The Fitbit Blog

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Fitbit QA

Hi Everyone,

We’re still on track here.

The main thing that we’re focused on now is developing testing systems to test each Fitbit as it goes through the assembly process. There’s several steps to the testing process.

The first is testing circuit boards. The Fitbit has 3 circuit boards. 2 are in the wearable Fitbit and 1 is in the wireless base station. After each circuit board is assembled, it is placed into a test fixture. One of our actual test fixtures is show below:


An operator places the circuit board into the fixture and then closes the lid on top of the board. The fixture contains many metal pins which make contact with special areas of the board. When the lid is closed, these pins make firm contact. Through these pins, we’re able to run tests which exercise various parts of the board automatically. Here’s a closeup of the board after the fixture lid has been closed on top of it. The black rubber feet gently push the board onto the test pins:

Closeup of the test fixture making contact with a board

Basically, we want to ensure that the right components have been placed on the board, that all the components are connected properly and that there are no manufacturing defects such as electrical shorts. We also do some mechanical tests such as automatically pushing the button to make sure that it’s connected properly. Here’s a solenoid switch that when commanded, pushes a button on the circuit board:

Solenoid switch to auto push buttons

2 of the boards are also connected by a cable, so we also do tests to make sure that the cable has been connected properly. Here’s an overhead shot of a test fixture that tests the cable connections. You can see the yellow cable drooping between 2 of the boards:

Testing the cable connections

Here’s some shots of the overall test fixtures:

Overall fixture

Fixtures in the lab

Once the circuit boards have passed testing, they are assembled in the Fitbit case or enclosure. Once enclosed we do another series of tests to ensure that

1. The enclosure process has not damaged the boards or the cable
2. The charging contacts and the USB cable have been properly soldered

We plug the Fitbit into its charger both ways to test proper charging contact connectivity and also connect the base station to a PC to make sure that the USB cable has been soldered properly and that the PC can communicate with the radio inside. We then do a series of special button presses on the Fitbit to put into a self-test mode, which does a final exercise of its functionality, including lighting up the display, checking components, etc.

In short, all this is to ensure that the Fitbits will be working well when they arrive on your doorstep.

FYI, 4 of our team are also flying to Singapore early Wednesday morning to start the assembly process. I’ll keep you posted on that.

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56 CommentsLeave a comment

  • Great update, very exciting!

    One question I didn’t see answered above is how each fitbit is tested to make sure it is accurate. Your FAQ states “Calorie data from the Tracker is very similar to those from energy expenditure measurement devices used in clinical research.”

    Other devices already on the market like ActiGraph, bodybugg, and GoWear fit, have clinical research data verifying claims. GoWear fit listed the accuracy as follows: “Total calories for free living activities: mean error < 10%”.

    Does the fitbit have a stated accuracy for calories burned? Can you explain which energy expenditure measurement devices used in clinical research you are referring to in your FAQ?

    The reason I bring this up is this Wall Street Journal article from today:

    This made me wonder what the actual accuracy is for the fitbit besides the statement that it is as good as other clinical research products. The WSJ article points out that the products used for clinical research can have dramatically different accuracy levels. If the fitbit had a mean error of 30%, that could mean a 900 calorie error if I burned 3000 calories a day, that is a lot!!

    Any information on this would help me understand the little fitbit better.

    PS: I saw the fitbit in the latest Wired, congratulations on that as well.

    Thanks and good luck during the assembly process!!

  • This is exciting…the date is getting closer and closer. Thanks for all the hard work you are putting into getting it correctly. Can’t wait!!

  • Is there going to be any public beta testing on the web app? I think I read in an earlier post that you would open up the web application to some folks prior to shipping. Is this true?

    Looking forward to getting my fitbit!


  • Thanks for the update, love the thoroughness you are taking to make sure we get a quality product. How is the website looking. what are your plans with the website. will it be released early or not until we receive our fitbit unit!

  • It is exciting to read what all it entails to get the Fit Bit onto production and distribution. Thank you for the update.

    I agree with many others. How is the website coming along?

    Getting excited for my fit bit.

  • Hi everyone,

    Sorry, it’s taken us a bit longer than expected on the website, mainly because there are many more test cases than we expected for our QA people to go through. I think we’re going to hold off on allowing access until the Fitbit device ships, so that we have a bit more time for our QA people to stress test the site and uncover any remaining issues.

  • Hi Maria,

    Thanks for pointing out that article.

    The error rate for the Fitbit is going to be closer to the Actigraph mentioned in the article than the BodyBugg. The primary reason is that the Fitbit and the Actigraph utilize a single sensor (motion) while the BodyBugg uses multiple sensors including motion and heat. The Fitbit is optimized towards walking, running and general household activities and the more of your day is composed of those types of activities, the more accurate your results will be.

    However, I really don’t think you should depend on using any of these devices as precise calorie measuring tools. For instance, note the actual details of the BodyMedia study:

    “The company cites a 20-person study published last year in the online edition of the British Journal of Sports Medicine. In the study, a similar armband called SenseWear, made by BodyMedia for physicians and academic researchers, was used to estimate calories during two hours of activity.”

    20 people…2 hours…in a lab environment. This is very far from replicating any type of real-life scenario and this is the type of scenario that generates the best case 90% accuracy number. Throw the BodyBugg into a situation where it is deprived of one of its sensors (such as biking, where very little arm motion is detected) and you’ll see that it will be harder pressed to meet that 90% number.

    Again, the best use of any of these devices is not to consider them precise scientific instruments, but rather as motivational devices that are great for observing day to day trends. As the article states: “The rate of error is likely to be consistent for a given person, so the devices “will be accurate in showing improvement” in physical activity levels, she adds.”
    That’s pretty much a spot on observation.

    Remember, motivation, rather than precision is key. Take for instance, Weight Watchers, which is pretty good at as a program for weight loss. Their concept of “calories burned”, which are activity points, is really crude and imprecise. Yet, the key thing for Weight Watchers is not the precision, but that the activity points serve as a motivational focus point for you to increase the amount of physical activity you do.

    The way we see the Fitbit device is that it’s an nicely designed, affordable device that is practical to wear, is connected seamlessly to a good web service and works great as a motivational tool. In no way, should you treat it as a scientific instrument or as a miracle device.

    That said, it is pretty darn precise at measuring steps and I think it will prove to be one of most accurate, if not the most, in that respect. Check out some of the results in one of our previous blog posts:

    Hope this response helps.

  • Congratulations on being less than a month away from delivery! Been a long time in coming — I’m sure you are happy to be nearing the end! I agree with many of the comments you made regarding Maria’s post. Motivation is very important. I do, however, think that accuracy is important as well. I plan to log my food religiously — I think that information alone will be invaluable. However, I am REALLY looking forward to being able to see how much less (or more) I should be eating as I try to lose weight. I think this will only work well if the fitbit is relatively accurate about how many calories I am burning each day. Do you know if the fitbit will generally under or over estimate? Maybe I can try to account for the error myself if it is generally consistent in one direction???

  • Just saw you in the July edition of WIRED, really got me excited and I pre-ordered. As you said, its more about knowing what you are doing throughout the day then a perfect assessment of calories burned. I’ll feel like an elite athlete or a movie-star with the Fit Bit with the ability to track my progress throughout the day and make necessary changes. Can’t wait for it to ship!

  • I’ve got an interesting idea to solve (or at least help out) the accuracy issue of calories burned. I completely understand that we shouldn’t be focusing too much on the accuracy of how many calories we have burned, but more on our trends.

    Would it be possible to give us access to some settings on the website that we could tweak to dial in a more personalized estimation of calories burned for specific movements that the Fitbit measures?

    Also, a “learning” feature would be nice too. For example, if I logged every single thing that I ate/drank and kept detailed records of my weight fluctuation on the website, could you have the website kind of reverse-engineer a more accurate calorie burn measurement for myself?

  • I’m curious if the developers have heard about the Nike Sportband – I ask because I bought that 1st gen as soon as it came out also. It’s similar in that it’s something you wear, it uses sensor to track how far you go, cals burned, etc).

    Unfortunately, it was plagued with moisture issues getting into the LCD quite easily (people sweat when they run, or running in rain, or even general humiditiy). They ended up recalling the product and are about to release gen2.

    Has the fitbit been tested in humid/sweaty conditions? I realize it’s not waterproof for swimming as the site says, but hope it holds up a lot better than the first gen of the Sportband.


  • Hi I can hardly wait. I jumped on this product last fall when I first saw it advertised in the newspaper. One of my questions as related to calorie burn, etc. is how much personal information will we program into it so it knows our weight? I am using this as a motivational tool to keep me going on the weight loss journey. Currently, I do CURVES and wiifit exersices quite religiously. Will it help keep track of my heart rate as I do those workouts? I can hardly wait to get it and connect to the web site. Thanks for your persistance in getting this to us.

  • Hey guys nice little write up in Fast Company (July/August 2009 issue). The pressure is on, are you still on target?

  • I emailed to change my shipping address but haven’t received a response from you guys for a week. How long do I need to wait to get confirmation that my information has been updated?

  • I received an email confirming my address was updated but avenue I live on is one street off. Looking over 2 emails I sent I wrote down the wrong one originally but was correct the 2nd time I emailed on the situation. Sorry about that, glad I didn’t get a response originally or else I wouldn’t have noticed my error. Whew! :)

    I did send back a reply letting aware of my error.

  • Just read about fitbit in fast times magazine, wow. I cannot wait to be able to preorder one….should be a boon to my goal of being fit for life.

  • It sounds as if everything is going as planned. Congrats. I also am looking forward to the finished product along with everyone else. But, “Amanda” brings to light something that I personnally forgot about. Is the unit itself at very least “moisture resistant”, I re-read a few other blogs of this site and really didn’t find an answer. I am a heavy sweater and would hate to have the “Bit” for a week and I short it out(haha). I hope you can answer in your next blog. Thanks in advance.

  • @Amanda and @John

    I don’t know if you have had a chance to read their FAQ section, but they do seem imply that the Fitbit will be able to withstand sweating and being in humid conditions as it is “water resistant”.

    From their FAQ Section:

    Is the Fitbit waterproof?
    No, the Fitbit is just water-resistant, so it is not recommended that you wear it while swimming. The Fitbit is also not meant to track calories burned while swimming”

  • I see the website has been updated that FitBit will be available in August vice Spring. Looks like it is becoming a reality.

  • How do you all think this will compare to the bodybugg and gowear fit? (This question is for anyone reading this post)

  • @Eric

    Appreciate the feedback. The sportband from Nike was water resistant too – didn’t work out so well – moisture issues almost immediately. Hopefully fitbit design is better.

    Sure wish fitbit would open their site up to us.. or at least some user forums (moderated with maybe some answers to questions!)

  • Hi – just checking to see if you all are on schedule for July 27 now that we are less than 2 weeks away.

    Can’t wait, would love an update.

    Will you all be emailing all the pre-orders soon to confirm charges to our credit cards? I assume that will be the sign everything is on track


  • When are we going to receive another update? I’ve been anxiously awaiting my fitbit since October and we haven’t had an update in a month!

  • One week to go until your vendor was scheduled to ship to you. Any update?
    Still on schedule?
    How long do you expect it to take you to ship the pre-orders?
    When will our Credit Cards be charged?
    Will you open the website up before you ship the pre-orders?

    Mr P

  • Hey everyone.

    We’re still here. I’ll make a full blog post in the next day or so. We’re still on track to start shipping some units to our US warehouse sometime next week. Our current big problem is throughput…due to some additional steps we had to add to the assembly process, the time to build a Fitbit and its Base Station is about 600 seconds. I’ll explain in a lot more detail in the next post.

  • @amanda: we added sales tax to be on the safe side with the local tax authorities. We have offices in both CA and PA and I believe those are the only places where the tax should be showing up…let me know if it isn’t.

  • @melvin2000

    We’ve tested the Fitbit Tracker to IP52.

    “Limited dust ingress protection and water spray < 15 degrees from vertical” To be safe, though, I would limit its exposure to water.

  • Dawn and other:

    We were actually planning on sending final confirmation emails last week, but we’re a bit behind on integrating the software that handles our payment and logistical operations. This involves communications with our 3rd party warehouse, submitting your payment info to the credit card company, etc.

    I’ll let you know when those will start going out.

  • Thanks for letting us know your here. I check the website 3x a day or more for updates. I can’t wait for the fitbit and to show it off to everyone. I have a feeling it is going to really help motivate me.

  • @James

    Thanks for update. I’m in PA so that explains it, just didn’t expect you had offices here. If you ever need to hire someone, even part time, I’m available!

  • Kinda weird…the front page says that you are not taking pre-orders…yet, it still lets me pre-order it? Can I still submit an order?

  • 7/24. How many units will be in your first allocation and how many pre-orders do you have? Are you still on track for the 7/27 initial shipping? When it gets this close to the predicted shipping date a daily update should be posted. Any news is better than no news.
    Be well,
    George B

  • there was a ‘little’ word-play when it comes to the Shipping Post (previous). If you read carefully he says:

    ‘Fitbits will begin shipping from our manufacturer during the week of July 27th to our warehouse in northern California (about an hour drive from our office). We are shipping everything via Fedex Priority Air to get it to our warehouse as quickly as possible. The moment the shipment touches our warehouse, we plan on turning as many as we can around the the same day and shipping them out to you.”

    That means they will actually be shipping out AFTER 7/27 depending on how long it takes to get from the Manufacturer to the warehouse (im hoping not that long… as in the same week, but that might be wishful thinking)

    Either way i’m excited and still waiting for the units i ordered… and suprised at the lack of updates as we near actual shipping date….

    do we have access to the website yet?

  • @John,
    I just got back into the US yesterday. Please give me a day or so to recuperate :) I’ll be making a post by this evening (Sat).

  • I don’t think there is any real problem (in letting you recover), except that in your post of 21 July you said “I’ll make a full blog post in the next day or so.”…I believe that amped up expectations a bit. I know it did for me.

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