Commissioning with Android vs. iPhone

I just got an imp & hannah board in the mail today and was very excited to start tinkering. I already knew everything I needed to do to commission the imp and was ready to send the blink up code via my phone (I’ve got a Motorola Droid Bionic w/ the Electric Imp app, obviously). After sending the blink code a few times, I kept getting the “fast red” LED flashes to indicate that the blink up message failed; also, sometimes the card would simply stop blinking any colors at all, and I’d have to un/replug the card into the hannah board.

I was slightly frustrated, but still had high hopes that it was something silly that I was overlooking. That seemed to be the case when I read that the ambient light may be an issue while sending a blink up, so I headed to a room, turned off all the lights, and sent the blink code, but it failed yet again. It failed several times in the dark, so I was starting to wonder if there was a deeper issue, i.e. defective imp, etc…

Just to cover all of my bases, I asked to use a friend’s iPhone (4s w/ i0S 6) to try the blink up.


I’m not sure what the difference could’ve been between the two, but I may try and take a video of the two sending the blink up code side-by-side and see if I can spot any differences (which maybe unlikely considering the frequency of the blinking).

Overall - glad it’s working, yet upset that that’s what it took to get everything up and running.

As a side note - the “Commissioning an imp” page on the dev wiki makes references several times to options unavailable in the blink up app in the “Notes for WiFi Network Configuration” section. The “show typing” button for displaying the network password doesn’t exist, and the “WPS PIN setup button” is not named correctly (I believe it is still just “Blink Up”). Would be nice to see some consistency between instructions and reality…

Anyways - onto tinkering!


The difference is that android phones (at least pre 4.1) drop frames all the time, which makes staying in sync very hard.

We have an improved version that will be out at some point which has a half-speed mode - this allows the imp to work out when frames are dropped, but does take twice as long to do blinkup.

Thanks for the notes on the wiki instructions; they refer to an older (internal) version of the app, we’ll make them match reality!

I had another thought on this. the iPhone has very even and complete sub-pixles groups. Many android screen use a cheap version of oled with incomplete sub-pixles groups. Blinking holding the imp 1/8 of an inch away or trough a pane of glass may even out the color and provide better results.

The pixel layout really doesn’t matter; the light pipe takes in the light from many, many pixels at a time. It’s the dropped frames that are the real issue in our testing (the new slower blinkup even works on the $75 resistive-touch android tablet we found on Amazon) :slight_smile:

When is this half-speed mode version going to be available?

Soon (sorry, don’t want to commit to specifics) but I’ve emailed it to you in case you need it.