Trigger Your DSLR Wirelessly With Smartphone and ESP8266 Wi-fi Module

This is my first instructable, and English is not my native language, so be lenient (but I would be grateful to anyone pointing out misspellings, typos... ;) ).

It will only cost you a few bucks (pounds, euros or whatever) and require basic soldering skills to wirelessly trigger your DSLR camera from any smartphone, including Self-timer and Intervalometer modes.

I tested it with a Canon DSLR, but it should work with any camera with built-in shutter switch terminal (cf. http://www.doc-diy.net/photo/remote_pinout/)

During this instructable, I will mostly focus on steps where I have some added value, and just give pointers when good informations already exists on the Net.

Precisely, here are some interesting links before I get into the main topic:

About the different ways to trigger a remote camera
https://www.instructables.com/id/Automatic-Camera-Shutter-Switch/
All you need to know about remote control for Canon EOS cameras
http://www.doc-diy.net/photo/eos_wired_remote/
Great tutorial with excellent explanations of optocouplers
http://www.martyncurrey.com/activating-the-shutter-release/

Actually, it was this last tutorial that made me want to get into this project...

Step 1: Shopping List

ESP8266 Wi-fi module
USB to serial adapter, with Dupont cables
battery AAA x 2
battery holder
switch
optocoupler 4N25 or equivalent
resistor 220 Ohm (actual value depends on optocoupler characteristics)
small scrap of prototyping board
tablets tube (nice enclosure :) )
cable and connector, depending on your camera model

Step 2: About ESP8266...

ESP8266 is a small and very cheap Wi-fi module (with embedded MCU) that comes in many flavors.

For this instructable, I used ESP-01, which is the most common reference.

I got mine directly from China for less than 3€ (Banggood) but if you are not willing to wait two weeks for delivery, google for ESP8266 and you will find many local resellers.

I will not dwell on ESP8266 because many excellent tutorials already exist, describing how to torture this cute little device any possible way.

The only important point concerns NodeMCU firmware, which must be installed in place of the default firmware (aka "AT firmware") coming with ESP8266.

Here are some pointers to useful information about ESP8266:

Technical overview
https://nurdspace.nl/ESP8266
General presentations
http://benlo.com/esp8266/esp8266QuickStart.html
https://www.openhomeautomation.net/getting-started-esp8266/
http://www.labradoc.com/i/follower/p/notes-esp8266
ESP community forum
http://www.esp8266.com/
Open-source alternative firmware (brings Lua scripting to ESP8266)
http://nodemcu.com/index_en.html
Integrated Development Environment (IDE) for ESP8266 developers
http://esp8266.ru/esplorer/

Step 3: NodeMCU Installation

Download a recent release of NodeMCU from https://github.com/nodemcu/nodemcu-firmware/releases (for this project, I used nodemcu_integer_0.9.6-dev_20150406) and follow one of these tutorials, depending on your OS:

As an alternative, Windows users can use this ESP flasher:

http://www.xess.com/blog/esp8266-reflash/ (just replace AT firmware by NodeMCU firmware)

Step 4: Lua Scripts Installation

Now that NodeMCU is running, you'll have to feed your ESP8266 with appropriate Lua scripts, available at https://github.com/CosmicMac/ESP8266-remote

Download these 5 files:

index.html
favicon.png
filesend.lua
init.lua
server.lua

and upload them to ESP using ESPlorer tool (you need JAVA installed on your computer).

Connect ESP8266 to your "USB to serial" adapter, and adapter to your computer
Download ESPlorer
Unzip the archive and open ESPlorer folder
Run ESPlorer.bat (Windows users) or ESPlorer.jar
You should see a window similar to above figure
Select your adapter port, 9600 baud rate and press Open
Wait for Cannot open init.lua message and press Upload... to upload each of the 5 files to ESP
Stay connected but change baud rate to 115200
Press Reset
Wait for Server ready! message

Your ESP module is now ready to get tested (preferably before making the wiring).

You just have to follow instructions from the "Use it" step and check feedback on the terminal screen.

Step 5: Let's Do It...

Wire the parts as on the schematic above.

Because you will sometimes want to modify ESP scripts or firmware, it's preferable to use cables with Dupont connectors rather than directly solder ESP pins.

4N25 optocoupler wiring details:

pin 1 to VCC throught resistor
pin 2 to ESP GPIO0
pin 4 to ground wire of the release cable
pin 5 to shutter wire of the release cable

Step 6: ... and Use It

Turn your freshly made ESP remote module on, connect it to you camera, get your favorite smartphone ready, and follow each simple step bellow:

Turn Wi-fi on
Connect to access-point named ESP (password: 12345678)
Point your browser to IP adress 10.10.10.10
You should see a web page similar to screen shot above
Press Trigger and enjoy the delicate sound of your camera shutter... :)

You can now play with Self-timer and Intevalometer settings.

The Sound option is intended as an audio feedback for Self-timer, but doesn't seem to work with Android Chrome.
If you feel like needing this nice option, just install Firefox.
Unfortunately, neither Vibration nor Sound seem to work with Safari...

Well... This is this end of my first instructable.
I hope you'll appreciate it and I'm looking forward to your feedback.

Happy remote triggering!

Stay tuned!

My next instructable will introduce my wireless camera trap, based on ESP8266 (what else?) coupled with a PIR sensor.
Oh, and if you don't feel like waiting for it, have a look at https://github.com/CosmicMac/ESP8266-trap

Introduction: Trigger Your DSLR Wirelessly With Smartphone and ESP8266 Wi-fi Module