If you would like to experiment with the parts brfore building a final project, using a breadboard is the way to go. This allows you to check the circuit out and think about using different components. If you want to try things out, you can start with the first circuit below:
- Pulse Sensor Amped
- Adafruit Pro Trinket or Arduino Uno, Genuino, or Adafruit Metro
- 5 volt power supply (cell phone charger or wall to 5 volt supply)
- One or more Adafruit NeoPixel products, shown is the 24 NeoPixel Ring
- Half Breadboard
- 2.1 mm power supply adapter
- Large Capacitor and 470 ohm resistor
Some people use a great number of NeoPixels in their projects. Each pixel draws current and the current needs can add up. The current can vary depending on the colors and brightness you choose. The values in the code set the red to about 25% brightness on red with no blue or green LED use so the current needed is much less than setting all colors to maximum brightness.
The use of a large capacitor and a data line resistor are recommended in the Adafruit NeoPixel Überguide which I recommend you read before designing with NeoPixels. As the design below uses 24 NeoPixels, I added the components knowing that other designs might use many more pixels. The 24 pixels with the code settings selected draws 80 milliamps max, not too bad. For a small project (less than 30 pixels), you may forego the extra parts.
The breadboard circuit shows an Arduino Uno (or Genuino or Adafruit Metro, they have the same features) as the microcontroller. The pulse sensor code will work with any of the five volt ATmega 328 based AVR processor board with an analog input and a digital output. If you plan to work on the wearable version on the next page, you may wish to use the Pro Trinket 5 volt - it works the same as the Uno but is much smaller.
Due to the pulsesensor.com code, use of other microcontrollers other than a ATmega 328 would need recoding to set a 2 microsecond timer needed by the sensor. Recoding would include the Teensy line, popular with LED project designers.
For breadboarding, select a wall supply with a steady 5 volts. For up to 30 or so NeoPixels, the Adafruit 5 Volt, 1 amp USB supply works well. For many more pixels, consider the Adafruit 5V 10A switching power supply. If you plan to go portable, the wearable version on the next page shows how to do that.