When [Steve Parker]’s girlfriend got a tea kettle that takes voice commands, he suddenly saw his fancy bean-to-cup coffee machine as a technological dinosaur. It may make good coffee, but getting the DeLonghi going is inconvenient, because it runs a self-cleaning cycle each time it’s turned on or off.
Thus began [Steve]’s adventure in trying to turn the thing on with Alexa via Particle Photon. Because of the way the machine is designed, simply adding a relay wouldn’t do—the machine would just turn off and back on, only to start the self-clean again. Once inside, he found it’s controlled by a PIC18LF2520. Further research indicated that it is powered by an off-line switcher that combines a power MOSFET with a power supply controller. [Steve] figured out that the buttons are read via square wave and interpreted by a multiplexer.
The project went into the weeds a bit when [Steve] tried to read the signals with a knock-off Saleae. As soon as he plugged it in, the control board fried because the DeLonghi evidently has no reference to Earth ground. While waiting for a replacement board to arrive, he tried replacing the mux and shift register chips, which actually fixed the board. Then it was more or less a matter of using the DeLonghi’s status LEDs to determine the machine’s state, and then to interface with the Photon and Alexa. Cycle past the break for a ristretto-sized demonstration.
[Steve] didn’t do all this to actually make coffee, just turn the machine on with a voice command. The Photon is totally capable of making coffee, though, as we saw with this closed-loop espresso machine.
“coffe machine, turn of alexa!”
Good reply!
Ingenious!!
“its brain is in the form of a PIC18LF2520 which is a 5v MCU meaning interfacing with it should be straightforward. ”
“The PIC is powered by a LNK364GN 9W off-line switcher which provides non-isolated 5v supply.”
Uh-oh. You can see where this is going…
You only fried the controller board? And didn’t fry your PC or yourself? Lucky.
I’m the author, and yes it was lucky. My expensive 4k monitor which was plugged into my laptop wobbled a little bit when I plugged it in. Irritating that I made the mistake as I twigged that there would be a problem with the grounds when I saw the power board.
I was definitely lucky and serves as a reminder to be careful when working with things you don’t understand.
Reading Steve’s web page, there’s at least a couple of other sites that have exact copies of this HAD article. Have you licensed it out, or are they being really, really flattering?
The whole cheap ripoff for quick dirty money aspect of the web is completely disappointingly inevitable. There’s at least half a dozen sites out there that rip off Wikipedia’s articles, stick them behind a different interface, and pretend they’re some sort of revolutionary new information source. At least Wikipedia’s open licensing allows this. But even if it didn’t, I’m sure most of those sites wouldn’t care.
I’m the author, when HAD posted the article there were a couple of pingback immediately from other sites that just lifted this article and posted as-is.
From my perspective its more exposure, but it must be angering for HAD to deal with this.