SwitchMote available with PSU R3

The full SwitchMote kit is available again. I had to redesign the PSU cover and some 3D printed spacers which fit the new PSU R3. Everything is pretty much the same as before, except that there’s significantly less soldering to do. The PSU R3 is also available separately. All the small passives are now SMD soldered. There are now 4 screws that balance the cover a little better than before., and the FTDI programming header is offset from the edge.

You do the programming the same via an FTDI-Adapter and a double length male header which is provided in the kit.

SwitchMote PSU R3 release

The SwitchMote PSU is now at revision 3, here are the changes:

  • DC side is now SMD assembled, no more through hole components
  • 2OZ copper PCB
  • with the RECOM RAC02-05SGA there is no need for a fuse, only a MOV at 230V
  • although the DC side TVS footprint is left there, the specs of the AC-DC do not warrant a TVS on the DC side
  • same relay options as before – two 10A/250V relays or one 16A/250V relay
  • same control via AVR Moteino
  • optional footprint for ACS711 hall effect current sensor, this is experimental – it offers an analog output proportional to the AC current flowing through the SwitchMote relays. Adding this sensor requires cutting the main HOT trace where indicated and soldering solder jumpers on the bottom from the transducer’s DC side (isolated) to the Moteino side.
  • 4 symmetric mounting holes for a better enclosure – planning to make a 3D printed PETG enclosure and make the SwitchMote available with it

The kit will include the SMD assembled PCB along with the RECOM PSU, relays, MOV, screw terminal and headers. Optionally it can be ordered assembled at an additional cost.

New SwitchMote RECOM supply and sale!


The RECOM certified PSU used in the wireless SwitchMotes was a pretty expensive part of the kit. This was sourced from Digikey/Mouser and used to cost around ~$11 in volume. There is now a new PSU with identical size and pinout, very similar specs but even more certifications, weighs less, lower noise, same Austrian quality. The really great part? It costs just ~$6.50 making the SwitchMote kits price go down!

The SwitchMote2x10A, SwitchMote1x30A and SwitchMotePSU kits are now on SALE, check them out!


SwitchMote with single 16A relay

SwitchMote  and SwitchMote PSU are now available with a single 16A relay, instead of dual 10A relays. I realize this is most often the case that a second relay is not really necessary, except when replacing dual gang switches with a single gang SwitchMote, so I found this higher rating relay which can be soldered as shown in the guide. I also added the option to get it with a single 10A relay since most light applications now use either CFLs or LEDs and 16 amps are not really necessary for such small loads.

This new 16A relay requires removing two of the leads to make it fit the SwitchMote PCB, this is also added to the guide:

Worth noting here that the dual relay SwitchMote (a.k.a. 2x10A) is now the official kit that deprecates the older single 5A relay SwitchMote – that one has been discontinued and will only be available by special order.

SwitchMote latest features & R&D

I’ve long wanted to make a professional enclosure for SwitchMote and do away with the acrylic covers and all the screws and spacers. All these parts add a lot of overhead and cost to the kit.

SwitchMote was designed to be a DIY modular/hackable/educational kit (so far at least) that uses mostly “off the shelf” parts. In the past months I’ve invested into a SwitchMote enclosure design. The PSU side would be cool in clear plastic, below is a rendering:

The good news is this can be made very solid and simply snaps onto the top and bottom PCBs with some cleverly designed tabs, without the need to use any spacers or screws or other exotic mating methods. I like to simplify and KISS everything. The enclosure can also accomodate the recently released PIR option, below is a prototype:

The bad news is the eye watering cost to make the moldings for this. The cost of UL certified fire retardant material is also expensive. I would need to put SwitchMote in HomeDepot or go to Shark Tank for that to make financial sense. So at this point I’m looking at alternatives, one option is silicone molds that can produce a few hundred units at most.

Another option is to go the 3D printing route and make these right here in the shop. I’ve had a prototype built on an FDM printer and I’m quite happy with the quality and strength, the downside is detail. Because the front panel is the only exposed part, that could be covered in something else that is nice and smooth, and perhaps allow for any color the user wants. 

There are many other ideas cooking as to make SwitchMote more feature rich, realiable and easy to use. For now an enclosure would be one step closer to professional looking (yet Arduino based) IoT switch (that doesn’t suck).

Ideas, suggestions, feedback and help are always welcome!

SwitchMote PIR motion sensor option

Quite excited to announce the new PIR sensor option on SwitchMote, this was requested by a user and is finally available in the shop. The chosen PIR sensor was the ultra low power Panasonic EKMB1201111 (same as offered in the MotionMote Kit). It’s a fantastic sensor, very small fully contained package, the only down side is these sensors are expensive. For this reason the kit is now significantly discounted for a limited time! You may source your own PIR of course (and mention you want the PIR parts at checkout), a forum user reported the older revision of these sensors might be found for cheap on eBay.

The SwitchMote Guide was updated with instructions for this change. Mainly the kit will come with 2 buttons and the PIR instead of 3 buttons, along with a required 10K pullup and the front cover matching the PIR sensor. Here is the updated kit content, notice the front PCB is different:

Controlling AC outlets with SwitchMote

Sometimes you need to remote control an AC outlet that powers something (like a heater or a light or motor etc). There are different IoT solutions out there  like the PowerSwitch Tail which allows hooking up your arduino/IoT device of choice and control 1 outlet.

Naturally, having created the SwitchMote kit, and after being asked in the forums if this could be modded/used to control AC outlets, I made a quick video of how to implement an AC outlet switch-box using a SwitchMote 2x10A, allowing control of 2 independent outlets with local button control as well as visual feedback via the status LEDs of the SwitchMote.

New SwitchMotes available

I’ve released some new SwitchMote kits after some requests by different users of SwitchMote. All SwitchMotes are wireless AC actuators, some designed to replace conventional light switches for the purpose of automating household light switching. Specifically there is a new dual 10A relay SwitchMote (and PSU):

There is a new assembly guide for this specific variant posted here. Here are some photos if it assembled and compared to the original SwitchMote:

Also there is a new single 30A relay SwitchMote PSU for heavy AC loads. The PCB for this particular one has double copper thickness to support the loads (2oz copper). Note that the relay has parallel posts at the top for heavy duty connectors as an option.

The demonstration of this PSU has already been posted in a video a few days ago:

The demo in the video uses the TxRxBlinky sketch. All of these are available at the Low Power Lab webStore. The SwitchMote guide page has been updated to include these new variants and the SwitchMote sketch was updated to support the new dual relay SwitchMote 2x10A.

Library updates & MoteinoMEGA support

Following the MoteinoMEGA release, the RFM69 library and examples have been updated to support MoteinoMEGA, there are significant changes to the library and you should get latest. The MoteinoMEGA Arduino Core has been released and needs to be installed in the Arduino/hardware folder (stable v1.0.5 tested working) before uploading to MoteinoMega. The Eagle source and schematic/board files are published in the LowPowerLab github repository. The Moteino page was updated to reflect the addition of the MEGA to the Moteino family.

The Wireless Programming library and examples are updated to fix bugs and support the MEGA as well. Another important change is the introduction of radio.ACKRequested() function in the RFM69 lib which should be used instead of the radio.ACK_REQUESTED variable. This ensures that ACKs requested by a broadcaster are ignored and only targeted ACKs are responded to. Please update your examples for proper wireless programming behavior. All examples have been updated to reflect this change. Also the SwitchMote sketch has been updated.

I consider this a major release and hence your constructive feedback and notification about anything that was omitted is appreciated.

SwitchMote R2 Kit released

Update: The assembly and user guide for SwitchMote R2 has been drafted and is published here. SwitchMote is now available at the LowPowerLab webshop. The guide for R1 is still available here. Pricing is overall about the same as before, unfortunately the isolated Recom PSU used in the kit is a very pricey component, but people asked for isolation and certified components, so here we are.