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Cardio Grapher Beta

Posted on December 15, 2011 by Dave Comment
As hinted at in my previous post, I’ve been working on an Android application in my spare time for the last month or so.

As a result of me no longer being a student I can no longer go cycling so easily during the middle of the day when there is daylight and the roads are quieter. When winter has passed so I don’t end up cycling back in the dark (multiply the distance by the number of working days the journey would be in the dark for and take into account the fact it would be at rush hour and on busy roads and that’s quite a lot of risk to accumulate) I’ll get around this by cycling to and from work (I did a few times before winter set in). But for now I’ve bought a turbo trainer for my bike and have it set it up in my flat.

Now, necessity is the mother of invention and as with many of the things I’ve built this was the case here; when cycling out on roads I’ve used Google My Tracks a lot (and even added a small feature at one point), but when inside it becomes a lot less useful – obviously all distance and speed data (derived from the GPS) become meaningless. Now, I could setup a standard magnet based cycle computer on the rear wheel, but even then the data are not so meaningful – knowing that you’re doing e.g. 20 mph when stationary doesn’t really give you any idea how you’d be doing out on roads. So heart rate really does become the metric of real interest.

Of course there are numerous applications out there already that will connect to the Zephyr HxM (the Bluetooth heart rate monitoring strap I bought) – for example, My Tracks itself has support for a wide range of sensors – but the majority of them share the problem that displaying heart rate is only one the things they do and as such little emphasis is placed on doing things with that metric other than graphing it and giving the current value.

Enter Cardio Grapher: While it doesn’t yet do that much more than the existing solutions, my intention with it (as you may guess from the name) is for it to solely work with heart rate data. As such, I intend over time to explore a number of ideas for metrics that can be used to gauge the quality of a workout and to track progress.

Today I’ve released version 1.0, which I consider to be beta quality. The features:
- Live graphs of your heart rate over the last 1, 10 and 120 minutes.
- User specific heart rate training zones, helping you get the most you can from your training (based on formulae from http://www.machinehead-software.co.uk/bike/heart_rate/heart_rate_calculator.html).
- Audio alerts when entering and exiting training zones.
- Can be set to keep the phone’s screen on when in use.
- Can be set to automatically switch the phone’s Bluetooth adapter off and on again when connecting to the HxM times out (this is a work around for a bug in the Bluetooth implementation on some phones).
- Reports the remaining battery charge level of the HxM.
View it on the Android market here: https://market.android.com/details?id=net.cardiographer

Screenshots:
This entry was posted in Cycling, Hardware, Software and tagged aerobics, bluetooth, cardio, cardio grapher, cycling, graph, heart rate, hxm, spinning, training, turbo trainer, zephyr. Bookmark the permalink.

Easter Term 2011 – Part 1

Posted on May 29, 2011 by Dave Comment

405.23 miles so far:

Route	Date	Comments	Cateye	MyTracks	CL Weather
North Cambridgeshire (Variant) 2	23/04/11		Time: 1:28:08 Dst: 26.91m Av: 18.3mph Mx: 26.9mph	It failed to record many parts	27.80°C peak
Cambridge Semi Orbital 43	25/04/11		Time: 1:17:12 Dst: 22.88m Av: 17.7mph Mx: 25.2mph	Av 28.8km/h	~10°C
North Cambridgeshire (Variant) 3	27/04/11	A new personal best! I'm going to drop the "Variant" from this and make it the normal route. It's longer than semi orbital and avoids the traffic lights and roundabouts of Cambridge itself.	Time: 1:24:43 Dst: 26.81m Av: 18.7mph Mx: 27.1mph	Av 30.53km/h	~12°C
North Cambridgeshire 4	28/04/11		Time: 1:26:43 Dst: 26.81m Av: 18.5mph Mx: 25.1mph	Av 29.82km/h Route: View North Cambridgeshire 4 in a larger map	~12°C
North Cambridgeshire 5	29/04/11		Time: 1:28:08 Dst: 26.79m Av: 18.2mph Mx: 25.7mph	Av 29.6km/h	~18°C
North Cambridgeshire (Variant) 6	30/04/11	I went the longer way back, through Landbeach, Waterbeach, Horningsea and Fen Ditton. The wind was fierce!	Time: 1:51:33 Dst: 32.29m Av: 17.3mph Mx: 31.1mph	Av 27.96km/h	~18°C
North Cambridgeshire 7	06/05/11	Another personal best! There's quite a gap between this ride and the last: I did another dissertation sprint, this time for the second draft.	Time: 1:25:26 Dst: 26.82m Av: 18.8mph Mx: 28.7mph	Av 31.92km/h	~22°C
North Cambridgeshire 8	07/05/11		Time: 1:26:33 Dst: 26.84m Av: 18.6mph Mx: 31.0mph	Av 26.89km/h (it failed to record half of the ride)	~24°C (it rained in the morning but had cleared up by the time I left)
Cambridge Orbital 5 (slight deviation from the normal orbital; the rail crossing in Great Shelford was closed so I had to take a diversion)	08/05/11	I made a minor saddle adjustment (brought it forward and down) and it seems to have almost solved the back pain I was having. Now I just need to upgrade the saddle itself and with a bit of luck the only thing that will limit my range is the amount of drink I can carry.	Time: 2:47:36 Dst: 49.19m Av: 17.6mph Mx: 34.3mph	Av 26.41km/h (it failed to record the first eighth or so of the ride) Route: View Cambridge Orbital 5 in a larger map	~20°C (it rained in the morning again but had cleared up by the time I left)
North Cambridgeshire 9	18/05/11	New personal best, and on the same day I submitted my dissertation (two days early, which is nice)!	Time: 1:24:02 Dst: 26.75m Av: 19.1mph Mx: 25.2mph	Av 30.97km/h	~14°C (it rained just before I left and the forecast was threatening thunderstorms – nearly didn’t go at all but for the duration I was out not a drop fell!)
North Cambridgeshire 10	19/05/11		Time: 1:27:09 Dst: 26.74m Av: 18.4mph Mx: 25.2mph	Av 29.94km/h	~16°C
North Cambridgeshire 11	25/05/11		Time: 1:25:05 Dst: 26.79m Av: 18.9mph Mx: 28.4mph	Av 31.01km/h	~18°C
Cambridge, Cambourne, St Ives, Ely	29/05/11	There was a very strong wind from the south; my average speed all the way up to Ely was 19.3mph (and I'd done 40+ miles by the time I got there). It really slowed me down on the way back down though!	Time: 3:26:42 Dst: 59.61m Av: 17.3mph Mx: 39.8mph	Av 27.97km/h View Cambridge, Cambourne, St Ives, Ely in a larger map	~19°C

I found something almost worthy of being called a hill, and it seemed to be asking for a picture:

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling and tagged cambourne, cambridge, cycling, dissertation, ely, personal best, st ives. Bookmark the permalink.

SO39-40, CUCC T4, SO41

Posted on February 26, 2011 by Dave Comment

Last week was pretty busy (two interviews and one dissertation presentation) so I decided not to cycle. This week:

Cambridge Semi Orbital 39 average moving speed: 27.95km/h.

Cambridge Semi Orbital 40 average moving speed: 28.81km/h (17.9mph) according to My Tracks but 19.0mph according to Cateye (30.57mk/h). The weather was great – I hope the trend continues.

CUCC T4 average moving speed: 26.90km/h. This was just over 30 miles, so after stopping outside for Fitz for 10 minutes I went out again: Cambridge Semi Orbital 41 average moving speed 25.57km/h. Low much more because of the traffic I got stuck in along Newmarket Road due to emergency gas works and less because of the distance I’d already done; I was doing 20+mph most of the way until I approached Fen Ditton (the reason I switch between km/h and mph is because I have My Tracks report in km and the Cateye computer report in miles). The two rides combined totalled 57 miles.

CUCC T4 route (MyMaps functionality has returned to My Tracks):

View CUCC Training 4 in a larger map

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling and tagged busy, cambridge, cateye, cycling, dissertation, interview, my tracks, mymaps, presentation, weather. Bookmark the permalink.
SO37-38, O4

Posted on February 13, 2011 by Dave Comment

Cambridge Semi Orbital 37 average moving speed: 27.45km/h.

Cambridge Semi Orbital 38 average moving speed: 28.67km/h – brought down a little by systematic error due to me having to walk around road works in Cottenham.

Cambridge Orbital 4 average moving speed: 26.34km/h which would already be a reasonable improvement on the previous best of 22.54km/h. However: that speed is as reported by My Tracks and according to a post on the user/dev group, a recent change is causing average moving speeds to be underestimated. This is consistent with the fact that my Cateye computer reports my average moving speed to be 17.0 mph (27.36km/h). Pretty pleasing for a 50 mile route!

The majority of the ride failed to record, with My Tracks reporting only a 44.35km total distance. This was not however due to My Tracks but instead due to today’s nightly build of CyanogenMod 7 for the HTC Hero (build number 20); several times when using the phone I noticed it was failing to get a GPS fix; clearly not My Tracks at fault. Luckily I was also recording the route with Route Tracer to contribute to the dataset for my dissertation and the G1 running CyanogenMod 6.1 had no trouble maintaining a GPS fix for the whole ride. I’ve exported the GPS location data from the Route Trace as a GPX file and imported it into My Tracks; which gives the above figure of 26.34km/h.

Route (using dissertation code again to render points on OpenStreetMap tiles as I’m waiting for the dust to settle after the My Maps/Fusion Tables shake up – route points are in green as one of the recent enhancements to my dissertation dataset visualisation tools is that route points are colour coded by transportation mode):

Update (26/02/11):
My Tracks once again has upload to MyMaps functionality. As I’m currently logging all rides I do with Route Tracer so I can add them to the dataset for my dissertation, I hadn’t bothered to backup the My Tracks routes when changing the configuration of my HTC Hero (whether that be removing the Market version of My Tracks to test out the new feature I developed or installing a new build of the CyanogenMod 7.0 Nightly Builds). For completeness now that MyMaps functionality has returned, I today generated GPX files from the Route Traces and imported using the My Tracks import functionality that I developed (which got added to the Market version along with the return of MyMaps functionality).

SO37 according to the imported Route Tracer data was done at an average moving speed of 27.32km/h whereas the original My Tracks record reported 27.45km/h.

Likewise for SO38: Route Tracer data – 26.95km/h, My Tracks record – 28.67km/h.

The reason for this is that Route Tracer dumps data directly from the sensors without any preprocessing whereas My Tracks filters anomalies. It seems that this has resulted in an underestimate of the stationary times. My Tracks assumes GPX data is accurate/has been filtered and so the anomalies get through (which is also why those routes have very high maximum speeds).

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB

This entry was posted in Cycling and tagged cambridge, cycling, orbital, personal best, semi orbital, systematic error. Bookmark the permalink.
SO 35-36, CUCC T3/Potholes, Punctures and Gales

Posted on February 5, 2011 by Dave Comment
Cambridge Semi Orbital 35 average moving speed: 28.93km/h – another new best for this route, though again probably helped by the removal of the stop-start bit in town on the way out.

I hit a pothole that was hidden from view by a bus until it was too late. I think I was doing about 20mph, but may have started to slow at that point for the approaching roundabout. The hole was about a foot in diameter and three or four inches deep. My bike made a pretty nasty sound but I kept my balance. On pulling over to check the bike I realised the bars had rotated in the pop top holding them in the stem. I checked for other damage but I couldn’t see anything else. I suspect the bar slipping absorbed a huge amount of my downward momentum that would otherwise have done wheel or fork damage.

Not having an Allen key with me I came back with the bars in their now considerably rotated position (such that the drop straights actually point upwards at the back). Surprisingly it was quite comfortable; I think I might keep them like this for my next full ride and see how they are over distance.

Cambridge Semi Orbital 36 average moving speed: 27.86km/h – experienced the worst cross winds yet on this route. My Tracks now fails to upload the track to Google Maps (but Docs statistics work fine), and from what I can tell this is because the Google Maps Data API has suddenly been deprecated. Apparently the My Tracks team are working on an alternate upload mechanism. Not that it matters for SO36 as it’s the same route as the previous few rides anyway. More alarmingly, on this ride I noticed a creaking sound coming from the front forks and couldn’t remember whether I’d heard it before hitting the pothole on Monday. Fearing the worst I thought the forks might be damaged, but having done a fair amount of reading and subsequently inspecting both the fork and wheel I’ve found nothing to suggest they are damaged. The really quite conclusive evidence is that I was able to reproduce the creaking sound by scraping the front mudguard against the inside of the fork crown. So, false alarm, but I was pretty worried for a short while before inspecting it properly.

Route:
View Cambridge Semi Orbital 35 in a larger map

The final ride for this post is my 3rd CUCC training ride. Bullet points rule for this:
- Gale force winds of maximum speed 50 knots and mean speed 26.3 knots.
- Unpredictable and very gusty winds made for hazardous and not particularly enjoyable conditions – winds which are often present on the Semi Orbital route are comparatively steady and predictable and are worth having as they make up for the lack of hills – but the ones today were in no way pleasant.
- The winds were strong enough that:
  - At one point they made me pull a wheelie.
  - I sometimes pulled over, stopped and got off to wait while lorries passed.
  - Sometimes 35 mph could be done with casual effort, and other times 10 mph was a flat out job.
- There had been meant to be two groups – fast and not so fast.
- While cycling at the back of group and before we’d split off a not so fast group, unable to easily see potholes in advance, I hit one and got a pinch flat.
- Shortly after hitting the hole and replacing the punctured tube I lost the still monolithic group and due to the winds struggled to catch up.
- I at first decided to carry on in the same direction and try to repeat the CUCC T1 route.
- Partly due to struggling to recall the route and more because I really didn’t like the winds but didn’t want to just head straight back (having only done about 15 miles at this point), I decided to head back up to the Shelfords and follow the last quarter of the “Full Orbital” route I did a few times last year which I thought might be better because a) I know the route and wouldn’t be stopping and starting all the time to check the map, which isn’t particularly fun b) I knew the roads would be reasonably quiet, and suspected that they would be less affected by the winds than others – plus there are a couple of almost-qualifying-hills which would be preferable to the wind.
Wind speed and direction graphs (source: http://www.cl.cam.ac.uk/research/dtg/weather/daily-text.cgi?2011-02-05):

What I suspect was the pothole I hit (I didn’t take the picture at the time but when returning along the same road in the opposite direction):

Pleasingly I managed to turn what started out OK and then started going bad into something good. Total distance 65.50km (40.69 miles), average moving speed 25.57km/h (15.89 mph). The pothole was somewhere on the road going south from Little Shelford to Whittlesford.

My Tracks still fails to upload route maps to Google Maps due to the the Google Maps API being deprecated. Hopefully My Tracks will start using Fusion Tables soon and convenient uploads to Google Maps will be possible again, but for now here’s an image of the route produced from the Route Trace I was also creating:

Update (26/02/11):
My Tracks once again has upload to MyMaps functionality. As I’m currently logging all rides I do with Route Tracer so I can add them to the dataset for my dissertation, I hadn’t bothered to backup the My Tracks routes when changing the configuration of my HTC Hero (whether that be removing the Market version of My Tracks to test out the new feature I developed or installing a new build of the CyanogenMod 7.0 Nightly Builds). For completeness now that MyMaps functionality has returned, I today generated GPX files from the Route Traces and imported using the My Tracks import functionality that I developed (which got added to the Market version along with the return of MyMaps functionality).

SO36 according to the imported Route Tracer data was done at an average moving speed of 26.30km/h whereas the original My Tracks record reported 27.86km/h.

Likewise for CUCC T3: Route Tracer data – 23.83km/h, My Tracks record – 25.57km/h.

The reason for this is that Route Tracer dumps data directly from the sensors without any preprocessing whereas My Tracks filters anomalies. It seems that this has resulted in an underestimate of the stationary times. My Tracks assumes GPX data is accurate/has been filtered and so the anomalies get through (which is also why those routes have very high maximum speeds).

Here is the Google Doc with all the stats:
http://spreadsheets.google.com/ccc?
key=0At0EKwdiLZmYdFg4Mk9fdHltdWlGeWpQTHMzM3RjU3c&hl=en_GB
This entry was posted in Cycling and tagged cambridge, cycling, deprecation, fork, fusion tables, gales, personal best, pinch flat, pothole, puncture, route tracer, wind. Bookmark the permalink.