Stravomatic: an Android app to automatically start Strava rides

This week-end I remembered that when I got my new phone, it counted my steps on its own, and I looked up why. I discovered that there’s a Google Play Service that enables developers to get the user’s activity (walking, running, cycling etc) and I decided to try to code my first Android app: Stravomatic.

I use Strava since a few years and find it great to keep track of statistics , but sometimes I forget to start it each morning and evening when commuting.

Development went much better than I expected and I think I have a good and reliable app that starts a Strava activity if I start bicycling (or running) (for completeness, because I never run) (apart this week-end where I went around the garden numerous times for testing). It’s a simple app with a settings page and a background component that keeps track of what happens :

As it doesn’t use GPS, and takes advantage of Google Play Services, it doesn’t seem to take a noticeable toll on the battery, so I’m quite happy about that.

I published it on Google Play : Stravomatic, and I’m quite proud about it! I hope it’ll help other forgetful people :)

My own homemade BB-8

After having seen the latest Star Wars movie, I, like numerous other geeks, fell in awe with the BB-8 droid, and, like numerous other geeks, I wanted to try and build one.

So, I started by getting a 300mm plastic ball and another of 180mm diameter (which was more of a 160mm ball according to my ruler…), a pair of motors, and got the electronic parts box out of the cupboard, guessing I’d just start and solve problems as they come instead of spending a lot of time with plans, and getting demoralised half-way.


The start was rather easy: get the useless parts out of the balls, and sand them so the paint would adhere.


Then I made a few calculations to create the main board at the lowest possible place, and placed the motors and wheels at each side.


Going on with the battery holder, even lower, in order to help with stability:


Spoiler alert, this USB smart battery didn’t provide enough current, so later it got replaced with a S2 LiPo battery I use in RC cars.


The fun part began, with a bit of Arduino programming. I used a standard 2.4GHz receiver for control, added a 3-axis gyroscope in order to try and compensate wobbling with the motors.


About everything, laid out. Spoiler alert: the gyro is of no use, because the motors, which are DC motors with reductors, are far from precise enough to compensate anything. Also, even if they were precise, they could compensate pitch (front-to-back wobbling) but not roll (lateral).


After upgrading the battery, the first test was rather promising:

And here came the time for the difficulties: adding the mast:


And the head, with magnets to hold it in place, and caster balls to have it roll freely:


Spoiler alert: the very little caster balls did not roll freely at all, and too much approximation in the magnets’ placement made them touch the body’s ball, making very unpleasant sounds (and also the head had that tendancy to fall):

But still, it was promising. So I started painting.





And after hours of masking, painting, re-masking, re-painting, I arrived at an unperfect, but not too shameful result:


Went on with the head…



But with just the added weight of the two “eyes”, it couldn’t sit on BB-8 more than a couple meters… So I ditched it and re-made it from a styrofoam ball (this time of the correct size), and while I was at it, re-made the magnetic mechanism with better magnets, better caster balls and better measurements.



And the result looks pretty good in my opinion!


It also rolls much better, although there are still a few noises and it can look like BB-8 had a few beers:

It took my three weeks to get to this point. I knew I could make it a month, so I’ve upgraded a few things, mostly so I don’t have to open the body each time I want to power BB-8 on: first, a magnetic switch (don’t use a bicycle odometer’s sensor, it won’t accept so much current and will solder itself the first time), which I can use to power on BB-8 from the outside (after a bit of searching each time):


It’s made out of a bendable piece of metal and a magnet.

You can also see there a pair of relays, which are used to auto-power-off the Arduino and its motor shield after two minutes of RC signal loss; this way, I don’t have to open the body to shut it down either.


And I’ve stuck in a little LiPo battery tester, so that it can scream at me when the LiPo’s starting to be too discharged (LiPos don’t like that, and when LiPos are unhappy, they tend to catch fire if you look at them wrongly, so.)

I now consider my BB-8 complete although it’s far from perfect ! I think it wasn’t the easiest robot to start building robots, but then, I enjoyed making it. Maybe next time I’ll do an R2D2, and although the body work will be harder, the mechanics will be a walk in the park.

After building it I’ve watched other videos from other BB-8 makers, and it is really fun to see how many different designs there are. Some are very simple with an RC car at the bottom of the ball, some roll by direct transmission and have turning performed by a fly wheel; some are holonomous robots with multi-directional wheels, some use indirect transmission like mine, but a flywheel to turn (this guy is good, but also has access to great resources, so I do think I could do much better if I had CNC mills, 3D printers and ACTUALLY GOT PAID TO DO IT), and this 17 years old’s model works exactly like mine, but damn this kid is skilled.

HP Laserjet P3005: fuser disassembly and gear kit replacement

Here’s how to disassemble the fuser on an HP LaserJet P3005 printer, and replace the gear kit (which is a part that fails often, reference CB414-67923). First remove the sliding plastic part at the back of the printer, then remove these two screws :


Then remove the big plastic panel, bottom first so it disengages at the top.

Lift these two little tabs so you pull the part they’re attached on towards you, and remove it:


Remove the screw holding the next panel in place (then remove it by putting the cable at the left away, and be careful not to break the clip at the right). I don’t think this is necessary, in reality. I did it because I didn’t know where I was going.


Then unplug the fuser cables (the cover on the power panel comes off with no screws) :



And unscrew the four screws :


You can then pull the fuser away and reach the gears. From left to right, the first one has a plastic tab keeping it in place, which you can pull with a little screwdriver. The second one is free when you remove the first. The third one is freed by the fourth, which is held in place by a weird little plastic piece. The sizes of the pieces are rather close but not identical, watch out for that. More details on this part of the procedure.


How to act like an idiot and cost a free software project money

A few monthes ago, a user made us a €5 donation for Claws Mail’s Windows version. Then asked me over email and Facebook friend request for support on “error messages that pop is starting up prior to sm something da da da” (actual quote).


I just replied that this seemed like he’d need to enable POP before SMTP, and that he’d get better support on the users mailing list.

And this person then filed a chargeback at his credit card company, and consequently, Paypal withdrew €5 from my account, and withdrew an extra €16 the bank charged for processing.

This got me a little disgruntled, to say the least, so I sent Paypal screenshots of the user’s email support request and Facebook friend request, and Paypal forwarded those to the bank.

Yesterday I got news that the bank resolved this in our favor (and I do hope our indelicate user got a scolding :-)), and the €5 reappeared on my account.

The €16 processing charges, though, seem lost forever.


Full story about Claws Mail donations – what they are for, what they aren’t for.

Claws Mail donations: what are they for, what aren’t they for?

First of all, happy new year to everybody !

I’d like to talk a bit about the donations one can make to the Claws Mail project which I’m part of since approximately 12 years now, and tell a tale of something that luckily happened only once.

There are three kinds of donations possible for the Claws Mail :

  • One can opt to donate a certain amount of money via Paypal, from the Claws Mail Donations page.
  • One can opt to buy geeky stuff like T-shirts or mugs from our Cafepress store.
  • And the third one I added when I was really discouraged with maintaining the Windows port, a platform I don’t use: a specific Windows port donation. The amount of money donated is up to the donator, as well as for the normal donations.

We don’t really know yet what to do with the money that’s been donated over the years (and which amounts to €1573 since the first donation in 2006, for the sake of transparency, plus about €200 for the Windows port, and $120 from Cafepress). We plan on doing another meeting someday, and probably use it towards the travel expenses, hotels, food or booze. Probably booze. ;-)

We’re really grateful to everyone who makes a donation to us, each donation makes us aware that our little piece of software helps people in their everyday lives enough to go out of their way and give us something back.

In the same way we’re very grateful for every reply on the user mailing-list, where our community is very nice, helpful, and the flame wars very rare. (There are people on our mailing-list that have been subscribed for longer than I have ever been, they don’t have any questions to ask since years but stay just to help others. Their answers are invariably helpful and I find that this is great to have this sort of community). This was off-topic but I wanted to say it since a while.

So this is how we regard donations: a sort of “thanks” – and until now, that was the case for most people. Sometimes donations come from unknown people, sometimes I recognize the name of a new user, sometimes I recognize the name of long-timers.

But recently, in September, I woke up to three emails:

  • Notification of a €5 donation from John N. – Paypal
  • A Facebook friend request from John N.
  • A personal email from John N.

Let me quote the personal email, because it’s worth it:


Dear Colin: I am sending this email because when using claws-mail I have not even been able to send one message and I must let you know that I am frustrated.I continualy get error messages that pop is starting up prior to sm something da da da… I have no problems like this with either outlook or Gmail.The reason that I am wanting to use Claws is due to privacy issues.I am now using Tor for most of my web surfing and other investigating work which I do.please send me a phone# that I can use to speak to to someone of my issues.

I thought it was very possible that the sender was completely unaware of how things are in the Free Software world, so didn’t think too much about it and just replied with basic help for the first idea that the misquoted error message made me think of, and pointers for getting more help if needed:

Hi John,

It seems that your email provider wants you to authenticate using POP
before attempting to send using SMTP, is this it?
If so, you can probably make it work by checking the “Authenticate with
POP before sending” option, which is located in the account’s
preferences, in the “Send” section.

Hope this helps !

If you have other questions, you will probably have better and faster
replies on the mailing list, where there are a lot of users who know
Claws Mail inside and out ! You can subscribe there:

Also, thanks for your donation, in the name of the whole team, it is
appreciated :)

And that was it. I never read from him on the users mailing-list, so I thought my reply was probably enough to get him unstuck.

Until three weeks ago, when I received an email from Paypal, stating this payment was unauthorized and that the card holder asked his bank to cancel it. Which I found pretty unbelievable. Probably my reply was not helpful enough and John N. thought he was buying a service, then he got disappointed by the service, but instead of asking me for a refund — which I’d have done, because I wouldn’t care, people make donations to us, and if they change their mind, we have nothing against it! As stated earlier, none of us rely on donations to live or anything – luckily! — instead of asking for a refund, this person filed a formal complaint with his bank that his card had been fraudulently used!

The difference between a refund and a fraudulent use complaint, I learned, is that Paypal forwards the bank’s charge of €16 to us (which I can understand). So this cost us €16. Way to go, isn’t it!

So, just out of principle, I did refuse the refund at Paypal, included screenshots of John N.’s emails and friend requesting (!) and also my reply. This makes it difficult to believe that a thief would have used this person’s card to ask for hotline help using the same person’s email address and Facebook account. This doesn’t prevent Paypal from getting these €21 back, but this does make them pursue the matter with the bank. (And I hope this person will get some sort of trouble with his bank for filing wrong claims. I know he won’t be punished for believing Free Software developers may be his personal slaves).

(Update from March 13th, 2014: we got the original donation back, but not the bank’s processing charges)

So, in case anyone else wonders, no, the Donations page is not a way to get custom work (hotline or not) done, this is, as stated, just a thank-you :-) – (Contracting one of the developers for custom work may be possible, for example I may consider it, but not in this manner)

Luckily, this happened only once out of 88 donations, and to the the rest of the 87 donators since 2006, again, in the name of the whole team, heartfelt thanks!

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