Readme v Češtině

Table of contents

• Introduction
  • What is it?
  • What can it do?
  • What is expected cost?
  • How does it look like?
  • How big is it?
  • Is it safe?
  • OK I'm sold! What do I need to build it?
• SeeedStudio Fusion PCB
  • How to order PCBs
• After you build it
  • OK DONE! What's next?
• Software
  • Swifitch default software
  • Custom software
• Enclosure
  • 3D Printed
  • Purchased ABS box
• Soldering cheatsheet
  • Back side
  • Front side
• Credits
• What's next?
• Photos

Introduction

What is it?

ESP8266 based WiFi enabled relay board, that will let you easily turn any light or any plug to SMART one. Easily control using HomeKit (other HW needed) or using any MQTT based SmartHome application. Or if you are skilled developer, write any code you want.

What can it do?

Main purpose is to turn things ON or OFF. But it can do lot more than that, swifitch is equiped with header to connect another 4 digital devices and 1 analog. These could be sensors etc.

If you need, by sacrificing one of the data pins, you can get 5V for your 5V sensors.

⛔ Be aware that swifitch's pins are not 5V tolerant and cannot accept 5V on any of the pins provided, and it will damage the ESP.

There are also two jumpers. One is for enabling deep sleep and the other is to put ESP into flash mode when you use conventional USB2UART programmer. We have reused one NodeMCU to make a lot more convenient programmer out of it, because it handles resets and flash mode boot automatically. Details will follow.

What is expected cost?

We have designed swifitch to be both cheap and safe. So it is not ultra cheap but not expensive too. Our cost calculations has stoped at $8! Not bad, what you think?

How does it look like?

Definitely beautiful!!

How big is it?

Actually very small, you should be able to fit it almost anywhere without any hassle. But I know, numbers tell it all, so here it is.

Width	Height	Depth	Weight W/O BOX	Weight W/ BOX
42mm / 1.65"	60.5mm / 2.36"	19.6mm / 0.77"	~42g / ~1.48oz	~72g / ~2.54oz

Is it safe?

We have designed few safety features in swifitch. Most important are fuses on mains input. There is one overcurrent fuse and one overvoltage fuse (surge protection), and more importantly temperature fuse that will disconnect swifitch from mains input when temperature raises above 100°C. There should be another few safeties in HLK-PM01 but we didn't want to depend on it's quality.

OK I'm sold! What do I need to build it?

Capacitors

Preview	Part	Buy
	4.7μF 0805
	100nF 0805
	10nF 0805
	47μF ⌀6.3x5mm
	47nF X2

Resistors

Preview	Part	Buy
	10kΩ 0805
	1.5kΩ 0805
	2.2kΩ 0805
	47kΩ 0805
	160Ω 1206
	S10K275

Power and Controls

Preview	Part	Buy
	SCHURTER MST 250VAC 500mA
	PROFFUSE TZ-P100/2 100°C or similar
	Hi-Link HLK-PM01 AC-DC 5V/3W
	SRD-05VDC-SL-C Relay FINDER 36.11.9.005.4011

Other SMD Parts

Preview	Part	Buy
	BC817-16.215
	BAS86
	MCP1825T-3302E/DC Voltage Regulator
	Ferrite Bead 600Ω 100MHz 0805
	Any 0805 LED diode

Connectors

Preview	Part	Buy
	Headers 1x2 2.54mm pitch
	Headers 2x5 2.54mm pitch
	Terminal 2P and 3P, 5.08mm pitch rounded lead

The rest

Preview	Part	Buy
	ESP8266-12(E/F/S)
	PCB

Most of it could be purchased on AliExpress or eBay for what we call "no money", some parts are safer to get from your local trusted electricians shop (fuse and relay if you do not want chinese).

Most AliExpress links in table above are tested and trusted sellers, but we do not give any guarantees.

TME.eu is good source for EU citizens and especially guys in Czech Republic.

Farnell should be OK for all over world.

SeeedStudio Fusion PCB

How to order PCBs

First grab gerber files ZIP and upload it to SeeedStudio Fusion PCB then follow instructions below.

We have created sreenshots from ordering process so you can recreate the process in same manner. Decide how many pieces you want and get started. Keep in mind that each board are actually two swifitches ;). That makes it even cheaper.

Gerber files preview:

After you build it

OK DONE! What's next?

Now you need to flash some software to it. Either use conventional CP2102 USB2UART programmer or build your own as we did from NodeMCU, it is definitely best option you have.

This image tell you all you need to know but basically this is the list of steps:

• Desolder ESP8266 from NodeMCU (Heatgun baby!! But carefully you can use it for swifitch then.)
• Solder colored wires to the contacts according to image below
• Insert these wires to 2x5, 2.54mm pitch connector
• Connect to swifitch and flash firmware

We have created software for you to get started quicky so go to it's own repository.

⚡ DO NOT CONNECT SWIFITCH TO MAINS VOLTAGE WHEN FLASHING ⚡

It should be safe, but we do not recommend it!

Software

Swifitch default software

If you went with our software you are good to go, just follow the README in the repository.

Custom software

Just few things you need to know if you develop your own software.

• Relay is controled by D1 or GPIO5 PIN
• Built in LED is controled by D6 or GPIO12 PIN

Enclosure

3D Printed

If you have access to 3D printer, have a look at our original swifitch box.

If you wish to design your own box and you use Fusion 360, here is 3D model of Swifitch.

Use ABS plastic filament as this device is using mains voltage and ABS is safer for such devices.

DO NOT USE CONDUCTIVE FILAMENTS

Purchased ABS box

We have fitted swifitch to box that can be purchased from various electrical shops. May not be available in all countries thought.

Soldering cheatsheet

Back side

Start with SMD parts on the BACK side.

Capacitors

Slot	Part
C1	4.7μF
C3	4.7μF
C5	4.7μF
C6	4.7μF
C4	100nF
C7	100nF
C8	10nF

Resistors

Slot	Part
R3	10kΩ
R4	10kΩ
R5	10kΩ
R6	10kΩ
R7	10kΩ
R8	2.2kΩ
R9	47kΩ
R10	160Ω
R11	160Ω

The rest

Slot	Part
FB1	FB 600Ω 100MHz
D1	BAS86
T1	BC817
WiFi1	ESP8266-12(E/F/S)

Front side

Front side contains mostly THT parts, but start with SMD parts that would be harder to solder when you finish all bigger parts.

SMD

Slot	Part
R1	470Ω < Rled < 2kΩ (depends on LED1)
LED1	Choose color you like
V1	Voltage Regulator

THT

Slot	Part
DC1	HLK-PM01
F2	100°C fuse
R2	S10K275
F1	MST250/0.5A
C10	47nF
C2	47μF
C9	47μF
SB1	Optionaly enable D5 or 5V
JP1	1x2 header
JP2	1x2 header
J3	2x5 header
RE1	Relay
J1	2P terminal
J2	3P terminal

🎉 DONE 🎉

Credits

• PCB design, electronics ideas, parts selection - Miroslav Batěk
• SW, Git Repo, design, 3D printed enclosure - Martin Doubek

Mentions

Yellow Couch

Czech - with English subtitles

What's next?

If you liked swifitch and want to submerge deeper into IoT we will reference some other projects here.

• tjclement's ESP8266 dimmer HW for LED Strips

IoT platforms and enablers.

• Homebridge - HomeKit server
  • Homebridge MQTT plugin
• Blynk - platform and applications for IoT - Swifitch is supported
• Soldering timelapse from one of our builders - YouTube

Photos