John Galea's Blog

My blog on Gadgets and the like

Mengk bluetooth headset Eurobird HM2000

I was looking for an inexpensive bluetooth headset to replace my iKross BT19 which is no longer available. I saw this one and decided to try it.

Size and weight are good, buttons are very minimalistic, so much so as to make this device super clumsy to use. There is a fwd/rwd button that if you push and hold act as the volume up and down. Seems to me one would use volume more so why it isn’t the one that does not require holding is beyond me. The button on the front turns the unit on, and changes between streaming bluetooth and FM and powering off. Getting the front button right is all about pushing and holding just the right amount of time. Too long and you just powered it off. It’s irritating

The 3.5mm audio plug is NOT compatible with 4 pin stereo/mic headsets, only stereo ones. Sound quality is really not great even in blutooth streaming.

FM radio is reasonable well done and includes simple to use audio prompts in english.

The device can not be used while charging so it is useless as a permanent bridge.

In the end I returned this device due to poor audio quality, the lack of support for a 4 pin audio plug and maddening usability.


May 27, 2017 Posted by | Uncategorized | Leave a comment

Sony Ericsson MW600 bluetooth headset review

When I mountain bike I love listening to music. But having a wire to the phone in your pocket is a pain (sometimes literally). So I like to use a bluetooth headset. It also makes it possible to take a call if there was something urgent. In the past I have owned a Samsung HS3000 as well as an iKross BT19, both of which I liked and used a lot, but neither are still available and both are either broken or lost. I particularly liked the big buttons on the iKross for use with gloves while riding … Finding a replacement has been surprisingly challenging. One of the problems I have is that for whatever reason in ear headphones, never stay in place on me.

So I thought I’d try this one. First off, it’s worth noting that this device is no longer sold by Sony Ericsson so if you want one buy it while you can. There are some still on Amazon.

First off the headphone connector is a standard 3.5mm, and is compatible with both stereo (3 pin) and stereo with a mic (4 pin) headphones. This comes in handy. Sound wise this is one of the best to date with the right headphones. The included ones are fine, a little lacking in base and as usual they don’t stay in my ears.

The unit is capable of pairing with two devices simultaneously, so say a phone and tablet.

Size wise, it’s about the size of a AA battery and light. Buttons are a power and micro USB for charging on the end, fwd/rwd/play-pause on the bottom and a bizarre slider for volume on the top. If there is a weakness or annoying thing about this device it’s the volume. You slide your finger along it and a visual slider comes up on the display and you slide up or down. It’s hokey at best. I have no idea what they were thinking of when they decided to do this. And it is impossible with any kind of gloves on. I could go on about how stupid this is … On the front is a single easy to use button that allows you to receive and end incoming calls. Double click and up comes SIRI! Perfect

There is an OLED display on the unit and it works super well … kind of. The display will show you the FM station your on (more about FM in a bit), the song playing when on bluetooth streaming, shows the bluetooth connection and battery state, time, and who is calling . The display is comprehensive in what it displays … but … and there is always a but, the OLED display is completely unreadable in any amount of sunlight. Really bad. And there is no way to tell what radio station your listening to without the display. There are no audio prompt whatsoever on this device. An over sight IMHO.

Sadly the device can not be used while charging so you could not use this device as a permanent bluetooth receiver. Dumb and limiting.

The clip that holds it to your clothes is quite soft and the spring is not all that robust. I can only hope it will last.

Battery life is claimed to be talk time up to 11 hours, standby time up to 500 hours, stream time up to 8 hours 30 mins, FM radio playing time up to 11 hours and charging time approximately 2 hours. Like most devices in this category there is no accurate way to tell the current battery status. The display shows the battery status but it’s too small to be able to discern much of anything.

There is an FM radio on this device and it works reasonable well and supports RDS so you get the radio stations call sign and the song playing. Impressive! Press and hold fwd/rwd and it will scan for the next radio station it finds. Reception seemed ok.

This headset can be paired to two devices at the same time, and from the headset menu you can choose which one you want to listen to and control. It’s not as seamless as the HS3000 but at least it does work.

If there was anything I wished most for, it would be an app that would run on the phone and allow you to control and see what’s going on with the headset. Now to be honest, I have NEVER seen anyone do this, but one can dream.

This headset does not support the Apple ability to display the headset’s battery status.

All in all I am pretty happy with this headset. The biggest niggle would be the silly volume control. But given how good everything else is on this headset, I guess its not so bad. But why they felt it necessary to reinvent the wheel is beyond me. There does seem to be a slightly newer model Sony SBH54.

May 24, 2017 Posted by | Uncategorized | Leave a comment

How to use HRV

I last did a post about HRV, an introduction of sorts, I’ve learned a little more so I thought it was time for another post on the subject. HRV or heart rate variability is a way to tell what shape your body is mentally and physically. It can be used to judge when it’s time to go all out on the next workout and when it’s time for a light stroll. It can be used to measure physical and mental stress as well. Some devices such as Garmin Vivosmart 3 and Lifetrak Zoom HRV are attempting to do all day HRV measurements. How good or accurate (or even useful) these are is very much a TBD. I am skeptical.

HRV is a measure of the variance of time between heart beats. A healthy and well rested system can react quickly to needs of the body. There is good HRV and bad HRV but the reality is there is a range. Too high is bad and an indication of one issue, too low is bad and an indication of another issue. Now I am not a Dr, I am an engineer :). So I will make no attempt to explain the physiology of any of this. What I will try and do is discuss what you can glean from HRV and how to use it.

First up is tools, you will need a highly accurate heart rate monitor. For now that seems to be chest straps. I have a Wahoo TICKR and a Polar H7 both of which seem to do just fine with HRV and give consistent readings. Next up is an app on your phone. The last time around I put a few through their paces and decided on EliteHRV. It is simple to use, easy to understand and works well. If there is anything I wish for, is a portal, where I could see the data offline, on something other than my little phone screen. Oddly enough the app does send the data up to the cloud, I guess for their use.

Taking a measurement is pretty simple, get your chest strap, wet it (most chest straps have to be wet to be accurate), sit still start the app and wait two minutes. Two minutes seems to be about the right amount of time to get a reliable accurate consistent HRV reading. The more still you are the better the measurement. For the first couple of days you will get nothing out of the app while it figures out your baseline, normal, state. Once done you are now ready to start getting some meaningful data out of the app.

I am not going to try and discuss HRV during an activity, at this point I have not figured out what it means, or even how accurate or useful it might be,

So let’s get started. After taking measurements for a bit it was time to see what shape I was in before a ride. So I took the measurement, and as you can see I am in the green and good to go! The intra chart shows a pretty stable reading.

The reading isn’t right in the middle of perfection but it’s well within the range of what it considers good for me. So off I go on a ride. I rode for 2.5 hours, and then retook my measurement. Sure enough it shows that my body has been under some considerable exertion for me). My HRV had dropped from 59 in the morning to 36 after the ride. The only thing missing would have been a nice simple dial again. I have no idea why they only do this for morning readings.

So the next morning I measure my HRV again. Here you see I have recovered from 36 back up to 51, but it’s still in the yellow meaning if I were to go out an hard exercise it might be a bad idea. I would be at risk of performing badly or even injuring myself pulling muscles and the like.

By the next day you can see my HRV had recovered back up to 58 (now two mornings, and roughly 36 hours after my ride). As an interesting note, my Garmin Fenix 3 gives you a guess at what it thinks is your time to recover from your workout, and it guessed 29 hours so in the same range.

Now to see the affect of things other than exercise, I had a really bad night of sleep. And low and behold my HRV, down to 51, reflected it and showed a deccrease and the fact that I would not be in a good place to do a hard workout, something I felt anyway.

Here’s another pre exercise HRV, then a post exercise and then the next morning. This time it dropped from 54 to 43. This was an easier ride 688 calories Vs 1244 (according to my Fenix 3) from the previous example and as you can see my HRV dropped only 11 this time Vs 23. And as you can see it took less time to recover from my exercise, the next morning I would have been good to go again for another workout (albeit just barely).

And for completeness here is an almost perfect HRV after a good long nights rest. Right smack in the middle of the good range!

This last image is a way of seeing it all in one. You can see here it’s about a range. Too high is bad, too low is bad. It’s about distance from center of your normal. You get the best readings and accuracy when you take your HRV regularly.

May 19, 2017 Posted by | Uncategorized | Leave a comment

Leg based heart rate monitors

I’m always looking around for new ways to track my heart rate. In my mind the heart rate can tell a lot about you and your day. Warning … This post is going to be a bit of a ramble. A couple of new products have come on the market and I have been thinking of splurging on. The new Garmin Vivosmart 3 looks interesting and includes true all day heart rate monitoring. This allows you to get a couple interesting tid bits of information including your resting heart rate and your HRV. HRV (heart rate variability) is a measure of how stressed/tired/exhausted you may be and can be used to guide you in when and how long/hard you ought to work out. A quick read on DC Rainmakers web site reveals, as expected, wrist based heart rate monitoring for cycling is not practical. In Ray’s words “In case it’s not overwhelmingly obvious above (the yellow line): It sucked.  Badly.” On the positive side it would give me more data in the Garmin connect world, and would land all my data including sleep/tracking all in one place, the holy grail. So if I bought this one, I wouldn’t be using it on my rides.

Another gadget that caught my eye and what triggered this post is the Lifetrak Zoom HRV. This is again a wrist based all day heart rate monitor that also provides HRV (thus the name Captain Obvious :)). One of the unique things they did was provide an optional arm/leg band so you can move the sensor to somewhere it might get more accurate data during workouts (ie off the wrist). They claim they can get accurate data from multiple places on the body. So it got me thinking, I wonder if it’s actually possible to get an accurate heart rate from the leg? The lifetrak even recommends using it on the leg for cycling in which case it will also get cadence (rate of rotation of the peddles). Hmmmm.

And thus we have the experiment. So first off, I do not own a LifeTrak Zoom HRV, I do however own a Scosche rhythm + that can be worn on the leg. I’ve never seen anything talking about whether you can or can not do this so …. I wore the sensor on the leg above the calf, below the knee. This insured it wouldn’t fall off when cycling.

One of the first things you have to ask yourself is what are you trying to do with the heart rate? If you are trying to use it to keep your workout in zones then accurate data is a MUST. If all you want is an accurate calorie count then accuracy of the data at a given point is less important, average are all that really matter.

First off lets have a look at simple sedentary measurement. Sitting around not doing much. In this case the data actually looks quite promising. Both the point accuracy and average look good. For this comparison I used a polar h7 chest strap.

Expecting more than a 10% accuracy is unrealistic in this market segment IMHO, however having a variance of 8 bpm is getting up there as impractical for use for heart rate zone management.

Now let’s have a look at quick stair climb. This time the leg will actually be doing something. This time around it looks bad. There’s a short period of time where it’s just an act of fiction. Then a period of time where it lags (somewhat expected) and lastly it seems to somehow catch up.

Again it did reasonably ok from averages point of view, but bad for point comparisons.

Now I went on a short walk 20 mins. In this case for the most part the data tracked reasonably well, although there’s some noticeable lag in the heart rate being detected on the leg, and then something bizarre on the end of the graph.

And last but not least we get to my real use case, cycling. Visually comparing the data during the ride the leg based heart rate monitor was REALLY BAD. Like unusable, an utter act of fiction. If you were using it to guide you in zones you would be completely off. Average wise, shockingly it’s not so bad. I can only imagine the pounding of mountain biking could make this even worse.

I had another thought … What about the ankle, would it be any better? Again the scosche is on the ankle and the tickr is a chest strap. As you can see, other than an odd drop out for a period of time it was not totally out to lunch. Now that said, again, it would not be accurate enough to use for keeping you in zones. There were definitely times when I could see 10 or BPM off. Enough to effect what zone your in. And again, average wise it was not half bad.

So what does all this mean? First up for cycling, the Rhythm can not be worn on the leg for accurate heart rate data. I would also be skeptical that when worn on the leg that the Lifetrak Zoom HRV could be considered accurate enough for cycling. Now I admit to making a HUGE leap having done this test using a different monitor, but I have seen comments around the web that have also indicated that the Zoom on the legs accuracy on heart rate is BAD.

I asked Scosche about using the sensor on the leg, here is what they said: “Greetings John we have had customer use our monitor on their leg. As far as testing, no real testing has been performed on the leg application only the forearm.”

May 11, 2017 Posted by | Uncategorized | Leave a comment