slow progression -- PAK - ook the modulator

The cheap microphone/demodulator I'm using was purchased from China for next to nothing and I got what I paid for. I can barely tell the difference between the signal in the background noise. You will see in the figures my signal-to-noise ratio is somewhere between three and four. This is with the low powered buzzer just inches from the microphone.

The cheap microphone will work for now, I bypassed the digital output from a comparator. Instead I am using the analog signal. yesterday's post was while I was still attempting to use the digital output.

Here are a couple references with the analog output from the microphone, in figure 1 I clapped three times, figure 2 there are several short pulses from a buzzer followed by a break ending with a long buzz, figure 3 I messed with the wiring a little bit and I think there may have been some improvement using the same procedure used in figure 2, however it may just be less noisy.

figure 1: clapping



figure 2: buzzer from 2 inches away


figure 3, rewired.

Before purchasing some transducers I want to get an idea of the noise environment I will be testing the system in. For now I will work with these cheap Chinese sensors to develop the software while I consider a more permanent transducer.