Inching Forward

Dancing With Cupertino

We’ve been going back and forth with Apple via iTunes Connect for several weeks now on various things to do with our app, including an unfortunate 8-day delay just because we uploaded a new binary (apparently this restarts the review queue?!).

We finally received an email last week from from the App Review team asking us to review a Rejection in the Resolution Centre of iTunes Connect. It appears Apple want us to send them hardware to review as “We began the review of your app but are not able to continue because we need the associated hardware to fully assess your app features.”.

Why it took so long for them to come to this conclusion or why there’s not a  special process for hardware developers somewhat astounds me. We’re shipping hardware to Cupertino today and the letter in the Resolution Center does offer a glimmer of hope when it says “it may take several days” after they receive the hardware (and not weeks).

We were able to get Test Flight approval for the app after creating a video of it functioning. Test Flight is Apple’s newish beta program. Drop us a note if you’d like access to the next build.


The manufacturing issues that we were seeing with Grow have been resolved. I think we went through something like half -a-dozen reworks of the board, many more interactions of swapping out components, and much head scratching as it should have worked the way it was.

So why didn’t it? Well, the Grow’s soil moisture sensor is something we designed ourselves. The theory of operation is relatively straight-forward: it’s a plate capacitor that is influenced by water molecules surrounding it as water is a dielectric.  A high frequency signal (MHz) is sent into this plate capacitor, is then influenced by the surrounding dielectric (capacitance increases proportionally to the water content of the medium surrounding it),  is then rectified and filtered, and a then read.

The levels of capacitance change being measured are pretty small: they’re in the low pico-Farad range.  One of the first clues that something was very wrong on the pre-production units was that the output signal was always very high and had virtually no variance in it.  We even bought an LCR meter to triage this.

So what was the problem? Well, to cut a long, arduous story short: the design was good (it’s still exactly the same), the components were fine (despite worries about switching speeds for diodes), it was what I’ll term a “layout hygiene” issue. The traces that were carrying the soil moisture sensor signals were being influenced by the rest of the PCB and picking up close to 1 nano-Farad of ‘stray’ capacitance. High-speed analog design appears to be a lot less forgiving than digital, which is exactly what all the text books say 🙂 Unfortunately, it required several rounds of fabricating slightly different PCBs, hand assembling them, and observing the results — which took weeks 😦

Climate and Sentry: short delay on receiving the first shipment back from the CM (Contract Manufacturer). We’re expecting them back early next week and then a larger shipment shortly after that (December 1st is the current date our CM is giving us).

Thermo and Water:  scheduled for manufacturing by the CM as soon as the PCBs come back.

Grow: we’ll give the green-light for the CM to start work on this in the next couple of days once we’ve done some more testing. We’re very confident, but also don’t want to manufacture (and send you) a product with issues!


I’ll write a separate update on Mesh (our gateway/bridge) and our platform this week.

m + s + l


  1. marc this story seems never ending… I am sorry for you (and also for me as still waiting)!
    how come Apple cannot publish a software without the hardware? have you a direct telephone numebr or are you just handling everythign by email? by my experience direct phone contact speed upi the process usually.
    Please register me to the beta.
    looking forward to the next update saying shipped, your item will arrive this date..; hopefully still an update in November

    1. Hi there, all App Store approvals are handled through iTunes Connect (which is a developer portal). This is, unfortunately, Apple’s process….no phone calls, no direct emails, no expectations of how long things take.

      I’ve never personally heard of having to send in hardware, but someone we know anecdotally mentioned he’s come across it once before with an “appcessory”.

      The apps and the hardware are very much intertwined — you need the hardware to do anything with the app. Although we wrote the “demo mode” which fakes sensor data but still uses the actual sensor screens to try and get ahead of this issue, but apparently that wasn’t enough.

      1. yeah… somebody in Apple wants to have a free sample! 😉
        (or a proof that it works)

      2. Two years ago, we sent in our Bluetooth Low Energy Advent Wreath to Apple after we realized that for an appcessory, they require the hardware. It took us a while to realize this, as the error message was somewhere well hidden and said “metadata missing”. What? Metadata?

        We used to joke about whether BMW would have to send Apple a car if they ever incorporated BLE in their cars.

        Since then, I’ve heard contradictory information that it may or may not be sufficient to submit a video of the working hardware.

  2. Yikes, sorry to hear that Marc. I’ve had some trouble with Apple’s review process before as well, very frustrating.

    We realized 5 days after we’d submitted the first binary that we’d forgotten to change a very small feature (literally one line!), and so upon submitting the fixed binary we were placed at the end of the queue.

    What you wrote about the layout hygiene was very interesting, I had a couple ECE friends explain some of the more technical details to me. I find it pretty remarkable how such a tiny amount of capacitance can create issues with the readings.

  3. This is sounding a lot like vapourware, excuse after excuse. And that hardware one is a doozy

  4. not buying your story mate.
    You told us you are ready months ago and now nothing is basically ready.
    All your stories are very confusing – sorry for beeing brutally honest

  5. Any update? Are the climates on schedule?

  6. Where’s the update to the Mesh gateway? You guys keep failing to communicate on the schedule you’ve promised. Shipments continue to be delayed, and I want a refund.

  7. We’re ever so busy working behind the scenes to overcome our challenges. We’ll be posting an update just as soon as we have new information to share. We hear all of your concerns and appreciate you hanging in there. Please stay tuned!

  8. Update overdue – we are so busy. BS it takes you 5 minutes to write an update.
    Just keep your promisses – if you can’t son’t promisse.

    No information provided just bla bla

    Please condider a refund – I’m sick of this

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