TRÅDFRI wall switch

This hack will modify the TRÅDFRI remote into an attractive wall switch.

The project homepage (in Danish): https://www.thingiverse.com/thing:3655354

This information is under CC BY-NC-SA 4.0 license.

Photos

63 mm wide. Typical color choices are white or dark gray - silver combo.

The switch are 45 x 45 x 12 mm, and does not require room behind it.

With a smaller bezel the switch can be 50 mm wide.

Both sides of the custom circuit board.

Custom print on plastic is possible.

But why?

Problem, step 1

Using TRÅDFRI on a sofa lamp is great. You can turn it on and off from your phone, and you can place a remote switch where you like.

However when you start using TRÅDFRI to replace existing ceiling lighting, you will soon realize a problem: If the light is turned off by the wall switch, you cannot turn it on by remote or app, because there is no power going to the light.

Solution, step 1

Replace the wall switch with a remote.

Problem, step 2

This looks unattractive, and does not fit into the existing wall switch and socket design.

Solution, step 2

Transfer the electronics from the remote to a switch that fits the design. The the design is so compact, that is does not requires space behind it, and can be mounted directly on the wall.

Problem, step 3

This design is for the FUGA system, which is only used in Denmark.

Solution, step 3

You can use converters to make it converter to fit the size used in the rest of Europe.

Problem, step 4

This does not look as attractive.

Solution, step 4

Be inspired by this hack, to make a solution that fits your wall switch and plug system. Be careful with mains electricity, an the note of the the law and regulations in your country. This hack avoids mains electricity by being mounted directly on the wall.

Building instructions

This guide is for at batch of 100 units. If you want a smaller amount like 20, you can order circuit boards without components, and order all the components at RS Components. However it is much easier and cost effective to follow the guide and make 100 units.

Materials needed

• ZigBee module from IKEA TRÅDFRI remote control
• Plastic for LK FUGA svagstrømstryk
• Circuit board and components
• 3D printed plastic for the back

Order circuit board with components

1. Go the the web page https://jlcpcb.com/
2. Click "QUOTE NOW".
3. Upload svagstromstryk_PCB_2019-09-14.zip.
4. Set "PCB Qty" to 100.
5. Set "Surface Finish" to ENIG-RoHS (not required, if you want to save cost).
6. Change thickness til 1.0 mm.
7. Enable "SMT Assembly" -> "Assemble your PCB boards".
8. Pick "Assemble top side".
9. Click "Confirm".
10. Upload svagstromstryk_PCB_2019-09-14_BOM_JLCPCB.xlsx as BOM file.
11. Upload svagstromstryk_PCB_2019-09-14-top-pos_JLCPCB.xlsx as CPL file.
12. Click "NEXT".
13. Review and confirm all the components.
14. Click "NEXT".
15. Review Parts Placement.
16. Click "SAVE TO CART"
17. Continue the Checkout. I prefer UPS over DHL for delivery, because customs cost are less.

Order additional electronic components

Below we see the highlighted components we need to buy. Most components are included on the board. Some components are cheaper or better at DigiKey. The rest we buy at RS Components.

Amount	Reference	Included on PCB	RS Stock No	Digi-Key Part Number
400	S1-4	No	479-1491	450-1130-ND
100	S5	No	135-9404	CKN10814CT-ND
100	S6	No	154-2583	CKN10849CT-ND
500	C1-5	Yes	135-9020
500	R1-5	Yes	679-1459
100	R6	Yes	810-1741
100	D1	Yes	654-5391
100	Q1	Yes	690-0127
100	BT1	No	219-7960	BK-888-ND

Go to RS Components and order

• 400 x 479-1491 (1000 x is cheaper at DigiKey)
• 100 x 135-9404

Go to DigiKey and order

• 100 x CKN10849CT-ND
• 100 x BK-888-ND

Order original LK FUGA plastic front

The plastic can purchased by these EAN numbers:

Color	Buttons	Center
White	5703302140836	5703302132244
Light gray	5703302140829	5703302132237
Dark gray	5703302140843	5703302132251

You need 200 buttons and 100 center plastic.

If you want laser engraved buttons, they can be ordered at bestil.lk.dk.

Remember to choose "IHC svagstrømstryk", not "IHC wireless". They look similar, but are not compatible.

Print the back side

Download the appropriate model

• With support: svagstromstryk_lukket-bagside_med-support.stl
• Without support: svagstromstryk_lukket-bagside_uden-support.stl

Tolerances are very small. The space inside must be 41.6 mm wide. Depending you the type of plastic used, the model must be enlarged between 100.2 and 100.8%. The "ironing" feature in Cura is also very useful, because it make assembling easier. Remember to pass this info along, if someone else print the model for you. Teste one, before you print a lot.

Extract the TRÅDFRI ZigBee module

The ZigBee module is inside the TRÅDFRI remote. It can be purchased directly by the number 304.431.24. It is also included in a variety of bundles.

The extraction of the module is quite hard, and the remote is fairly expensive in some regions. Alternatively you can to use the ZigBee module from other TRÅDFRI devices, if you reprogram it.

The TRÅDFRI signal repeater is the easiest product to extract the module from. Just push on the USB plug, and it pops open. It is only soldered on 4 pads.

The bulbs are harder to open, but are easy to desolder, because it is only soldered on one side. The 400 lm white bulb is the cheapest option to the the module.

Most TRÅDFRI products has the ZigBee module. You can recycle broken or unused devices.

Except the ON/OFF remote and the dimmer remote, they don't have the module.

Assembly

1. Solder the components on the circuit board in this order:
   1. top side
      1. Small components (already done if ordered with components on).
   2. Switches and buttons
   3. back side
      1. ZigBee module
      2. Battery holder (remember to fill the center pad with solder)
2. If you used an alternative ZigBee module, you must reprogram it now. This is described here: https://drive.google.com/drive/folders/1SMhPC1echgKWlc-W4N89JKZ2KiJ_H_ZD
3. Insert battery, note the polarity. There is a plus sign on both the battery holder and the battery, they should match.
4. Inset the circuit board into the plastic back. Mount the battery side first. It might be necessary to remove some plastic under the tabs.
5. Mount the frost side plastic.
6. Test that everything is working.