Using the SPLear with the Raspberry Pi
Recently we announced the SPLear™, a module that integrates a PDM microphone along with a small ARM CPU to act …
Category Archives: Technologies
SPLear Hobby Servo Drive
Last week we announced the SPLear™, a module that integrates a PDM microphone along with a small ARM CPU to …
Announcing the SPLear Board
Our series of posts about interpreting PDM audio with small microprocessors has been leading up to this point. We have …
SPL Measurement Experiments
This article will describe some experiments with measuring SPL from test signals played into our microphone through a headphone. This …
Performance of our PDM to PCM process in the LPC812
This article will discuss instrumenting the PDM to PCM conversion running in the LPC812, and report on the performance achieved. …
Diversion: What is Sound Anyway?
This post is discusses some interesting properties of sound itself, not all of which can be easily measured. This is …
Improved audio recording from the PDM microphone connected to an LPC812
This post continues experimenting with recording audio converted from PDM to PCM in an LPC812 CPU. The last installment passed …
Recording PCM audio from the PDM microphone connected to an LPC812
This post continues experimenting with the PDM conversion to PCM samples in an LPC812 CPU. From the earlier tests we …
Source Code for the LPC812 PDM SPL is online
I updated the fossil PDMStunts repository to include source code for computing SPL from PDM microphone data as described in …
Testing the PDM to SPL arithmetic
Since porting the PDM microphone SPL measurement code base from the ATTiny85 to the ARM based LPC8xx family, it would …
Words from Cheshire Engineering Corp. 