Emergency Button for 7$, Arduino, WIFI and ESP8266
404.Emergency Button for 7$, Arduino, WIFI and ESP8266 There are many projects going on right now that aim to help older people stay more independent. Since my friend's grandmother is 95…
Know the mission before touching a wire.
Understand what you are making, prepare the right tools, and make the workbench safe.
Project details
Emergency Button for 7$, Arduino, WIFI and ESP8266 is a iot project. 404.Emergency Button for 7$, Arduino, WIFI and ESP8266 There are many projects going on right now that aim to help older people stay more independent. Since my friend's grandmother is 95…
- Source pages
- 919-924
- Named parts
- 7
- Build goal
- Working, tested prototype
Tools you need
- Digital multimeter
- Wire stripper and side cutters
- Soldering iron with a fine tip
- Current-limited bench supply
- Computer with a data-capable USB cable
Use eye protection, good lighting, and a clean insulated surface throughout the build.
Safety precautions
- Disconnect every power source before changing a connection.
- Check component polarity, pinout, and supply voltage twice.
- Use a current limit for the first power-up.
- Keep liquids, loose metal, and uninsulated wires away from the bench.
Gather, identify, and understand every part.
Use the standardized inventory, then open What's this? to learn each part's role, advantages, limitations, handling, and specifications.
What's this?Image, role, pros, cons, handling & specifications
"pushbutton 12*12*8cm."
A named project component whose exact role is defined by the source circuit and build guide.
What it does hereIt performs a documented electrical, control, interface, or construction function in this project.
Buy / compare this part ↗Advantages
- Selected for this project
- Can be checked independently
- Supports modular troubleshooting
Limitations
- Substitutes may differ
- Generic names can hide variants
- Pinouts and ratings vary
Handling
- Compare the received part with the source
- Keep it labelled
- Do not force connectors or adjusters
Specifications to verify
- Use the exact model, value, package, and rating listed for "pushbutton 12*12*8cm."; similar-looking parts are not always interchangeable.
- Confirm dimensions, ratings, connection method, polarity, and environmental limits.
What's this?Image, role, pros, cons, handling & specifications
V regulator
A power component supplies, converts, stores, or regulates energy for the project.
What it does hereIt must provide the documented voltage, polarity, isolation, and sufficient current safely.
Buy / compare this part ↗Advantages
- Stable power improves reliability
- Current limiting protects first tests
- Regulation reduces resets and noise
Limitations
- Wrong polarity can cause immediate damage
- Underrated parts overheat
- Mains circuits require qualified supervision
Handling
- Measure output before connection
- Use a fuse or current limit
- Insulate exposed conductors
Specifications to verify
- Use the exact model, value, package, and rating listed for V regulator; similar-looking parts are not always interchangeable.
- Confirm input/output voltage, current, polarity, connector, isolation, and thermal rating.
What's this?Image, role, pros, cons, handling & specifications
Male Header (angle or straight)
A named project component whose exact role is defined by the source circuit and build guide.
What it does hereIt performs a documented electrical, control, interface, or construction function in this project.
Buy / compare this part ↗Advantages
- Selected for this project
- Can be checked independently
- Supports modular troubleshooting
Limitations
- Substitutes may differ
- Generic names can hide variants
- Pinouts and ratings vary
Handling
- Compare the received part with the source
- Keep it labelled
- Do not force connectors or adjusters
Specifications to verify
- Use the exact model, value, package, and rating listed for Male Header (angle or straight); similar-looking parts are not always interchangeable.
- Confirm dimensions, ratings, connection method, polarity, and environmental limits.
What's this?Image, role, pros, cons, handling & specifications
Capacitor 10uF Female Header and a few resistors
A passive component sets current, voltage, timing, filtering, or signal behaviour without adding gain.
What it does hereIts exact value and tolerance determine how the surrounding stage behaves.
Buy / compare this part ↗Advantages
- Simple and dependable
- Low cost
- Easy to measure before installation
Limitations
- A wrong value can stop or damage the circuit
- Ratings must not be exceeded
- Polarized parts require correct orientation
Handling
- Measure unclear values
- Observe capacitor polarity
- Avoid overheating leads while soldering
Specifications to verify
- Use the exact model, value, package, and rating listed for Capacitor 10uF Female Header and a few resistors; similar-looking parts are not always interchangeable.
- Confirm value, tolerance, power or voltage rating, polarity, and package size.
What's this?Image, role, pros, cons, handling & specifications
Connector for battery on proto board
A power component supplies, converts, stores, or regulates energy for the project.
What it does hereIt must provide the documented voltage, polarity, isolation, and sufficient current safely.
Buy / compare this part ↗Advantages
- Stable power improves reliability
- Current limiting protects first tests
- Regulation reduces resets and noise
Limitations
- Wrong polarity can cause immediate damage
- Underrated parts overheat
- Mains circuits require qualified supervision
Handling
- Measure output before connection
- Use a fuse or current limit
- Insulate exposed conductors
Specifications to verify
- Use the exact model, value, package, and rating listed for Connector for battery on proto board; similar-looking parts are not always interchangeable.
- Confirm input/output voltage, current, polarity, connector, isolation, and thermal rating.
What's this?Image, role, pros, cons, handling & specifications
ESP8266 - controller board / IC
A programmable controller that reads inputs, makes decisions, and drives the project's outputs.
What it does hereIt is the control centre and must use the documented board, pin map, supply, and logic level.
Buy / compare this part ↗Advantages
- Reprogrammable and reusable
- Large learning ecosystem
- Complex behaviour remains changeable
Limitations
- GPIO voltage and current are limited
- Some pins affect boot or communication
- Loads normally need a driver
Handling
- Disconnect power before rewiring
- Avoid static discharge
- Never power motors, relays, or pumps directly from GPIO
Specifications to verify
- Use the exact model, value, package, and rating listed for ESP8266 - controller board / IC; similar-looking parts are not always interchangeable.
- Confirm operating voltage, logic level, pinout, memory, USB interface, and maximum GPIO current.
What's this?Image, role, pros, cons, handling & specifications
ATMEGA328P - controller board / IC
A programmable controller that reads inputs, makes decisions, and drives the project's outputs.
What it does hereIt is the control centre and must use the documented board, pin map, supply, and logic level.
Buy / compare this part ↗Advantages
- Reprogrammable and reusable
- Large learning ecosystem
- Complex behaviour remains changeable
Limitations
- GPIO voltage and current are limited
- Some pins affect boot or communication
- Loads normally need a driver
Handling
- Disconnect power before rewiring
- Avoid static discharge
- Never power motors, relays, or pumps directly from GPIO
Specifications to verify
- Use the exact model, value, package, and rating listed for ATMEGA328P - controller board / IC; similar-looking parts are not always interchangeable.
- Confirm operating voltage, logic level, pinout, memory, USB interface, and maximum GPIO current.
Connect one verified path at a time.
Explore the named components and standardized signal flow, then use Source Check to verify exact physical pins, values, and topology before applying power.
Trace this circuit.
Emergency Button for 7$, Arduino, WIFI and ESP8266: interactive parts, standardized terminals, responsive anchored wires, student explanations, and the original circuit reference in one shared system.
Trace before wiring
Follow power, ground, inputs, processing, and outputs in that order. Never guess a pin from package shape alone.
Connect with power off
Make short, labelled connections and share a common ground only where the schematic requires it.
Inspect every joint
Check continuity, polarity, adjacent shorts, and loose connections before the first power-up.
Open all source diagrams and build views 3 visuals
Prepare, upload, and verify the program.
Follow the same software sequence every time: verify connections, prepare the toolchain, compile, and upload.
How to connect
- Match every controller label to the circuit view and source pin map.
- Join grounds before signal wires when separate low-voltage supplies are used.
- Keep motors, relays, pumps, and other loads on a suitable driver and external supply.
Common mistakes
Reversed VCC/GND, board-label versus GPIO-number confusion, missing common ground, and charge-only USB cables.
Troubleshoot
Disconnect loads, continuity-test one path at a time, then test with a current limit.
Software preparation
- Install the current Arduino IDE or the software named in the guide.
- Install the correct board package and required libraries.
- Select the exact board, processor, and serial port.
- Compile once before connecting external loads.
How to upload code
- Connect the board with a data-capable USB cable.
- Open the documented sketch and confirm configuration values.
- Compile, fix the first reported error, and upload.
- Test with external loads disconnected first.
Common mistakes
Wrong port, missing library, incorrect board selection, boot pins held in the wrong state, or a busy serial port.
Your ESP8266 board can be programmed in many ways
A Serial to USB converter like the FTDI FT232RL is the most important
thing you need to programme. One can be found in a special device like an
FTDI board, but every Arduino Board that can be programmed over USB
also has one (On the UNO the FTDI has been replaced by a 32u2, but it
worked exactly the same). For example, if you have a UNO board, you can
reprogram the ESP8266 by taking out the microcontroller and using the RX,
TX, GND, and 3.3V pins. The Arduino board must, of course, have a chip
that can be taken out...
The second important thing to remember is that you have to change the
GPIO 0 Pin to be able to programme (Ground state) and use it (3.3V state).
It can be a little confusing because the new device code starts running
automatically after programming, even if GPIO 0 is still grounded. But if
you restart the programme, you have to make sure that GPIO 0 is at 3.3V or
it won't work. So, you can programme your ESP with a few wires and an
Arduino UNO. But if you programme the board a lot, this method can be a
pain because you don't know if the problem is in the hardware or the
software when it doesn't work or when you need to add more parts. So you
spend a lot of time making sure no wire got unplugged or plugged in the
wrong place. I made a prototype board because of this.
Installing the Arduino IDE for the ESP8266 is the first thing to do. Now that
we have the board's programmer, we need to look at the software. The
device needs to connect to a WiFi network and use SMTP to send an email.
As SMTP isn't accepted by GMAIL and many other mail servers, I used an
SMTP2GO server as a middleman. So the device sends an email to
SMTP2GO, which then sends it to your email account. Setting up an account
on SMTP2GO is free and doesn't take long.
As this project connects to the Internet through Wifi and needs to send
email, we have to change a few lines of code for each app. In this case, it
will be everywhere that has someAssemble, deploy, test, and troubleshoot.
Use the complete source notes in build order, then pass the final checks before calling the project finished.
Build in functional stages
- Power and regulation
- Controller or processing stage
- Inputs and sensors
- Outputs and loads
- Enclosure and strain relief
Power up safely
- Inspect unpowered continuity first
- Apply the lowest safe current limit
- Measure supply rails before signals
- Add one load at a time
- Record expected and actual results
Work from simple to complex
- Confirm power, ground, polarity, and orientation
- Compare each pin with the source
- Test inputs separately from outputs
- Replace only one variable at a time
- Power off before every correction
Follow the documented instructions.
These notes come from this project's source and remain in their original order.
Project overview
Project build note404.Emergency Button for 7$, Arduino, WIFI and ESP8266
There are many projects going on right now that aim to help older people stay more independent. Since my friend's grandmother is 95 years old and still lives alone in her apartment, I wanted to see what I could do to help her stay there as long as possible. One of the hardest things for old people to do when walking is to keep their balance. It's getting harder and harder to move around, and if they fall down, it's hard to get back up. My family calls my grandmother every night to see if something like this is going on. There are some emergency buttons that can help, but the call center usually costs a lot each month. Also, most older people don't like wearing grey plastic gadgets around their necks. Most apartments today have 10 or 20 WiFi connections that are easy to reach. So I decided to build a device that could connect to WiFi and make it easy to talk to the outside world. Since many older people don't have WiFi, I decided to ask the neighbors if I could use theirs. Most of them were happy to help and even asked to have their email address added to the list so they could help quickly in an emergency. If someone is in trouble, all they have to do is push a simple button on the device. An LED lights up to show that the emergency is on. The device will connect to the internet box and send an email to an email address that has
already been entered. As many people (like me) get email on their phones and check them 30 times a day, the emergency can be handled quickly by calling the person or knocking on the door. The device has to be simple to put on and work with. So, it was important to drastically cut down on the size and weight. So, the device is 2.5 x 1.5 x 1 cm (1 x 0.6 x 0.4 inches) in size, which makes it easy to add to bracelets, necklaces, or clothing. The button is big because some older people shake a lot, which makes it easier to press. A very important question is also the price. The ESP8266 board is a great choice if you want to make a WiFi-connected device right now. It only costs a few dollars and has its own 32-bit microcontroller that can be changed (The Atmega328p on the Arduino UNO is only 8bits). This device is now used by a large group of people, and it recently became compatible with the Arduino IDE.
Most people can afford to pay about $8 for the electronics, and you just have to add a battery of your choice. If you want to make your own design, it's easy to find and change any of the parts. A standard 110 mA battery should last more than 2 months, a CR2032 battery should last 5 months, and a 1000 mA battery should last 2 years. I used the cheapest and smallest parts I could find for this project. The ESP8266 is a great tool for any microcontroller/WiFi application today. Plus, it now works with Arduino! As I was adding code to the ESP8266 100 times a day, I decided to also make a programmer that was easy to use. If you don't want to change a lot of things in the code, you don't really need it.
Components Required
Project build noteESP8266, which costs $7, comes with WiFi and an antenna for WiFi. Button: $0.50. Pick the one that fits your model best. I used a "pushbutton 12*12*8cm."
LED 0.35$
Project build noteThe price of a resistor is $0.02 (I used a flat top 3mm bought on Ebay) Battery is $6.95 In a bigger device, you could use a CR2032 to make it last 2.3 times longer, or this bigger battery to make it last 9 times longer. Account SMTP2GO is free. It sends mail from the device to your mail account (the Free version is limited to 20 mails a day). FREE Email Address. With this code, I used a GMAIL one. You'll need a few wires and the following to programme your
device
Project build noteFTDI basic board and a 3.3V (minimum 500 mA) power supply or
A chip can be taken out of the UNO-style Arduino board, but not the SMD version. In the second part of this Instructable, I show how to make a programmer that can be counted on. If you want to build it, you need
to add the following parts
Project build note3.3V regulator Male Header (angle or straight) Capacitor 10uF Female Header and a few resistors Connector for battery on proto board
You built Emergency Button for 7$, Arduino, WIFI and ESP8266.
You followed the full workflow from understanding the mission to testing the finished project. That is a real engineering achievement - well done.
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