555 LED Flasher
Build an adjustable blinking LED with a classic NE555 timer; learn the timing-capacitor and resistor relationship.
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Build an adjustable blinking LED with a classic NE555 timer; learn the timing-capacitor and resistor relationship.
Make a small mono speaker amplifier and learn input coupling, gain, decoupling, and speaker polarity.
Use an LM358 as a light-level comparator so an LED turns on when the room gets dim.
Read a DHT22 and print temperature and humidity to the Arduino serial monitor.
Measure nearby objects with an HC-SR04 and make a buzzer beep faster as an object gets closer.
A light turns on after a random pause; press a button quickly and see your reaction time in milliseconds.
Use a PIR module and microcontroller to sound a small buzzer when motion is detected.
Read a digital one-wire temperature sensor and print the result to the serial monitor.
Turn the NE555 into an adjustable square-wave tone source for a piezo element; explore frequency by ear.
Connect an OPT3001 light sensor to a microcontroller and learn how lux changes with distance and angle.
Press a button to start one adjustable LED pulse, then estimate its duration from the timing resistor and capacitor.
Pair a 555 clock with the CD4017 counter to move one lit LED through ten outputs.
Make a slow RC oscillator with one SN74HC14 gate and use its logic output to blink an LED.
Build one bit of memory from two cross-coupled NAND gates with separate set and reset buttons.
Build a discrete astable multivibrator that alternates two LEDs without a timer IC.
Use an NPN transistor to switch a low-voltage relay coil and clamp its turn-off voltage with a diode.
Regulate a suitable low-voltage DC input to 5 V with an LM7805, then measure its load and heat limits.
Build a small adjustable regulator and use the LM317 reference equation to predict and measure output voltage.
Build a four-switch trainer that lights when an odd number of inputs are high, demonstrating XOR parity.
Load a pattern one bit at a time into an SN74HC595 and display its eight stored bits with LEDs.
Read temperature, humidity, and pressure with a BME280, then serve a small live dashboard from the ESP32.
Combine a DS3231 clock module and OLED to display the time while learning I²C and timekeeping backup.
Measure bus voltage and current for a small low-voltage USB load and calculate power in watts.
Build a small two-wheel robot that drives forward and backs up/turns when its ultrasonic sensor sees an obstacle.
Measure tilt from accelerometer axes and show an approximate angle on a small OLED.
Send a small sensor reading between two microcontroller boards over a low-cost 2.4 GHz radio link.
Drive a small unipolar stepper through a ULN2003 driver and move it with two direction buttons.
Display a changing score or countdown on an 8×8 LED matrix module using SPI-like serial control.
Read a load cell with the HX711, tare the platform, and calibrate against a known mass.
Log BME280 readings with timestamps to a microSD card for later graphing.
Use a 5 V SN74HCT125 to turn 3.3 V logic-high signals into 5 V logic outputs in one direction.
Decode a three-bit switch setting into one of eight active-low outputs and visualize the selected channel.
Build a one-bit full adder from XOR, AND, and OR gates, then check sum and carry for all input combinations.
Set a light threshold with a potentiometer and use an LM393 comparator to light an LED when a photoresistor sees darkness.
Compare an NTC divider with an adjustable reference and light an indicator when temperature crosses the chosen threshold.
Build a low-voltage non-inverting preamp for a small line-level signal. It boosts voltage, not speaker power.
Filter high-frequency noise with a one-pole RC network and buffer the result so a following stage does not load it.
Read the MCP9700A with the Pico ADC and convert its 500 mV offset and 10 mV/°C slope into Celsius.
Read the TMP117 signed temperature register over I²C and print Celsius values to the USB serial console.
Capture eight switch states in parallel with an SN74HC165, then shift them to the Pico over three GPIO wires.
Control several hobby servos from a PCA9685 PWM driver without using one MCU pin per servo.
Build two standalone CAN nodes and exchange short messages over a correctly terminated bench bus.
Assemble and characterize a stereo class-D amplifier using a properly laid-out TPA3116D2 module and a suitable DC supply.
Display temperature, humidity, pressure, and Bosch-algorithm air-quality estimates without mislabeling raw gas resistance as CO₂.
Read two Type-K thermocouples using two MAX6675 converter breakouts and compare temperatures on a display or serial console.
Generate four adjustable low-voltage analog outputs and learn DAC resolution, reference voltage, and output buffering.
Build an I²S-to-analog-to-speaker signal chain with a PCM5102A DAC and a separate TPA3116D2 amplifier module.
Use a temperature sensor, MOSFET, and PWM control to vary a small 12 V fan's speed as temperature rises.
Build a two-motor robot that follows a dark tape line using reflectance sensors and proportional steering.
Compare two light sensors and move a small panel mount toward the brighter side; use it as a low-voltage demonstrator.
Cascade two SN74HC595s to expand three Pico output wires into a 16-LED pattern panel.
Use two SN74HC74s as toggle flip-flops to count 555 clock edges in binary and inspect ripple timing.
Write a short byte string to an AT24C256C EEPROM, wait for its internal write cycle, and read it back over I²C.
Select one of eight low-voltage analog inputs with an SN74HC4051 and read it using the Pico ADC.
Build a bidirectional open-drain translator for SDA and SCL between 3.3 V and 5 V I²C buses using two BSS138 MOSFETs.
Configure the LM317 as a simple current source and calculate LED current from the resistor between OUT and ADJ.
Make a hobby voltmeter for 0–3.3 V signals with an ADS1115 breakout, then compare it with a multimeter.
Scale the full-adder design to four bits and watch each carry propagate to the next stage.
Clock the CD4060 from a 555 oscillator and compare the progressively slower binary-divided outputs.
Combine serial input and output registers into a compact control panel: eight buttons in, eight LEDs out, using six Pico signals.
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