After registering you will be given a consumer/API key and secret which you will need to use my python library. Once you have your key and secret, download the python library with the following command:
git clone https://github.com/trtg/pyfatsecret.git
The library comes with the example below that demonstrates its usage.
To use the example, replace the strings 'your_key_goes_here' and 'your_secret_goes_here' with the key and secret you were assigned after registering as a developer.
Note that the example above makes use of pandas to plot timeseries. You can get the latest pandas with this command:
git clone https://github.com/pydata/pandas.git
I've tested the example above with the stable 0.7.3 release as well.
Once you paste your key and secret into place and install pandas you can run the example as follows:
python example.py
Assuming you already have some data recorded with fatsecret, you should get a plot like the one below after running (click on the image to see a larger copy):
The Withings wifi scale is a great bit of hardware, much more visually appealing than my handmade equivalent and wifi makes it standalone, also a big advantage over my bluetooth scale. I've been using the scale to log my weight and using fatsecret to track caloric intake for a while now and decided it would be nice to make a dashboard integrating data from both sources. The plots on Withings' website leave much to be desired. Thankfully, both Withings and fatsecret have APIs which make third party apps possible. Below I'll show some code that uses the rauth library to access both services. rauth provides OAuth 1.0/a, 2.0, and Ofly consumer support. You can install rauth using easy_install:
sudo easy_install rauth
Before using the Withings and fatsecret APIs, you'll need to register as a developer, you can do that by following the links below:
Withings developer registration:
https://oauth.withings.com/en/partner/add
If you just want to extend the code I provide further down you can fill an arbitrary value for the "Application Website" and "Organization" fields and leave the Callback URL blank. Otherwise, fill in those fields according to your needs.
Once you've registered as a developer with both services you will have your Consumer Key and Shared Secret which you will need to send API requests.
Now grab my python code from github:
git clone https://github.com/trtg/pywithings.git
The git repo has two files: withings.py(the actual library itself) and example.py (seen below). Open up example.py and fill in your consumer key, consumer secret, and the email address you used to register with Withings as indicated. Using the library is pretty straightforward: instantiate a withings object and then just call get_weights() to retrieve a list of weight measurements and an associated list of dates (in seconds since the epoch format) which you can then use however you'd like.
Note that the very first time you run example.py you will be prompted to authorize the app to access your withings account by pasting a URL into your browser. Once you go to that URL and login, you will see a screen like this:
After you click "allow" you will see an oauth token string as shown below. Copy just the part after "oauth_verifier=" , in this case PZBDNyyuxDnGkeMxccY.
Paste the "PZ..." string into your terminal where prompted, hit enter, and you should get a graph like the one below.(Click on the graph to see a larger version) I used the python package pandas to treat the weight data as a time series and get nice date labels on the x-axis as well as to plot the smooth red rolling average of the data.
In an upcoming post, I'll discuss similar code that retrieves data from fatsecret to generate plots like the one below:
I picked up a magic trackpad this past friday and decided to see what it was capable of under linux. The video above shows that the magic trackpad hardware provides a great deal of information to the host operating system. As I'd hoped it seems to be nearly as capable as a fingerworks igesture or touchpad in some regards. In the video you can see that the trackpad is able to: detect 10 fingers, track finger contact elliptical size (i.e. along two axes) and orientation, do all the above smoothly at a high sample rate.
The video was created by streaming the debugfs file entry corresponding to the trackpad into a pygame application. The pygame code parses the apple protocol packets to determine ellipse sizes, positions and orientations and then blits them to the screen on transparent surfaces. This code is by no means pretty, in fact "quick hack" is probably a better description. Any suggestions, enhancements, criticisms,etc. are welcome.
If you want to try the code below yourself, you first need to make sure you have debugfs set up properly. Assuming you enabled debugfs when building your kernel, make sure debugfs is mounted and if it's not, mount it with something like:
mount -t debugfs none /sys/kernel/debug/ Now, if you look in /sys/kernel/debug/hid/ you should see a directory whose name corresponds to the address of your magic trackpad. If you switch into this directory you'll see an events file which you can then read with cat, tail, or the python script below.
Note that support for the magic trackpad is still in a very preliminary stage, so getting things working is fairly involved. I'll describe how to play around with the hardware at a low level in the description below.
First, start with a kernel new enough to have magic-mouse support. In my case, I chose gentoo-2.6.35-r5. Now grab the multitouch branch of Chase Douglas's debian git repository. You'll need to copy or merge several files from Chase's kernel source to your own: /drivers/hid/hid-magicmouse.c /drivers/hid/hid-core.c /drivers/hid/hid-ids.h possibly a few others
If you feel like using the same kernel as Chase, just skip straight to compiling his source tree. Once the kernel is built and you've booted into it, it's time to play around with the trackpad.
Depending on the version of bluez you're using, the procedure for pairing to an HID device will vary. In bluez 3.32 you would first set the trackpad as a trusted device using DBUS, which you could either do programmatically or using a graphical tool like d-feet to call the method /org/bluez/hci0/org.bluez.Adapter.SetTrusted("bluetooth address of your trackpad").
Once the device is set as trusted you would need to actually setup a pairing as root: passkey-agent --default 0000 then use d-feet or DBUS CLI to call CreateDevice("BluetoothAddress"). At this point if you call ListDevices() you should a new device corresponding to the trackpad. Once you've paired with the trackpad and loaded the hid-magicmouse kernel module you should see messages in the system log indicating that a new input device has been registered. input: Apple Wireless Trackpad as /class/input/input6 magicmouse 0005:05AC:030E.0005: input,hidraw4: BLUETOOTH HID v1.60 Mouse [Apple Wireless Trackpad] on 00:27:48:09:63:60 input: Apple Wireless Trackpad as /class/input/input7
Note that you'll also want an up to date installation of evdev, otherwise you might get messages like this: evdev.c(EVIOCGBIT): Suspicious buffer size 511, limiting output to 64 bytes. See http://userweb.kernel.org/~dtor/eviocgbit-bug.html
If you want to see the touch reports the trackpad produces you can use the evtest application. In gentoo this is provided by the joystick ebuild. Now if you do ]$ evtest /dev/input/event6 Input driver version is 1.0.0 Input device ID: bus 0x5 vendor 0x5ac product 0x30e version 0x160 Input device name: "Apple Wireless Trackpad" Supported events: Event type 0 (Sync) Event type 1 (Key) Event code 272 (LeftBtn) Event code 325 (ToolFinger) Event code 330 (Touch) Event code 333 (Tool Doubletap) Event code 334 (Tool Tripletap) Event code 335 (?) Event type 3 (Absolute) Event code 0 (X) Value 3097 Min -2909 Max 3167 Event code 1 (Y) Value 2238 Min -2456 Max 2565 Event code 48 (?) Value 0 Min 0 Max 255 Event code 49 (?) Value 0 Min 0 Max 255 Event code 52 (?) Value 0 Min -32 Max 31 Event code 53 (?) Value 0 Min -2909 Max 3167 Event code 54 (?) Value 0 Min -2456 Max 2565 Event code 57 (?) Value 0 Min 0 Max 15 Event type 4 (Misc) Event code 3 (RawData) Testing ... (interrupt to exit)
Now if you touch with two fingers you'll see a slew of output which should include something like: Event: time 1283194689.870573, -------------- Config Sync ------------ Event: time 1283194689.870586, type 1 (Key), code 330 (Touch), value 0 Event: time 1283194689.870587, type 1 (Key), code 333 (Tool Doubletap), value 0 Event: time 1283194689.870589, -------------- Report Sync ------------
