Electret Mic Sparkfun BOB-12758

The Electret Mic Sparkfun BOB-12758 is a small breakout board that pairs an electret microphone with an OPA344 op-amp preamplifier. It picks up voices, claps and knocks and amplifies them to a level that the analog input of an Arduino, ESP32 or other microcontroller can read directly, with no external audio codec needed.

Electret Mic Sparkfun BOB-12758 Specifications

• Microphone: omnidirectional electret capsule
• Preamplifier: Texas Instruments OPA344 op-amp, gain of about 60×
• Supply voltage: 2.7 V to 5.5 V, works with 3.3 V and 5 V boards
• Frequency range: 100 Hz to 10 kHz
• Output: analog audio on the AUD pin, centred at half the supply voltage
• Pins: VCC, GND and AUD

Electret Mic Sparkfun BOB-12758 Applications

• Clap switches and sound-activated lights
• Measuring noise levels in a room or workshop
• Sound detection projects with Arduino or ESP32
• Audio-reactive LED effects and simple audio sampling

What's in the Box

• 1 × electret microphone breakout board (BOB-12758)

Tip: With no sound, the AUD output sits at about half the supply, so a 10-bit Arduino ADC reads around 512. To get a sound level, sample the pin for a short window and use the difference between the highest and lowest readings.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.