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Posts tagged: pebble

Simulating Pebble GPath in Rocky.js

By , 08/17/2016 3:56 PM

RockyJS is a black magic voodoo from Pebble Dev team. It allows you to run your JavaScript code on the actual smartwatch (unlike PebbleJS that runs on the phone). When RockyJS debuted it ran as a simulation in a browser, but since then it matured and now runs in Pebble emulators and on actual hardware.

RockyJS changed drastically since that web release. It resembles C code less and takes more standardized JavaScript approach. During that transition some features were lost. One of them is Pebble GPath concept – a graphical object that consist of set of coordinates that you can freely move and rotate. In particular missing commands gpath_move_to, gpath_rotate_to and gpath_draw_outline that move, rotate and draw the GPath. When I was porting my first Pebble watchface to Rocky I used those extensively. You can read about that implementation complete with the source code here. But now the commands are gone and I needed a substitution. Continue reading 'Simulating Pebble GPath in Rocky.js'»

Future Time – watchface for Pebble smartwatch

By , 07/17/2016 1:32 PM


This is the face of the future.

Two faces actually – because you get both analog and digital face – and it’s up to you which one to use. You also get eight predefined color themes as well as ability to set each color individually. This face also provides weather and fitness tracking at your fingertips. And it just looks cool.

Key features:

– Digital or Analog face type selection
– Multiple color themes as well as custom color settings (or you can leave it on auto and the color will depend on battery level)
– Weather (powered by Forecast.io), Step Counter, Distance Walked, Sleep Hours
– Bluetooth Connect/Disconnect alert of configurable intensity with visual clue
– Battery level represented by percentage number as well as visually by outer perimeter of dots (also by watchface color – if in auto color mode).
– Visual step goals


After installing watchface you have a 3-day trial period to explore all the features and different aspects. At the end of trial if you like Future Time and want to keep it – it’s just $1.50 USD via Kiezel Pay payment system, you will be prompted to enter code and follow few easy payment steps. Once purchased – the watchface is yours permanently, no matter what Pebble or what phone you use, as long as you keep the same Pebble account.

You will need to get free key for weather services at https://developer.forecast.io – this is one time procedure.

Design by Paul Joel http://www.pauljoel.com

CobbleStyle 2 – watchface for Pebble smartwatch

By , 07/16/2016 11:41 PM


CobbleStyle is back! This time with THREE modes to display the time: analog, digital or BIG TIME! With complete customization on what information you want displayed. With pre-designed color sets and complete color customization. Make CobbleStyle 2 how you want it!

Key features:

– Three Ways to display the time: Analog, digital, or BIG TIME!
– Multi-language support
– Anti-aliasing text and graphics.
– Date / Weather / Bluetooth connection.
– GPS Location.
– Week number.
– Local time.
– Alternative timezones.
– AM/PM.
– Seconds counter.
– Pre-designed color sets.
– Custom colors.
– Custom text.
– Backlight when charging option.
– Bluetooth alert options.
– THREE weather providers – choose most reliable for your location
– Master Key weather provider control via https://www.pmkey.xyz – store all your weather API keys in one convenient location

Health Info:

– Step Count
– Live step goal bar.
– Custom step goal.
– Distance Walked
– Time Active
– Calories burned at rest
– Calories burned while active

Only $0.99 USD

After installing CobbleStyle 2 you will have a three days trial period to explore all the features and different aspects. At the end of the trial if you like CobbleStyle 2 and want to keep it, it’s just $0.99 via KiezelPay payment system. You will be prompted to enter code and follow easy payment steps. Once purchased, the watchface is yours permanently, no matter what Pebble or phone you use, as long as you keep the same Pebble account.

Design and Art Direction by Paul Joel – http://www.pauljoel.com

API keys for weather providers

By , 06/29/2016 5:00 PM

Many apps and watchfaces for Pebble smartwatch provide weather information and many of them require you to have your own key, unique for each weather provider. Here’s how to obtain API keys for 3 major most popular weather providers:

  1. For Forecast.io register at https://developer.forecast.io/ – and at the very bottom of the page there will be long string of letters an numbers – that’s the key.
  2. For OpenWeatherMap register at https://home.openweathermap.org/api_keys and you will see a form create your API key there
  3. For WeatherUnderground go to https://www.wunderground.com/weather/api, click LOGIN button, fill the form to create account, go to “Key Settings” in menu and generate your API key there

It is *highly* recommended once you get your keys – save them at https://www.pmkey.xyz service. Then all you have to remember to get them is simple 5-digit pin and more and more watchfaces (CobbleStyle 2 being one of them) use this service for easy key retrieval.

Pebbles, rectangles and stack overflow

By , 04/20/2016 2:17 PM

UntitledWhile working on my Pebble watchface “Future Time” I have encountered persistent annoying problem – watchface would run for a while and then crash – and not only crash, but actually restart the watch. What made this even more frustrating – after 3 restarts in a row Pebble would revert to recovery mode and complete firmware reinstall was required (did I accidentally write a Pebble virus?).
When I dug into device logs I found out that every restart was given reason: “Dangerous Stack Overflow”. Which is kinda strange – I don’t have any recursions nor deeply nested function calls nor large local variables. I tried lots of things – including extreme ones like declaring all local function variables as global or static – nothing helped.
Finally Christian form Pebble developers forum shed a light. He pointed out that I use a lot of GRect constructs which is basic rectangle building block for pretty much anything from defining layers to graphics functions. I used GRect inline directly inside function calls, which I thought wasn’t a big deal, after all “everybody does that” – including Pebble in its examples. Well, as Christian pointed out those GRects are kind of local variables, and either memory is not reclaimed fast enough when they go out of scope or they spring memory leak.
Keeping this in mind I created a global GRect variable and when needed to use a GRect in local function, first I’d assign it’s value to the variable and then use variable in the function.
So something like this:

static void layer_update(Layer *layer, GContext *ctx) {
   graphics_draw_rect(ctx, GRect(10, 10, 30, 30));
   graphics_draw_bitmap_in_rect(ctx, bitmap, GRect(20, 20, 40, 40));

Becomes thus:

GRect temp_rect;

static void layer_update(Layer *layer, GContext *ctx) {
   temp_rect = GRect(10, 10, 30, 30);
   graphics_draw_rect(ctx, temp_rect);
   temp_rect = GRect(20, 20, 40, 40);
   graphics_draw_bitmap_in_rect(ctx, bitmap, temp_rect);

That’s it. This simple change cured the plague, no more crashes, restarts or recovery – just smooth sailing.

Trump wants to bring Pebble home

By , 04/01/2016 12:01 AM

Trump on PebbleDonald Trump’s plan to “Make America great again!” would have you spending a whole lot more dough on your next Pebble smartwatch.

Not surprisingly, that would be the logical consequence of the Republican presidential front-runner’s latest ambitious promise: Getting Pebble to start manufacturing their products in the US instead of China.

“We’re going to get Pebble to build their damn watches in this country instead of in other countries” Trump said in a speech at a rally in Supai, Arizona.

The Donald’s claims are made to appeal to a voters having difficulties finding jobs in the US. Pebble, the world’s most innovative company with cult of followers, designs its best-selling Pebble Time, Pebble Time Steel and Pebble Time Round in the US but relies on partners in China and Chinese factory workers to assemble all of them. But what would be the price to build those “damn watches” in the US? Even a rough estimate of the basic costs shows it’s an unrealistic option, leading to a Pebble smartwatch with a potentially jaw-dropping price tag.

To keep things easy, let’s just observe salaries of workers occupied with assembling a Pebble. A labourer at Chinese manufacturing factory gets paid roughly $400 a month before overtime, according to the New York Post.

Now assume Pebble goes the cheaper route and utilizes a factory in Wyoming or Georgia, which happen to have the country’s lowest minimum wage at $5.75 an hour. Working 8 hours a day, 5 days a week, a US worker will earn $824 a month, or more than double the Chinese labourer. And if Pebble were to utilize someone in its home state of California, where the minimum wage is $9 an hour, the monthly pay is $1,400, or more than triple of the chineese.

And that’s ssuming you have number of workers with enough technological skills to do the job (and you don’t) and also assuming those workers will work for minimum wage (they will not). After awhile, things don’t add up.

While there are a number of other factors that go into a Pebble, including the components, shipping, marketing and research and development, doubling the labor costs could significantly hike up the price of a Pebble. Current price of Pebble Time is $150 — will you pay for the same smartwatch $300? $400? Or more?

“Twice the price is a very modet estimate” says Clara Mileshti, an analyst at Dumas CostEff, about the price hike of a Pebble if it were manufactured in the US.

In another speech, Trump proposed a 35 percent tax on products built outside of the US. So at a minimum, that would mean your next Pebble Time’s price could start at over $200.

Pebble declined to comment on Trump’s comments and didn’t want to get into the potential math of bringing watch manufacturing back the US.

Trump’s comments ignore the fact that Pebble does buy some of its components from US companies, including LEG’s Cortex-MI5 processors. The company said earlier that it believes it affects jobs creation in the US throug encouraging developers to learn and and create software for their appstore ecosystem. And by the way, creating and submitting an app to Pebble appstore is free for developers.

Pebble couldn’t afford to build a watch in the US at a reasonable price. Making a more costly, “Made in the USA” product is not an option, especially as consumers start to wise up about how much they’re spending on their smartwatches. Today Pebble is the leader in low-cost efficient watches. But alternatives are cropping up.

So strike it up as another crazy, wild claim by Trump. Or is it?

Unblock my heart, i mean, iPhone for Pebble geocoding

By , 03/29/2016 11:15 AM

Cobblestyle I’ve recently updated code for Cobblestyle Pebble Watchface to take advantage of very cool geocoding service called Nominatim by Open Street Maps.

Nominatim is used in two places: Direct lookup is used in watchface’s config page to lookup coordinates of a place by its name for custom location setting; reverse lookup is used to lookup location name by its coordinates to display name on actual watchface.

It was working fine – on Pebble watches connected to Android phones. It was failing miserably on iOS, so iPhone Pebble users were getting neither location nor weather updates. And it was pretty puzzling for a while until I obtained logs from running watchface thanks to invaluable help from Robin.

Turned out iPhone Pebble app was plain simple blocked by Nominatim service, every attempt to retreive location resulted in message being sent back “You have violated acceptable policy”. Which was kinda surprising since I just started using the service. When I contacted Nominatim support, they told me that apparently some Pebble app running from iPhone abused the service pretty badly, running hundreds of requests per second. And since the only way they can detect requesting app is by it’s User Agent string – all apps spotting iPhone Pebble UA were blocked.

Support suggested to set UA string specific to the app so it could be easily identifiable. Standard approach to set headers on xmlHttpRequest object is .setRequestHeader(..). Unfortunately by many browsers and clients it is considered unsafe to spoof UA via request headers. Fortunately iOS allows that, so all I have to do is catch and ignore erros in other clients. Basically this line of code solved the issue:

try {xhr.setRequestHeader("User-Agent", "Cobblestyle Pebble Watchface");} catch(e){}

Thanks to this as of version 2.19 Cobblestyle watchface correctly displays weather and location information. Yay.

Fire on High or Framebuffer in Rocky.js

By , 02/11/2016 10:23 PM

First things first. DISCLAMER: Everything described here is a hack upon a crude hack and most likely, barring a divine intervention, won’t work in final product. And I apologize in advance to Pebble dev team if my attempts at “hacking” seem silly. Now to business. Pebble SDK offers very cool framebuffer API that allows developers to address display memory of the watch directly. This makes possible creation of many cool special effects (matter of fact EffectLayer library uses framebuffer extensively).
Rocky.js is JavaScript incarnation of Pebble SDK and it made me wonder whether it offers framebuffer access. Turned out it is hidden, but it’s there. At least at the latest commit at the time of this article it is. If you take a look at source file html-bindings.js you will see that binding function looks something like this:

Rocky.bindCanvas = function(canvas, options) {
  var framebufferPixels = new Uint8Array(module.HEAPU8.buffer,
                                         canvasW * canvasH);


  var binding = {



  return binding;

Continue reading 'Fire on High or Framebuffer in Rocky.js'»

Persistent configs in Rocky.js watchfaces

By , 02/09/2016 10:56 PM

Rocky.JS is the first step in Pebble journey to run JavaScript directly on the watches (unlike Pebble.JS which runs on your phone). Previously I described how to convert a simple watchface from C to Rocky.js. But that was a static watchface with unchangeable settings.

Here I will show how to create a configurable watchface in Rocky.js similarly how classic SDK faces can be configured. You will be able to reuse your existing config page – and if it was set to work with Pebble emulator as well as real watch – you will reuse it without any changes at all.

First let’s review how classic Pebble SDK calls config page. In PKJS (JavaScript) portion of Pebble code usually there’s a piece like this:

  function(e) {

If user requests config of face/app – this event fires and opens page with configurable options from specified URL. After user modifies settings usually “Save” button is clicked on that page and code similar to this executes:

$('#xbtnSave').click(function () {
   var location = (decodeURIComponent(getURLVariable('return_to')) || 
                   "pebblejs://close#") + 
   document.location = location;

Here, first we determine which location to redirect config page to. If parameter "return_to” is passed in query string (here custom function getURLVariable() is used to extract individual parameters – look it up), so if this parameter is passed – it means config page is called form the emulator and we use it for redirection. Otherwise we use standard "pebblejs://close#" URL to save settings into real watch. We also take settings object which has our collective options combined, convert it to string and add to the URL as a parameter. Page then is redirected to resulting URL and Pebble emulator or real watch takes care of processing parameters.

So, how can we (re)use it in a Rocky.js watchface? Continue reading 'Persistent configs in Rocky.js watchfaces'»

Rocky.js – Pebble watch coding in JavaScript

By , 02/08/2016 3:59 PM

Pebble never ceases to amaze. And every time you think – this is it, they reached the pinnacle of awesomeness – they surprise you again. This time they did pretty much the impossible – ported their C SDK to JavaScript, by creating Rocky.JS project. Ultimate goal is to run JS directly on the watch hardware – this will open way to huge number of new developers who hesitate to dive into depth of C. Meanwhile it provides ability to run Pebble code directly in a browser! It’s a lot of fun and as a bonus you can insert Pebble watchfaces directly into your website as evident by living watchface you see here.
Watchface you see running above is called Meyer Object it’s been available for Pebble watch for a while and I decided to port it to Rocky.JS Continue reading 'Rocky.js – Pebble watch coding in JavaScript'»

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