone connection.
Looking for a quality device with a reliable customer service, I looked for recommendations from AARP, Consumer Reports, industry analysts and device comparisons. It turns out that some Medicare Advantage Plans (Medicare Part C) may cover PERS, including devices from four providers: LifeLine, Bay Alarm Medical, Mobil Help, LifeStation. Further, my Kaiser Permanente Advantage Plan teamed up with LifeStation to provide special offers for Kaiser Permanente members.
Such a strong recommendation prompted me to take a closer look at the company’s history and products. LifeStation is well-established and has been a reputable provider of medical alert systems for over 40 years. It sells directly to the elderly or to individuals equipping their parents. LifeStation also distributes through partnerships with healthcare providers, local government agencies and hospitals.
Their newest pendant product, Mobile GPS Premium (with WiFi) became my choice. The device and service are $29 per month (after a 25% discount through Kaiser). Device protection and automatic fall detection alerts are available for additional charge of $5.00 and $7.00 per month, respectively. There are no separate charges for the equipment, no initiation or cancelation fees, or a long-term contract and new customers have a 30-day money back guarantee.
The device costs $175 if I lose or damage it, so I added the protection plan, which can be canceled later. The Fall Detection technology is recent and may not detect every type of a fall, so I decided to wait and perhans add it later. This feature is particularly important for patients who suffer from epilepsy, seizures or fainting episodes, and are unable to press the help button.
Device description:
• Premium mobile GPS alert pendant comes with speaker and microphone built right into the device.
• Device can be used both in and out the home and there are no range restrictions. An emergency call connection can be made anywhere nationwide, if a good cellular phone connection can be established.
• Agent can use the transmitted GPS & WiFi information (WPS) to determine user’s location and send help. This is an upgrade over systems with just GPS tracking alone. The Wi-Fi positioning system (WPS) provides added data that enables monitoring specialists to even more accurately determine the location of the system user.
• Works with Amazon Alexa.
• Mobile GPS systems are waterproof.
• Fall detection feature can be added at additional charge. It can detect if the senior has fallen and then place an alarm call automatically.
• Caregiver Alerts system will send email alerts to people on the user’s emergency contact list when the user presses the button.
• LifeStation’s feature “Find My Loved One” allows user’s emergency contacts to send text message to an exclusive number that is linked to their loved one’s system. Caregiver Alert System will send back a text message with user’s location.
Customer Service description:
• LifeStation operates its own 24/7 monitoring center in-house in the US. The center adheres to both UL Listed and TMA (formerly CSAA) Five Diamond standards.
• LifeStation advises users to make monthly test calls by pressing their button.
• Email contacts can be added when setting up the user’s emergency contacts list, or anytime by calling LifeStation’s customer support. There is no additional cost for this service.
• The Caregiver Alerts feature is a supplement to LifeStation’s emergencies monitoring service. It does not replace the standard procedure to call on emergency contacts by phone and comes without additional charge.
I pressed the button to test my emergency system and the LifeStation’s support responded immediately. I told him that I am OK and was testing my new mobile GPS device. At the same time my emergency contact received the following email:
Subject: Acct# - Zone MA1 PERSONAL EMERGENCY (A)
Received Zone MA1 PERSONAL EMERGENCY (A) (-Event ID: 5cdeffc0e0d11 Listen-In Pending) on 05/17/2019 at 11:38 for
I also confirmed that when my emergency contact texted Find to an assigned number and they received a text message with my position and a link to Google Maps showing the location. So far, I am happy with my choice of this button.
Roomba Meets Alexa
Amazon Alexa can control the iRobot Roomba vacuum. iRobot Home mobile app goes through the steps to connect Roomba to Amazon Alexa:
- On Main Menu selected Smart Home
- Selected Amazon Alexa
- Follow the instructions to link the iRobot Home account to the Amazon Alexa account
In Amazon Alexa mobile app select Skills & Games from the Main Menu.
Enter string “iRobot Home” in the skill Search field. Alexa finds a new device easily and connects to its account. Once the skill is enabled and Alexa and iRobot accounts are linked I can use Alexa commands to start the vacuum, stop, pause, locate, check status and send it back.
In addition to the usual ways to control Roomba: buttons on top of the vacuum and the iRobot mobile app, with Amazon Alexa I can use voice commands, like:
- “Alexa, ask Roomba to start cleaning”
- “Alexa, ask Roomba to stop cleaning”
- “Alexa, ask Roomba to pause cleaning”
- “Alexa, ask Roomba where it is”
- “Alexa, tell Roomba I found it”
- “Alexa, ask Roomba what its status is”
- “Alexa, ask Roomba to go home”
Roomba 690
iRobot Roomba 690 vacuum, when it first came out two years ago, cost $400 from Amazon, tax included. Now it sells there for $280, making it a real bargain, compared to models 890 and 990. This reasonably priced model with Wi-Fi connectivity is also compatible with Amazon Alexa. For my small house with a low-level carpet, Roomba 690 seemed like a good choice.
The Roomba came with the Home Base charging station and a pair of Virtual Wall barriers. During initial charging of the Roomba’s battery I downloaded iRobot mobile app to my Samsung Note smartphone. In order to create an account and register my vacuum I needed my Roomba’s serial number. One removes the dust bin, turns the device over and here it, a 21-characters alphanumeric string on the white paper strip glued to the plastic body.
Default device name Roomba can be changed in the Settings.
Having logged into my account in the iRobot Home App, I selected Roomba device type and Set up a New Roomba. The mobile app guided me through the steps:
- Setup Home Base and charging vacuum battery
- Define WiFi name and password. [The app displays the name of the WiFi home network that the phone was connected to and asks for the password]
- Activate Roomba and connect it to the home network. [Press Home and Spot Clean buttons simultaneously. Roomba flashes WiFi icon and sounds a tone once ready for cleaning]
Initially playing with my new toy was a fun, but when it came to cleaning I was disappointed. There is a lot of preparation before one lets Roomba to do its work around the home: remove cables and area rugs, move chairs to make more room for it to get under the table. And still it gets stuck under a futon.
From the app here is the 2-year history of Roomba’s performance:Number of Cleaning Jobs: 40 jobs
Total Job Time: 3 hours 30 min
Dirt Detect Count: 19 events
Overall Roomba did not become my main cleaning device, and most of the time I use my old vacuum.
iRobot Roomba 880 or 980
A proud owner of the iRobot flagship product, the Roomba 980, I was looking for another unit for a different location. Pricing on the 980 is still rather stiff, at $900, so I decided to look downmarket. A couple of years before iRobot released the 900 series (980 and 960), they put out the 880/860. And you know what – the mechanicals on the underbelly are identical – brushes, trash bin, etc.
Buying the 980 was a part of my ongoing ‘research’ into home IoT. The thing connects to the Internet via WiFi and can be controlled via a smartphone App, from anywhere in the world. It does sound kinda stupid, and it is. I’ve used the App exactly once, when I first bought the unit. Now, if it had a turret with a camera, and I could drive it around remotely, that’d be way different…
And it should be a Mars rover and shoot Nerf balls at the cat. Dream on.
There are two things that I can see that make 980 better in meaningful ways. A Lithium battery does promise twice the charge (runtime). Though I usually run out of the trash bin capacity before running out of charge. Also, the Lithium battery last longer, over the years. Well, a replacement NiCd battery for the 880 is $78 from iRobot and an off-brand part sells for $25.
980 has some kinda camera thingy on top and better magic algo to cover a larger area faster and more evenly, or so they say. But I’ve seen it get stuck plenty of times, over an edge of a carpet, or tangled in wires, or wedged under furniture. Or not being able to get out of a maze formed by table and chair legs.
The way I use my 980 is one or two rooms at a time. The idea of having the entire (two-story) house cleaned in one go is a stretch. If it had three times the trash bin and could fly, it may be a viable proposition.What I do love most about having the 980 is that it slides under the beds. And the joy I feel when coming back to a house that’s cleaner than when I left. I call it R2-D9 (for the 900 series) and adore it as a pet.
But this time I’m buying an 880. The 980 price did not come down any, while the 880 sells on Amazon for $480. Over 40% cheaper, after factoring in a replacement off-brand battery in a couple of years, it’s a better deal, and it sucks just as much. And the 880 has a remote, which will actually be useful, to find the puppy, once again stuck under furniture, or to tell it to go to its bowl (charging station).
Cheap Qi Charger
Wireless charging is cool. Because anything wireless is cool. Next best thing to not having to do it at all.
So, people have tried to do wireless power for over a century. Think Tesla – the man, not the car. He wanted to send electricity across distances without any wires. At the moment we’d settle for charging the phone by putting it on a special pad, and avoiding three seconds of fiddling with plugging in the cable.
The Qi standard, of which we’ll talk further later, is built into the latest Google Nexus 6. And, there is a whole bunch of cheapo pads offered on eBay, one branded TechMatte. Having invested $11, I had a pleasure of taking it apart.
The top pops open without any tools, thanks! Here comes the Coil. Tesla would be happy, initially at least. The square piece of plastic that the coil is resting on is stuck onto the back of the case with two-sided tape, which one pry off to see the interesting part of the PCB.
The main ASIC is labeled GPMQ8005A, and it comes from a Shenzhen company Generalplus Technology. A QI Compliant Wireless Power Transmitter (no surprise there). I could not find an official quote on it, but on Alibaba there was an offer for $2.80. There are two TI (ON Semi) LM324 Quad Opamps, at $0.10 these days. Two Michrochip TC4427 MOSFETS, at $0.90, Alpha & Omega Semi AO4606 30V complementary MOSFET, say $0.20. Or maybe I got them all wrong. Will microscope them again at work.
On the back of the unit is says: Input 5V – 1.5A, Output 5V – 1A. In the context of a wireless charger, the Output labeling is wrong in so many ways.
Oh, the dang thing does not work. Have to take the phone out of the case. Finding the one spot on top of the pad where the green LED goes on is a game that grows old quickly. And, if you find it, by using an App that monitors charging you will discover that it does not charge worth a damn. Cannot even keep-up with the power consumption of the screen being on.
NiMH Chargers, Old and New(er)
Many flavors of Lithium batteries are popular now, Lithium-ion (Li-ion), and Lithium polymer (LiPo, or Li-poly). They do hold more charge (specific energy) than Nickel Metal Hydride (NiMH) ones, some almost twice as much, for the same weight. They can be recharged more times, and maybe even charge faster. You will find Lithium batteries in every cell phone and quadcopter.
But NiMH AA batteries are each sporting as much as 2500mAh at 1.2V (nominal). It does take 3-4 of them to get to the LiPo cell voltage of 3.6V. But the NiMH batteries hold that 1.2V level through just about the whole discharge cycle, which the Lithium ones do not. Most importantly, Lithium batteries are now viewed as a serious fire hazard, because they can get mighty hot, if not charged correctly. So hot, that some incidents were reported, of laptops catching fire. Now each Lithium battery cell and each device using them must have warning labels. There are rules about having them on planes or in postal parcels, as if they were some kind of a high explosive bio-weapon, which they are not. But, NiMH are considered safe, by default.
NiMH batteries are not as environmentally suspect, as the NiCd were, because of serious toxicity of Cadmium. And modern battery designs have no ‘history’. Remember, how once in a while we had to discharge NiCd batteries all the way in order to restore them, to make sure they did not ‘remember’ a smaller amount of charge? No more, with NiMH. One does have to charge NiMH with some care, so as not to overcharge them, as they can heat up a bunch, and also not to trickle charge them forever.
I found in my garage a 15-year-old Kodak NiHM charger, and also bought a Lenmar 8 Port Battery Charger over a year ago. Brands had shifted and diminished, but let’s find out what changed technologically in fifteen years. You will see that there are systematic differences, but also surprising similarities. There are four screws holding the Kodak unit together, tiny hex screws, and I was too lazy to look for a set of hex wrenches. A couple of small flat screwdrivers worked.
Lenmar went even further. There are six safety screws on the back, of a slightly unusual variety, with two slots on the sides. Not something common, like the star with a pin sticking out in the middle, which I do have bits for. Well, two different sizes of scissors did the job in the end.
The Kodak plugs straight into the wall outlet, but Lenmar has a walwart that brings out 12VDC. The beauty of such a setup is that you can have a walwart and a plug specific to every country and set of regulations, and the main circuit is the same, and only has low voltage. So everyone does this now.
But why would Lenmar use the funky screws, as inside there is no high voltage whatsoever. And these screws must have cost at least a dime a pound more than the common variety. Would those extremely pragmatic folks in Shenzhen ever do this on their own, or was this the one design contribution by their US counterparts?
The mechanicals of battery contacts and the utilitarian color and layout of the PCB top feel very similar between the two units. There is a bit of a difference in how actual electronics are accomplished. Besides the whole 110V AC issue that the Kodak has to contend with, they used a load of discrete components and a couple of ICs, TI LM324 quad Op Amps, which are a dime apiece these days.
Lenmar sports two Michrochip TC4427 MOSFETS, $0.90 each, though they must be getting them a whole lot cheaper. Also, one can see an Alpha & Omega Semi AO4606 30V complementary MOSFET, maybe $0.20.
So, now you know. The more things change, the more they stay the same.