When it reads nothing
Most TK101 faults are one of a few, and the sketch's own output points at them: no LED is no power, a start-up message is the setup, a peak stuck at 0 is CLK or DATA, and small numbers are usually a microphone that works. Start from the symptom.
Symptom first
Three checks with no meter
| Check | Expect |
|---|---|
| The red LED | on whenever 3V3 is connected |
| The Serial Monitor at 115200 | no PDM did not start |
| The level sketch, clapping near the port | the peak jumps |
The first proves power, the second the pins and the mode, the third the microphone and both signal wires together.
Change one thing at a time
Go back to the level sketch from How loud is the room, the TK101 alone on GPIO 5 and 6, and get a peak that moves when you clap. Then add the TK103 and the live sketch. A fault that appears at one step belongs to that step.
Moving CLK and DATA to other pins is fine, as long as the sketch changes to match and the new pins are not strapping pins (0, 3, 45, 46), USB (19 and 20), or 35 to 37 on a board with octal PSRAM.
When it does not work
DATA may be floating: not connected, or on a different GPIO from the one the sketch names, so the ESP32-S3 counts noise. Check DATA reaches GPIO 6 and CLK reaches GPIO 5, and that the two share GND with the board.
Jumper wires on a breadboard lose contact easily, and CLK runs at about a megahertz. Push every wire home, keep them short, and check the red LED is still on.
It can be, by 5 V on 3V3 (over its 3.6 V maximum), by washing the board, or by compressed air or a vacuum at the port. If the wiring checks out, the LED is on, and a clap near the port still reads 0 after the offset is taken out, try the level sketch on a second board if you have one.
In the level sketch, a number that rises when you talk and jumps when you clap near the port. The size does not matter: speech at arm's length is only a few tens out of 32767.
The block's reference page: its pins, specifications and downloads.
TK101 PDM microphone →Edit this page — content/books/pdm-microphone/when-it-reads-nothing.mdx
Questions about this product
See what other owners have asked, and read their solutions.
PDM Microphone
Loading discussions…
Discuss this article
Ask about this page. The answer stays here, on the page it belongs to, for whoever hits the same wall next.