Albert: ESP8266

Showing posts with label ESP8266. Show all posts

Thursday, June 22, 2023

Rugged Metal Buttons with LED Rings on Raspberry Pi

How to interface rugged metal pushbuttons with LED rings to a headless Raspberry Pi — using the built-in triggerhappy daemon to invoke scripts on button press and provide LED feedback, with no display or keyboard needed.

Connection diagram — pushbuttons to Raspberry Pi GPIO

Connection diagram — two pushbuttons wired to Raspberry Pi GPIO pins.

How it works

Instead of userspace I/O libraries, this approach uses the triggerhappy daemon (built into Raspbian) to map standard key codes from /dev/input/eventX to scripts via /etc/triggerhappy/triggers.d/actions.conf.

Overview of the steps:

Connect pushbuttons to Raspberry Pi GPIOs as shown in the connection diagram
Prepare a Raspberry Pi OS Lite SD card using Raspberry Pi Imager
SSH into the Raspberry Pi
Add dtoverlay config lines to /boot/config
Create push-buttons.conf under /etc/triggerhappy/triggers.d/
Modify /lib/systemd/system/triggerhappy.service to run as the pi user
Create action scripts configured in push-buttons.conf
Reboot and press a button to see the configured action invoked

Prepare the SD card

Download the Raspberry Pi Imager
Open the app → CHOOSE OS → Raspberry Pi OS (Other) → Raspberry Pi OS Lite (32-bit)
Insert the SD card and click CHOOSE STORAGE
Press Ctrl + Shift + X to open advanced options
Set hostname, enable SSH, username/password, and local time settings as shown below, then click SAVE
Click WRITE to create the bootable SD card

Raspberry Pi Imager — advanced options for headless setup.

Setup and demo

Connect two pushbuttons to Raspberry Pi GPIO pins as shown in the connection diagram
Insert the SD card, connect the Pi to your local DHCP network, and power on
SSH in: ssh pi@my-raspi-001 (use the password from the Imager advanced options)
Run the following commands:

sudo apt-get install -y git esptool
git clone https://github.com/hackboxguy/pi-pushbtn-demo.git
cd pi-pushbtn-demo
sudo ./setup.sh
sudo reboot

Running the setup commands on the Raspberry Pi.

Wait ~40 seconds for the Pi to reboot. Press one pushbutton — its LED ring blinks at ~2 Hz. Press the other button — its LED starts blinking and the first one stops.

Extending the demo

Instead of just blinking LEDs, the buttons can invoke real tasks. For example, to flash different firmware binaries to an ESP8266 (e.g. Wemos D1 Mini) on button press, replace the action scripts:

cp /home/pi/pi-pushbtn-demo/flash-esp-1hz.sh /home/pi/pi-pushbtn-demo/key-pressed-down.sh
cp /home/pi/pi-pushbtn-demo/flash-esp-4hz.sh /home/pi/pi-pushbtn-demo/key-pressed-up.sh

After this change, pressing a button blinks the LED ring for ~30 seconds (indicating the Wemos D1 Mini is being flashed), then stops when flashing completes. See the 1 Hz flash script and 4 Hz flash script for details.

Hardware setup — pushbuttons connected to Raspberry Pi

Complete setup — rugged metal pushbuttons connected to the Raspberry Pi.

SOURCE CODE

github.com/hackboxguy/pi-pushbtn-demo — scripts and setup instructions

Thursday, January 03, 2019

Wi-Fi LED Fairy Light Controller with ESP8266

A DIY Wi-Fi-controlled 5 V switcher for USB LED fairy lights, built around an ESP-12F module running Tasmota firmware. Powered by a battery bank, it lets you toggle garden lights remotely from your phone — no 230 V wiring outdoors and no freezing walks to the power outlet.

The lights

"USB Fairy Lights" or "USB String Lights" — 10 m / 100 LEDs, available from China for under ~$3. They are 5 V USB-powered and weather-proof (except the USB connector).

The 100-LED circuit with 5.1 Ohm series resistor — consumes ~1.8 W at 5 V.

Close-up of a single LED — brightness difference between first and last LED is barely noticeable from a distance.

The ESP-12F 5 V switcher

An ESP-12F module with a MOSFET switches the USB 5 V supply to the LED string. Running Tasmota firmware, it connects to your Wi-Fi network and can be controlled from a phone or any MQTT/HTTP client.

Complete setup — battery bank, ESP switcher, and LED string

Complete setup — battery bank, ESP-12F switcher, and LED fairy lights.

With Tasmota's default configuration (no deep sleep), the battery bank needs recharging every few days. A larger battery and ESP8266 deep sleep could extend runtime to weeks.

Assembly

Before starting, ensure the ESP-12F module is pre-programmed with Tasmota (or any OTA-capable firmware). See ESP-12F programming guide for first-time flashing.

Items needed:

Step 1:

Step 2:

Step 3:

Step 4:

Step 5:

Step 6:

Step 7:

Step 8:

Step 9:

Final assembly:

Switcher connected to battery bank and LED string

Completed setup — ESP-12F switcher between battery bank and LED fairy lights.

Sunday, December 30, 2018

Build a $2 IoT/MQTT Node with a Bare ESP-12F

How to use a bare ESP-12F module as a standalone IoT/MQTT node — powered directly from a USB charger with just a handful of passive components, no base board required. Total cost: under $2.

Finished board — ESP-12F module with USB connector, ready to plug into any 5V charger.

Items needed

Prices based on AliExpress at the time of writing:

1x ESP-12F module (pre-programmed with Tasmota firmware)
1x 10k SMD resistor
1x 10k through-hole resistor
2x 4001 SMD diode
1x USB male connector (PCB mount, SMD)

Schematic

Wiring diagram — USB 5V stepped down through two diodes to ~3.6V for the ESP-12F.

Board preparation

Step 1 — Ensure the ESP-12F module is programmed with Tasmota firmware. See the ESP-12F programming post for details.

Step 2 — Mount a 10k SMD resistor between the GND and IO15 pads of the ESP-12F module.

10k SMD resistor soldered between GND and IO15 pads.

Step 3 — Mount a 10k through-hole resistor between the VCC and EN pads of the ESP-12F module.

10k through-hole resistor between VCC and EN

10k through-hole resistor connecting VCC to EN (chip enable).

Another angle showing the VCC–EN pull-up resistor.

Step 4 — Stick a piece of insulation tape on the right side of the ESP-12F module so the USB connector doesn't short any pads.

Insulation tape prevents shorts between the USB connector and ESP pads.

Step 5 — Place the USB connector as shown below. The SMD pins of the USB connector should sit over the insulation tape.

USB connector positioned over the insulation tape.

Step 6 — On the back side, fix the USB connector to the ESP-12F using hot glue. Don't apply hot glue on the SMD pin side yet — that comes later.

Hot glue fixing USB connector on back side

Hot glue secures the USB connector on the back side.

Step 7 — Solder two SMD diodes in series between the + line of the USB connector and the VCC pad of the ESP-12F module.

Two SMD diodes in series for voltage drop

Two 4001 diodes in series drop 5V USB to ~3.6V for the ESP-12F.

Step 8 — Connect the − line of the USB connector to the GND pad of the ESP-12F module.

USB ground connected to the ESP-12F GND pad.

Step 9 — Apply hot glue on both sides of the USB connector and ESP-12F for stability.

Hot glue on both sides for mechanical strength.

Completed board — ready for testing.

Testing

Step 10 — Power the board with a 5V USB charger and look for an open Wi-Fi SSID named sonoff-NNNN.

Step 11 — Connect to the SSID and follow the standard Tasmota generic module configuration.

Your $2 IoT/MQTT node is ready. Plug it into any USB charger, configure Tasmota to connect to your MQTT broker, and start automating.

Pogo-Pin Programming Dock for ESP-12F Modules

How to convert a Wemos D1 Mini into a pogo-pin programming dock for flashing Tasmota (or any firmware) onto bare ESP-12F modules — no breadboard wiring needed.

Completed pogo-pin dock — a modified Wemos D1 Mini ready to flash ESP-12F modules.

Why?

ESP8266-based IoT modules can be purchased from AliExpress for as low as 1.3 EUR. These cheap Wi-Fi modules are handy for many home automation DIY projects, especially when used with open-source firmware like Tasmota. But programming bare ESP-12F modules requires connecting 8 pins — tedious on a breadboard and error-prone with dupont wires.

A pogo-pin dock lets you drop in a module, clip it down, and flash — repeatable and reliable.

Items needed

Everything you need to build the programming dock.

Wemos D1 Mini board
8 pogo pins
ESP-12F module
USB-to-Micro-USB cable
Clip for holding the ESP module on the pogo-pin dock

Preparation

Step 1 — De-solder the existing ESP module from the Wemos D1 Mini board. This is the most difficult part — you need good soldering skills.

Wemos D1 Mini after removing the original ESP module.

Step 2 — Carefully solder 8 pogo pins onto the exposed ESP pads on the Wemos D1 Mini: TXD0, RXD0, IO0, IO15, GND, VCC, EN, RST.

Pogo pins soldered onto the exposed ESP pads.

Step 3 — Place a fresh ESP-12F module on the newly prepared dock and secure it with a clip.

ESP-12F module placed on the pogo-pin dock

ESP-12F seated on the pogo-pin dock, ready for flashing.

Clip holds the ESP-12F firmly against the pogo pins during programming.

Flashing firmware

Step 4 — On your Linux host PC, clone esptool and download the Tasmota firmware:

cd ~
git clone https://github.com/espressif/esptool
cd esptool
wget http://thehackbox.org/tasmota/release/sonoff.bin

Step 5 — Connect the USB cable between your host PC and the Wemos D1 dock. Erase the ESP-12F flash:

./esptool.py --port /dev/ttyUSB0 erase_flash

Step 6 — Disconnect and reconnect the USB cable, then flash the Tasmota firmware:

./esptool.py --port /dev/ttyUSB0 write_flash -fs 1MB -fm dout 0x0 sonoff.bin

Your ESP-12F module is now flashed and ready for use. Check the next post about using an ESP-12F as a standalone board for home automation projects.

Close-up of pogo pins contacting ESP-12F pads

Close-up showing the pogo pins making contact with the ESP-12F module pads.

Another angle of the completed pogo-pin programming dock.