Jinvoo SM-SW101-3 Switch teardown

November 28th, 2019 robin Posted in Home, Home Automation | Comments Off on Jinvoo SM-SW101-3 Switch teardown

Sometimes people want to see what the inside of a device looks like… so do I! 🙂 So I took apart my new Jinvoo SM-SW101-3 and took some pictures:

I was able to flash it to tasmota easily with tuya-convert and connect it to Home Assistant. :yay:

There’s a template for it too so configuration was a breeze and shortly after I was able to integrate it to home assistant and set up some automations to turn on scenes – I’ve only used two of the three buttons so far so I’ve still got one to play with!

As far as I can tell, the button LEDs are linked to the relays; they cannot be lit independently of the relays. I don’t have anything connected to the relays at the moment, so they click (and draw a little power) when the button is pushed.

With tasmota flashed I measured about 0.5W with all switches off and about 1.3W with all relays on.

Stop coil whining on Gosund SP111

November 18th, 2019 robin Posted in Uncategorized | Comments Off on Stop coil whining on Gosund SP111

The Gosund SP111 is a great wireless plug with an ESP8266 controller built in that can switch and measure mains power. It can be flashed OTA with tuya-convert so you don’t even need to do any soldering to get custom firmware such as tasmota on it. The form-factor is also impressive being so small and at about €12/piece the price is hard to beat. The only major downside is that with low/no load it can have that annoying beep / whistle / whining that comes from a badly positioned / not fixed coil (“coil whining”).

Please be careful – you’re dealing with mains electricity here, so unless you know what you are doing and are ok loosing your guarantee for opening and meddling with the insides of a device PLEASE STOP HERE!

The process is the same for both the V1 or V2 SP111, but you can tell if you have a V2 because they are rated to the much higher 3450W.
Unscrew with a phillips screwdriver (PH 0x50 is about the right size)
Pull off the clear plastic cap
Unscrew the board from the plug pins (one screw in each hole) and and remove the purple rubber pad
Unclip the antenna from the board
Carefully pull the board out of the housing. Pull the antenna cable to the little gap on the side as you are doing this so that it does not get jammed between the board and the housing
This is the coil which is whines…
Put a dab of hot-glue on the coil affixing it to the relay (white block in the centre) behind. Be careful that the glue does not stick out further than the coil or it may jam when you are trying to re-insert the board into the housing.

Now re-assemble everything again carefully remembering all the screws, clipping on the antenna again and the purple pad which keeps the antenna connector in place. When you plug it in again you should find that it no longer whines. 🙂

Pro-tip: this method (putting a dab of hot-glue on the coil) is the solution for nearly all whining power supply issues – the only difficulty is getting them open non-destructively and identifying the offending coil.

Let the children cry!

February 14th, 2019 robin Posted in Pro-Parenting | Comments Off on Let the children cry!

Yes – the title is click-bait… But bear with me! 🙂

Kids fall over and bump themselves all the time, and as a parent your automatic reaction when you think your precious little meat-ball has hurt itself is often to jump up, squeak in concern and proclaim “Ouch! Are you ok?! Does it hurt very badly?!” (or something to that effect). In this short interaction you have already made three assumptions:

  1. Ouch! – the child got hurt
  2. Are you ok?! This implies that they probably are not.
  3. Does it hurt very badly?! They are hurt and you need to find out how much.

Sometimes you may be right, but 9 times out of 10 you are not and by saying this you will be teaching your child the expectation: “when I hit my head like this everyone else expects that it will hurt a lot, that I will not be ok, and that I will need a lot of consoling to get over it”. Kids are great at fulfilling our expectations, and if you repeat this behaviour they will learn to behave as you expect them to.

My tip to you – when a child (seems to) hurt itself, bite your tongue and observe. If the child does not immediately start crying before it looks for you stay calm. If the child looks at you expecting a response, try something jovial like “Oopsi-doopsi!” and smile. If it really hurt itself it will let it be known – don’t worry about that – and if it needs consoling then it is really important that you do that and without delay. But if it smiles back at you and continues on with play, it’s quite likely that it just got a bit of a surprise and didn’t really hurt itself, and you have just helped it learn the difference between a real ouch and a light bonk that is not worth getting upset and loosing play-time about.

Just to be clear – this recommendation is _not_ intended to be tough or insensitive to children. It is really really important that when a child is hurt and needs its parents that you are there for it.