SM01-IR cheap smart switch with IR blaster

I recently picked up a smart socket from Amazon for $9.99 which not only has a 16A capacity and energy monitoring, but boasts an IR transceiver as well. This link goes to what looks like an identical product, although with a different name:

After prying it open, I found that there is a 5-pin 1mm set of header vias which purport to expose Vdd, GND, TX, RX, and DOWNLOAD. I soldered wires to the vias, and connected it to my serial programmer. I did the “hold button down while powering on” step, which resulted in a LED on the board lighting up. I was unable to flash the device (communication failure) at 115200, 57600, and 9600 bps.

Here’s a link to pictures from the FCC filing:

Has anyone mucked about with one of these units yet? I’m hoping to use it to manage some things as an IR blaster.

Can you verify that pushing the button while trying to flash is grounding the correct gpio pin? What firmware did you try to flash with?

I haven’t yet checked to see that GPIO0 is being grounded by the button, but I think the different boot behavior when the button is held down is a good sign. Will report back later when I can get the device and a multimeter in the same spot.

Are you using esp tool to flash, I have needed to use this in the past with other Esp’s. Might want to try swapping the TX and rx wires on one end. I’ve seen them labeled wrong before.:roll_eyes:

If you can positively identify the gpio 0 on the esp chip, then a jumper wire from there to ground while powering up via serial communications (not main power) will remove any doubts about the button and allow flashing.

I concur, definitely looks like an ESP.
Oh… Goody another toy to play with
Try flashing tasmota to find out if the power monitor works. I doubt that the IR will do anything but your never know

Yeah, esptool. I did try swapping the TX/RX lines. No change. I had a moment to probe around but didn’t find GPIO0 for sure. There’s nothing labeed that way, although there is a test point labeed “RST”. More later.

You can try to get GPIO 0 directly on the chip, or follow the trace:

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The difficulty with that is the chip is on the bottom of the daughterboard, and it is soldered in place. I’m going to try and desolder the pins to get it free. Hopefully I won’t wreck it in the process.