xEM affected by temperature changes?

sweet. i will prepare a care package.

Wait until I clear it with my boss. Most likely he won’t mind, but let’s make sure first.

If he’s okay, you can send me a few to put in each chamber: I’ll stick them in a piece of duct tape attached to the back wall. There can be quite a few of them in each strip of duct tape.

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I could test one or two from -80C to 100C

Pretty much dry Ice to boiling water a bunch, no scientific way. And it would only be as many times as I can do it.

Speaking of testing - if my boss is okay of course - there is another device we have you might be interested in: we have a drop tester. Essentially it’s a carriage onto which we attach one of our devices, and we drop it repeatedly from a height of 2 meters until the device fails. It doesn’t get used all the time (just for product design and component supplier qualifications), but again I could tape a few chip to the carriage and leave them there. It probably does between 100 to 500 drops per month.

Is it possible that your feet being cold resulted in poor placement on the reader due to lack of sensation?

No: the reader I use is high-power / long range: it reads from 4/5" away easy. Same as this one:

Also, when I realized it didn’t ring, I looked at it and tried to position it as nice as possible several times, to no avail. And then suddenly it started working again as it always did.

Any chance it was the reader not the implant?
Just thinking of all possibilities

Nope: the reader worked fine with the EM in my hand.

I thought of all that too. The only remaining possibility I can think of is that it was somehow disabled temporarily, either by temperature, or by a loose solder joint - possibly the latter caused by the former. If that’s what it is, the problem is bound to reappear some day. I sure hope not…

I have a remedy, but you won’t like it

If the implant is damaged, it’s too late for your remedy :slight_smile:


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He needs something like this, to keep the barefoot feel.

your product go on top the platform yes, not being hit by the impactor, but riding on top of it?

Assuming the boss approves, any chance you could take photos of the thermal cycling and video of the drop tester with chips on? … for the testing page?

Yes that’s right: the product is attached to the rail that’s screwed onto the sacrificial block of wood (the “impactor”). There’s a bit of unused flat space above the horizontal aluminum bar the block of wood is screwed onto: I’m thinking of taping a few chips there. They’re so light they won’t damage anything.

And of course, I can tape a few chips directly under the impactor, for repeated massive squashing testing.

Also, I’ve been meaning to add a proper hit counter to that device for a long time. I could simply add a reader at the bottom of the guillotine and catch one of the chips passing by. That would be a good occasion to implement a counter, and a dead-or-alive check for the chip at each hit at the same time. I could even ship the data to you, to add a live counter on one of your pages (as in, “that chip has survived xxx hits so far”) :slight_smile:

My boss is cool. I don’t think he would mind, since there wouldn’t be any identifiable information in the photos or videos. But I still want to run that one past him because, well, I can’t just go misuse the facilities willy-nilly. Also, our product aren’t consumer products, and there might be restrictions dictated by our customers. But I doubt it.

Lemme check with him on Monday.


I just ordered 3 of those WiFi NFC readers to query the status of the chips remotely :slight_smile:

To reply more visually, this is the range of the ACM08Y reader I use at work, with the IAR EM4305 in my hand, and the xEM in my foot:

Kinda hard to achieve poor positioning on the reader :slight_smile:

And yes, sad ole me is at work today.


Only rosco would see it as normal to be sat with feet on a high power reader and waving around his feet on camera :sweat_smile:

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Nothing terribly extraordinary to me…

On the other hand (pun), think what you will, but at least if someone wants a long-range reader, or an implant in the foot, or both, you gotta admit that’s pretty good documentation material right there :slight_smile:

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That’s a neat reader, but I can’t believe they’re charging €89 for it. Must have some excellent proprietary firmware.

That’s the price of laziness. You can do cheaper with an arduino, an NFC board and some time to put it all together. But I want plug and play. So I pay a premium for the privilege.