Generic2
Specifications
- Chip: WS2812B (built-in LED)
- LED: 5050 package RGB full-color highlight
- Voltage: 5V
- Port: digital
Main features
●The IC control circuit and the LED point light source share a power supply.
The control circuit and the RGB chip are integrated in a 5050 package component to form a complete externally controlled pixel point.
·Built-in signal shaping circuit, any pixel point receives the signal and then outputs it after waveform shaping, ensuring that the line waveform distortion will not accumulate.
●Built-in power-on reset and power-off reset circuits.
●The three primary colors of each pixel point can achieve 256 levels of brightness display, and complete the full-color display of 16777216 colors.
●Port scanning frequency 2KHz/S
Serial cascade interface, which can complete data reception and decoding through a signal line,
·No need to add any circuit when the transmission distance between any two points does not exceed 5 meters.
●When the refresh rate is 30 frames/second, the number of cascades is not less than 1024
Main application areas
●LED full-color luminous character light string, LED full-color soft light bar hard light bar, LED guardrail.
●LED point light source, LED pixel screen, LED special-shaped screen, various electronic products, electrical equipment marquee.
What's in the box?
1 x WS2812 LED 5050 RGB 8x8 LED Matrix board
Proximity switch, also known as non-contact proximity switch, is the ideal electronic switch sensor. Used for detecting metal in proximity. It does not require any contact or pressure. It will accurately reflect the position of a moving mechanism. The proximity switch is easy to install, adjustable, and suitable for harsh environments.
Specifications
- Model : LJ12A3-4-Z/BX
- Operating Voltage : DC 6-36V
- Output Type : NPN
- Output Status : Normally Open
- Detection object : metal objects
- Detection distance : 4 mm
- Output Current : 300 mA
- Response Frequency : 0.5KH
- Working temperature : Temperature range -30 ° to 60 °
- Dimensions : 12 mm screw diameter
- Cable length : about 115 cm
- Material : Metal and plastic
What's in the box?
1 x LJ12A3-4-Z/BX NPN Sensor Detection Switch
Resources
Brown - Live
Blue - Ground
Black - Signal
Diffused LEDs shine through a semi-transparent cover, absorbing the light and bouncing it through in different directions. Instead of seeing the individual LED light up, the whole bulb shines instead, giving a more uniform light spread over a greater area.
There are 5 colours of 5MM LEDs included. Red, Green, Yellow, Blue and White 200Pcs each with a total of 1000Pcs
Working current: 20 (mA)
Working voltage:
- Red: 2.0V-2.2V
- Yellow: 1.9V-2.1V
- Blue: 2.8V-3.0V
- Green: 3.0V-3.2V
- White: 3.2V-3.4V
What's in the box?
1000 x 5MM LED Diode
Resources
The 4-pin TCRT5000 module is significantly more versatile than the 3-pin version because it provides both a Digital Output (D0) and an Analog Output (A0).
The Digital pin is perfect for "Yes/No" detection (like staying on a line), while the Analog pin allows you to see the intensity of the reflection, which is useful for measuring varying shades of gray or very small changes in distance.
Features
- Compatibility: Perfectly designed for Arduino projects, ensuring seamless integration and operation.
- Advanced Sensing: Utilizes IR technology with TCRT5000 sensors for accurate detection of reflective materials or barriers.
- Easy to Use: Simplified setup, suitable for beginners and professionals alike.
- Versatility: Ideal for a wide range of applications including line tracking robots, object detection, and automatic control systems.
- Optimized Design: Compact form factor for efficient performance.
Specifications
- Colour: Blue
- Material: ABS
Due to different batches, there may be differences in product printed text, which will not affect use.
What's in the box?
1 x Infrared Reflective Sensor
The 4-pin TCRT5000 module is significantly more versatile than the 3-pin version because it provides both a Digital Output (D0) and an Analog Output (A0).
The Digital pin is perfect for "Yes/No" detection (like staying on a line), while the Analog pin allows you to see the intensity of the reflection, which is useful for measuring varying shades of gray or very small changes in distance.
1. Hardware Connections (4-Pin Module)
| Module Pin | Raspberry Pi Pin | Physical Pin # | Function |
| VCC | 3.3V Power | Pin 1 | Power for the IR LED and comparator. |
| GND | Ground | Pin 6 | Common ground. |
| D0 | GPIO 17 | Pin 11 | Goes LOW when a reflection is detected. |
| A0 | See Note Below | — | Provides a voltage (0V to 3.3V) based on reflection. |
Important: The Raspberry Pi does not have a built-in Analog-to-Digital Converter (ADC). You cannot plug the A0 pin directly into a Pi GPIO and read its value. You have two choices:
- Ignore A0: Use only D0 for simple line following.
- Use an ADC Chip: Connect A0 to an MCP3008 chip if you need precise reflection data.
Python Code (gpiozero):
from gpiozero import DigitalInputDevice
from signal import pause
# TCRT5000 D0 is connected to GPIO 17
# pull_up=True because the sensor output is Active Low
sensor = DigitalInputDevice(17, pull_up=True)
def detected():
print("Reflection Detected! (LED on module should be lit)")
def cleared():
print("Reflection Lost.")
sensor.when_activated = detected
sensor.when_deactivated = cleared
print("Starting TCRT5000 Digital Test...")
pause()Wiring A0 through an ADC:
Connect A0 from the sensor to CH0 on the MCP3008.
Connect the MCP3008 to the Pi via the SPI pins (GPIO 8, 9, 10, 11).
Python Code (gpiozero with MCP3008):
from gpiozero import MCP3008
import time
# Create a reference to the Analog sensor on Channel 0 of the ADC
reflectivity = MCP3008(channel=0)
while True:
# Value will be between 0.0 (no reflection) and 1.0 (max reflection)
print(f"Reflection Intensity: {reflectivity.value:.2f}")
time.sleep(0.1)
Sensitivity Tuning: You can use the D0 pin for a fast interrupt-based response (like emergency stops) while simultaneously using A0 to log data or calibrate your robot's speed based on how well it sees the line.
Dual Monitoring: The onboard LED on the 4-pin module typically follows the D0 state. This makes it much easier to "sight in" your sensor by eye before you even write a single line of code.
Carbon dioxide is a critical indicator of indoor air quality that can affect human cognitive
abilities and well-being. The SCD40/SCD41 are Sensirion's next-generation miniaturized CO2 sensors, offering high precision and cost-effectiveness. These modules feature a 2.54mm pitch pin header interface for power supply and communication connections. On-chip temperature and humidity compensation is achieved through built-in sensors for humidity and temperature measurement. The SCD40/SCD41 can intelligently regulate indoor ventilation systems based on C02 concentration levels, thereby maintaining a healthy and efficient environment with low C02 levels over time. This makes the SCD40/SCD41 ideal for applications focused on improving indoor air quality.
Features
- 2.4-5.5V
- Detects CO2 Carbon Dioxide 400-2000ppm
- Detects Temperature
- Detects Humidity
- I2C Communication
Specifications
- Reference Accuracy and Range: SCD40: 400-2000 ppm
- Supply Voltage Range: 2.4-5.5 V
- High Accuracy: ±(40 ppm + 5%)
- Digital Interface: 12C
- Integrated Temperature and Humidity Sensor
- Low Power Consumption
- Typical Accuracy 50ppm +-5% reading
- Pin Definitions
GND: Ground input terminal
VDD: Positive power supply input terminal
SCL: 12C clock terminal
SDA: 12C data terminal
What's in the box?
1 x SCD40 sensor
Resources
The SCD40 and SCD41 are high-performance "True" CO2 sensors. Unlike cheaper VOC sensors that estimate CO2 levels, these use photoacoustic technology to measure the actual concentration of CO2 in the air.
The setup for the Raspberry Pi 5 (and older models) involves the I2C interface.
1. Hardware Connections (I2C)
The module communicates via I2C, which only requires four wires. Note that while these sensors can handle 5V power, the Raspberry Pi's logic pins are 3.3V. Ensure your module's I2C lines are compatible (most breakout boards from Adafruit/PiShop have 3.3V regulators/shifters built-in).
| Sensor Pin | Raspberry Pi Pin | Physical Pin # |
| VIN / VCC | 3.3V (or 5V if supported) | Pin 1 (3.3V) or Pin 2 (5V) |
| GND | Ground | Pin 6 |
| SCL | I2C Clock (GPIO 3) | Pin 5 |
| SDA | I2C Data (GPIO 2) | Pin 3 |
2. Enable I2C on the Raspberry Pi
Before you can read the data, you must enable the I2C port:
Run
sudo raspi-configin the terminal.Navigate to Interface Options > I2C.
Select Yes to enable it.
Reboot your Pi.
(Optional) Check if the sensor is detected by running
i2cdetect -y 1. The SCD4x should appear at address 0x62.
3. Install the Python Library
The easiest way to interact with the SCD4x in 2026 is via the Adafruit CircuitPython library, which is fully compatible with standard Raspberry Pi OS.
# It is recommended to use a virtual environment on the Pi 5mkdir co2_project && cd co2_projectpython3 -m venv .venvsource .venv/bin/activate# Install the librarypip3 install adafruit-circuitpython-scd4x
4. Python Example CodeThis script initializes the sensor and prints the CO2, Temperature, and Humidity readings every two seconds.
import timeimport boardimport adafruit_scd4x# Initialize I2C bus and sensori2c = board.I2C()scd4x = adafruit_scd4x.SCD4X(i2c)print("Serial number:", [hex(i) for i in scd4x.serial_number])# Start the sensor's internal measurement cyclescd4x.start_periodic_measurement()print("Waiting for first measurement (takes ~5 seconds)...")try: while True: if scd4x.data_ready: print(f"CO2: {scd4x.CO2} ppm") print(f"Temperature: {scd4x.temperature:.1f} °C") print(f"Humidity: {scd4x.relative_humidity:.1f} %") print("-" * 20) time.sleep(2)except KeyboardInterrupt: # Important: Stop measurements to save power/sensor life scd4x.stop_periodic_measurement() print("Measurements stopped.")
Key Differences for SCD41 UsersIf you specifically have the SCD41, you have a few extra features:
- Single Shot Mode: The SCD41 can take a single measurement and go back to sleep, which is better for battery-powered projects. The SCD40 must remain in "periodic" mode.
- Extended Range: The SCD41 reads up to 5,000 ppm (and even up to 40,000 ppm in "extended" mode), whereas the SCD40 is optimized for indoor air quality up to 2,000 ppm.
Pro Tips
If you are using this sensor for a commercial project in South Africa (like a school ventilation monitor), look into Automatic Self-Calibration (ASC). By default, these sensors calibrate themselves based on the lowest CO2 reading they see every week. If your room is never fully ventilated (never hits 400ppm), the sensor's readings will "drift." You can disable ASC in the code if you prefer to do a manual calibration outdoors.
Carbon dioxide is a critical indicator of indoor air quality that can affect human cognitive
abilities and well-being. The SCD40/SCD41 are Sensirion's next-generation miniaturized CO2 sensors, offering high precision and cost-effectiveness. These modules feature a 2.54mm pitch pin header interface for power supply and communication connections. On-chip temperature and humidity compensation is achieved through built-in sensors for humidity and temperature measurement. The SCD40/SCD41 can intelligently regulate indoor ventilation systems based on C02 concentration levels, thereby maintaining a healthy and efficient environment with low C02 levels over time. This makes the SCD40/SCD41 ideal for applications focused on improving indoor air quality.
Features
- 2.4-5.5V
- Detects CO2 Carbon Dioxide 400-5000ppm
- Detects Temperature
- Detects Humidity
- I2C Communication
Specifications
- Reference Accuracy and Range: SCD40: 400-5000 ppm
- Supply Voltage Range: 2.4-5.5 V
- High Accuracy: ±(40 ppm + 5%)
- Digital Interface: 12C
- Integrated Temperature and Humidity Sensor
- Low Power Consumption
- Typical Accuracy 50ppm +-5% reading
- Pin Definitions
GND: Ground input terminal
VDD: Positive power supply input terminal
SCL: 12C clock terminal
SDA: 12C data terminal
What's in the box?
1 x SCD41 sensor
Resources
The SCD40 and SCD41 are high-performance "True" CO2 sensors. Unlike cheaper VOC sensors that estimate CO2 levels, these use photoacoustic technology to measure the actual concentration of CO2 in the air.
The setup for the Raspberry Pi 5 (and older models) involves the I2C interface.
1. Hardware Connections (I2C)
The module communicates via I2C, which only requires four wires. Note that while these sensors can handle 5V power, the Raspberry Pi's logic pins are 3.3V. Ensure your module's I2C lines are compatible (most breakout boards from Adafruit/PiShop have 3.3V regulators/shifters built-in).
| Sensor Pin | Raspberry Pi Pin | Physical Pin # |
| VIN / VCC | 3.3V (or 5V if supported) | Pin 1 (3.3V) or Pin 2 (5V) |
| GND | Ground | Pin 6 |
| SCL | I2C Clock (GPIO 3) | Pin 5 |
| SDA | I2C Data (GPIO 2) | Pin 3 |
2. Enable I2C on the Raspberry Pi
Before you can read the data, you must enable the I2C port:
Run
sudo raspi-configin the terminal.Navigate to Interface Options > I2C.
Select Yes to enable it.
Reboot your Pi.
(Optional) Check if the sensor is detected by running
i2cdetect -y 1. The SCD4x should appear at address 0x62.
3. Install the Python Library
The easiest way to interact with the SCD4x in 2026 is via the Adafruit CircuitPython library, which is fully compatible with standard Raspberry Pi OS.
# It is recommended to use a virtual environment on the Pi 5mkdir co2_project && cd co2_projectpython3 -m venv .venvsource .venv/bin/activate# Install the librarypip3 install adafruit-circuitpython-scd4x
4. Python Example CodeThis script initializes the sensor and prints the CO2, Temperature, and Humidity readings every two seconds.
import timeimport boardimport adafruit_scd4x# Initialize I2C bus and sensori2c = board.I2C()scd4x = adafruit_scd4x.SCD4X(i2c)print("Serial number:", [hex(i) for i in scd4x.serial_number])# Start the sensor's internal measurement cyclescd4x.start_periodic_measurement()print("Waiting for first measurement (takes ~5 seconds)...")try: while True: if scd4x.data_ready: print(f"CO2: {scd4x.CO2} ppm") print(f"Temperature: {scd4x.temperature:.1f} °C") print(f"Humidity: {scd4x.relative_humidity:.1f} %") print("-" * 20) time.sleep(2)except KeyboardInterrupt: # Important: Stop measurements to save power/sensor life scd4x.stop_periodic_measurement() print("Measurements stopped.")
Key Differences for SCD41 UsersIf you specifically have the SCD41, you have a few extra features:
- Single Shot Mode: The SCD41 can take a single measurement and go back to sleep, which is better for battery-powered projects. The SCD40 must remain in "periodic" mode.
- Extended Range: The SCD41 reads up to 5,000 ppm (and even up to 40,000 ppm in "extended" mode), whereas the SCD40 is optimized for indoor air quality up to 2,000 ppm.
Pro Tips
If you are using this sensor for a commercial project in South Africa (like a school ventilation monitor), look into Automatic Self-Calibration (ASC). By default, these sensors calibrate themselves based on the lowest CO2 reading they see every week. If your room is never fully ventilated (never hits 400ppm), the sensor's readings will "drift." You can disable ASC in the code if you prefer to do a manual calibration outdoors.
- VCC is the positive power supply
- GND is the ground
- SCL is the I2C/SPI clock
- SDA is the I2C/SPI data
- SDO is the SPI data
- CS is the SPI slave enable.
What's in the box?
1 x BME680 sensor
1 x 6 pin header
Resources
Since you are likely using a Raspberry Pi 5, the process is now streamlined through virtual environments and the CircuitPython/Blinka library.
1. Hardware Connections (I2C)
The BME680 supports both I2C and SPI, but I2C is the simplest way to wire it.
| BME680 Pin | Raspberry Pi Pin | Physical Pin # |
| VIN / VCC | 3.3V Power | Pin 1 |
| GND | Ground | Pin 6 |
| SCL | I2C Clock (GPIO 3) | Pin 5 |
| SDA | I2C Data (GPIO 2) | Pin 3 |
Address Tip: By default, the I2C address is usually 0x77. If your module has an "SDO" pin and you connect it to Ground, the address changes to 0x76.
2. Enable I2C
Run
sudo raspi-config.Go to Interface Options > I2C and select Yes.
Reboot your Pi.
Verify the sensor is seen:
sudo i2cdetect -y 1. You should see77or76in the grid.
On Raspberry Pi OS (Bookworm and later), you must use a virtual environment.
mkdir bme_project && cd bme_project
python3 -m venv .venv
source .venv/bin/activate
# Install the Blinka compatibility layer and the BME680 library
pip3 install adafruit-blinka adafruit-circuitpython-bme680
This script will read all four sensors.
import time
import board
import adafruit_bme680
# Create sensor object using the default I2C bus
i2c = board.I2C()
bme680 = adafruit_bme680.Adafruit_BME680_I2C(i2c)
# Change this to match your local sea-level pressure (hPa) for accurate altitude
bme680.sea_level_pressure = 1013.25
print("BME680 Warming up (Gas sensor needs ~30 mins for total stability)...")
try:
while True:
print(f"\nTemperature: {bme680.temperature:.1f} °C")
print(f"Gas Resistance: {bme680.gas} ohms")
print(f"Humidity: {bme680.relative_humidity:.1f} %")
print(f"Pressure: {bme680.pressure:.2f} hPa")
print(f"Altitude: {bme680.altitude:.2f} meters")
time.sleep(2)
except KeyboardInterrupt:
print("\nProgram stopped.")
- The "Burn-In" Period: When you first receive the sensor, Bosch recommends running it for 48 hours continuously to stabilize the gas sensor. After that, run it for 30 minutes before trusting any "Gas Resistance" values for a specific session.
- Self-Heating: Because the BME680 has an internal heater for the gas sensor, the temperature reading can be 1.5°C to 3°C higher than the actual room temperature. In your code, you should subtract an offset (e.g.,
bme680.temperature - 2.5) to get an accurate reading. - Gas vs. CO2: Remember that the BME680 measures VOCs (Total Volatile Organic Compounds), not specific CO2. If you need a "True CO2" reading, you should pair this with the SCD40/41 we discussed earlier
1.3-inch 4-pin I2C OLED Display Module (SH1306, 128x64 Pixels)
The 1.3-inch OLED display is a high-contrast, compact screen ideal for adding user interfaces, data readouts, or graphical feedback to your microcontroller projects. Featuring the SH1306 driver, this module offers a resolution of 128x64 pixels and produces bright, crisp visuals with deep blacks, as each pixel is self-illuminating and requires no backlight.
This specific model comes pre-soldered, allowing for immediate integration into your projects without the need for manual header installation. Its I2C (IIC) interface ensures simple, space-saving communication, requiring only four pins to operate.
Key Features
- Display Quality: 128x64 high-resolution display with a wide viewing angle and high contrast ratio.
- Driver IC: Uses the reliable SH1306 controller, widely supported by popular libraries.
- Compact & Low Power: Small 1.3-inch form factor that consumes very little power, perfect for battery-operated devices.
- Simple Interface: Uses the I2C protocol, keeping your wiring clean with only four connections (VCC, GND, SCL, SDA).
- Pre-Soldered: Equipped with a pre-soldered header for immediate use on breadboards or custom PCBs.
- Versatile Compatibility: Compatible with Arduino, Raspberry Pi, ESP32, ESP8266, and other popular development boards.
Technical Specifications
| Parameter | Detail |
| Screen Size | 1.3 inches |
| Resolution | 128 x 64 pixels |
| Driver IC | SH1306 |
| Interface | I2C / IIC |
| Supply Voltage | 3.3V – 5V DC |
| Viewing Angle | > 160° |
| Display Color | Usually Blue or White (depending on model) |
Typical Applications
- Smart Wearables: Creating readable interfaces for custom fitness trackers or watches.
- Project Monitoring: Displaying real-time sensor data from temperature, pressure, or air quality sensors.
- Menu Systems: Building navigation menus for hand-held control devices.
- Portable Instruments: Compact, high-visibility readouts for custom testing equipment.
What's in the box?
1 x 1.3inch OLED display
Resources
Using the 1.3-inch SH1306 OLED with a Raspberry Pi is a great way to provide a visual interface for your projects. Since it uses the I2C interface, the wiring is simple and identical to the sensor module we discussed earlier.
Wiring Guide
Ensure your Raspberry Pi is powered off before making these connections.
| OLED Pin | Raspberry Pi Pin (GPIO) |
| VCC | 3.3V (Pin 1) |
| GND | GND (Pin 6 or 9) |
| SCL | SCL (Pin 5) |
| SDA | SDA (Pin 3) |
Step-by-Step Setup
1. Enable I2C:
- If you haven't already, run
sudo raspi-config. - Navigate to Interface Options > I2C and enable it.
- Reboot the Pi.
2. Verify Detection:
- Run
i2cdetect -y 1. - You should see a hex address appear in the grid (typically
0x3c). This confirms the Pi is communicating with the display.
3. Install Python Libraries:
- The Luma.OLED library is the industry standard for driving these displays on Raspberry Pi.
- Install the dependencies:
sudo apt-get install python3-pip python3-dev libfreetype6-dev libjpeg-dev build-essential- Install the library:
sudo pip3 install luma.oled
4. Running a Demo:
- Luma includes a set of examples. You can navigate to their GitHub repository or run a simple test script to verify your display.
Important Tips
- Driver Configuration: Many tutorials online default to
ssd1306. If your display shows distorted images or shifted columns, you are likely using the wrong driver. Always double-check that your code initializes the device as ansh1306. - Power: While most of these modules are 5V tolerant, it is safer to use 3.3V to match the logic levels of the Raspberry Pi's GPIO pins.
- Refresh Rate: If you are planning to show animations, keep in mind that I2C is slower than SPI. For standard text and simple graphics, I2C will be perfectly responsive.
Precision Growth: Corrosion-Resistant Capacitive Soil Moisture Sensor
Elevate your automated gardening or agricultural projects with our High-Durability Capacitive Soil Moisture Sensor. Unlike traditional resistive sensors that use exposed metal prongs prone to rapid oxidation, this module utilizes capacitive sensing technology to measure soil moisture levels without direct electrical contact with the soil.
Key Features
Corrosion-Resistant Design: Built with high-quality materials that prevent the electrodes from rusting or degrading over time, significantly extending the sensor's lifespan in damp environments.
Capacitive Sensing Technology: Measures changes in capacitance caused by the dielectric permittivity of the soil. This means no DC current flows through your soil, preventing electrolysis and nutrient depletion around the probe.
Onboard Voltage Regulator: Supports a wide operating voltage range (3.3V to 5.5V), making it directly compatible with Arduino, Raspberry Pi, ESP32, and STM32 platforms.
Analog Output: Provides a simple linear analog voltage output, allowing for easy calibration and integration into your existing codebases.
Technical Specifications
| Feature | Specification |
| Operating Voltage | 3.3V ~ 5.5V DC |
| Output Voltage | 0 ~ 3.0V DC |
| Interface | PH2.0-3P (Analog) |
| Dimensions | 98mm x 23mm |
| Technology | Capacitive (Non-resistive) |
Why Choose Capacitive over Resistive?
Most entry-level sensors work on resistance, essentially "sacrificing" the metal on the probe to get a reading. After a few weeks, those sensors often fail due to heavy oxidation.
The Capacitive Advantage: By acting as a capacitor, the probe is coated in a protective layer. It "feels" the moisture through the insulation, ensuring your automated irrigation system stays reliable for seasons, not just weeks.
Ideal Applications
Smart Agriculture: Large-scale crop monitoring where sensor longevity is critical.
Indoor Gardening: Automated watering systems for houseplants or "smart" terrariums.
Environmental Research: Long-term soil data logging in various climates.
DIY Robotics: Perfect for students and hobbyists building their first IoT garden.
Quick Connection Guide
VCC: Connect to 3.3V or 5V.
GND: Connect to System Ground.
AOUT: Connect to any Analog-to-Digital Converter (ADC) pin on your microcontroller.
What's in the box?
1 x Capacitive Soil Moisture Sensor Module
Resources
To use this capacitive soil moisture sensor with a Raspberry Pi Pico, you will need to utilize one of the Pico’s Analog-to-Digital Converter (ADC) pins. Since the Pico’s GPIO pins are digital-only by default, only specific pins (GP26, GP27, and GP28) can interpret the varying voltage signals from the sensor.
Wiring Connections
Connect the sensor to your Pico using the following pinout:
VCC (Sensor) to 3V3 (Pin 36) on the Pico.
GND (Sensor) to any GND pin (e.g., Pin 38) on the Pico.
AOUT (Sensor) to GP26 (Pin 31 / ADC0) on the Pico.
MicroPython Implementation
The Pico’s ADC converts the sensor's analog voltage (0V to 3.3V) into a digital value ranging from 0 to 65535. Because this is a capacitive sensor, the value will be higher when the soil is dry and lower when the soil is wet.
import machine
import utime
# Initialize ADC on Pin 26
soil_sensor = machine.ADC(26)
# Calibration values (To be adjusted based on your specific sensor)
# Dip the sensor in water to find 'wet' and leave in air to find 'dry'
DRY_VALUE = 45000
WET_VALUE = 18000
while True:
# Read raw analog value
raw_value = soil_sensor.read_u16()
# Convert raw value to percentage
# (High value = Dry, Low value = Wet)
moisture_percent = (DRY_VALUE - raw_value) * 100 / (DRY_VALUE - WET_VALUE)
# Constrain percentage between 0 and 100
moisture_percent = max(0, min(100, moisture_percent))
print(f"Raw Value: {raw_value} | Moisture: {moisture_percent:.1f}%")
utime.sleep(1)
Calibration Tips
Since every sensor and soil type varies slightly, you should perform a manual calibration for accuracy:
Dry Point: Hold the sensor in open air and record the
raw_value. UpdateDRY_VALUEin the code.Wet Point: Submerge the sensor in a glass of water up to the maximum immersion line (do not submerge the electronics at the top) and record the
raw_value. UpdateWET_VALUE.
Power Management
The sensor is rated for 3.3V to 5.5V. While the Pico’s 3.3V output is convenient and safe for the ADC pins, using the VBUS pin (5V) may provide a more stable signal if you are using long jumper wires, but you must ensure the sensor's output voltage does not exceed 3.3V to avoid damaging the Pico.
Are you planning to use this sensor for a simple automated watering system or a more complex data-logging project?
Proximity switch, also known as non-contact proximity switch, is the ideal electronic switch sensor. Used for detecting metal in proximity. It does not require any contact or pressure. It will accurately reflect the position of a moving mechanism. The proximity switch is easy to install, adjustable, and suitable for harsh environments.
Specifications
- Model : LJ12A3-4-Z/BY
- Operating Voltage : DC 6-36V
- Output Type : PNP
- Output Status : Normally Open
- Detection object : metal objects
- Detection distance : 4 mm
- Output Current : 300 mA
- Response Frequency : 0.5KH
- Working temperature : Temperature range -30 ° to 60 °
- Dimensions : 12 mm screw diameter
- Cable length : about 115 cm
- Material : Metal and plastic
What's in the box?
1 x LJ12A3-4-Z/BY PNP Sensor Detection Switch
Resources
Brown - Live
Blue - Ground
Black - Signal
This OLED goes out to all the fans who want more pixels in a smaller size! Normally our 128x64 OLEDs are the biggest ones we've stocked that can use I2C. This one is a whopping 128x128 pixels in crisp monochrome.
This display is a petite 1.12" diagonal, but very readable due to the high contrast of an OLED display. This display is made of 128x128 individual white OLED pixels, each one is turned on or off by the controller chip. Because the display makes its own light, no backlight is required. This reduces the power required to run the OLED and is why the display has such high contrast; we really like these miniature displays for their crispness!
The driver chip, SSD1107 can communicate in two ways: I2C or SPI. The OLED itself requires a 3.3V and 12V power supply and 3.3V logic levels for communication. We include a 3.3V regulator and 12V boost converter, and all pins are fully level shifted so you can use with 3V or 5V devices!
If you are using I2C, we've included SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don't even need to solder! Plug and play with any board that has a Qwiic or STEMMA QT connector for effortless prototyping and development. QT Cable is not included, but we have a variety in the shop.
This display, being 128x128 pixels, requires 128 * 128 = 2KB of SRAM just to buffer the display. So you can't use it with a small chip such as the Arduino UNO (ATmega328 or 32u4). Pick a microcontroller or microcomputer with 16KB+ RAM - a SAMD21, SAMD51, ESP, nRF52, Teensy, etc will do an excellent job. As long as you have I2C or SPI interface available, you're good to go - SPI will be much faster but I2C requires fewer pins.
We have both Arduino and CircuitPython support for this display chipset (SH1107).
Please note that OLED displays are made of hundreds of...OLEDs! That means each pixel is a little organic LED, and if it's kept on for over 1000 hours it'll start to dim. If you want to keep the display uniformly bright, please turn off the display (set the pixels off) when it isn't needed to keep them from dimming.
Revision History
- As of October 2023 – we've updated this PCB with Adafruit Pinguin to make a lovely and legible silkscreen - you may get the new PCB or the older version with vector fonts - both are identical other than the fancy silkscreen.
OLED Display Details:
- Diagonal Screen Size：1.12"
- Number of Pixels：128 × 128
- Color Depth：Monochrome (White)
- Module Construction：COG
- Active Area (mm)：20mm x 20mm
- Pixel Size (mm)：0.15 x 0.15 mm
- Duty：1/64
- Brightness ( cd/m2): 100 (Typ) @ 12V
- Display current draw is completely dependent on your usage: each OLED LED draws current when on so the more pixels you have lit, the more current is used. They tend to draw ~35mA or so in practice but for precise numbers you must measure the current in your usage circuit.
- Product Dimensions: 40.5mm x 30.5mm x 6.0mm
- Product Weight: 6.4g
What's in the box?
1 x Adafruit Monochrome 1.12" 128x128 OLED Graphic Display
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