{"id":20113801,"url":"https://github.com/mkj/pru-mic","last_synced_at":"2025-06-12T00:33:39.706Z","repository":{"id":53678959,"uuid":"93171137","full_name":"mkj/pru-mic","owner":"mkj","description":"8 fast digital MEMS microphones input to a Beaglebone","archived":false,"fork":false,"pushed_at":"2021-10-12T03:15:07.000Z","size":814,"stargazers_count":13,"open_issues_count":0,"forks_count":1,"subscribers_count":3,"default_branch":"master","last_synced_at":"2025-05-06T12:38:07.881Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"C","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/mkj.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2017-06-02T14:02:14.000Z","updated_at":"2025-01-02T06:33:36.000Z","dependencies_parsed_at":"2022-08-27T23:11:50.019Z","dependency_job_id":null,"html_url":"https://github.com/mkj/pru-mic","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/mkj/pru-mic","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mkj%2Fpru-mic","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mkj%2Fpru-mic/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mkj%2Fpru-mic/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mkj%2Fpru-mic/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/mkj","download_url":"https://codeload.github.com/mkj/pru-mic/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mkj%2Fpru-mic/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":259370703,"owners_count":22847392,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-11-13T18:26:01.195Z","updated_at":"2025-06-12T00:33:39.680Z","avatar_url":"https://github.com/mkj.png","language":"C","funding_links":[],"categories":[],"sub_categories":[],"readme":"This project is 8 MEMS microphones input directly to a Beaglebone Black.\n\nThey each provide a 4mhz 1-bit PDM input stream, across 4 wires multiplexed on rising/falling clock signal. \nThe PDM microphone is a Knowles SPH0641LU4H\n\nThe project consists of \n\n- pru/ - the bit-banging GPIO driver for the PDM input, which runs on the realtime PRU units of the beaglebone. pru/bulksamp4.dtsi has instructions for the devicetree.\n- driver/ - a Linux kernel driver which presents /dev/bulksamp. Inputs are multiplexed bitwise, the 8 microphones each contribute a bit to a byte of input. I've tested on Debian 8.5 with 4.1.15-ti-rt-r43, the driver may require the [TI Processor SDK](http://www.ti.com/tool/PROCESSOR-SDK-AM335X) kernel rather than latest Debian.\n- pdm/ - a Python program to decode PDM bitstreams to audio data. This uses Numba to perform fast PDM decoding with a Cascaded integrator–comb (CIC) filter. It also has some waveform plotting code. Tested with Python 3.5.\n- bitex/ - a program to extract a single bitstream from /dev/bulksamp. This can be used to pipe a single microphone into the pdm program.\n- circuit/ - basic pinout\n\nThe code works as a prototype, though there are likely some specifics of my personal setup that I've neglected to mention.\n\nThe pdm/ kernel driver is GPL licensed, the rest is MIT. See LICENSE.\n\nMatt Johnston 2017 matt@ucc.asn.au\n\nThere are a few similar looking projects I've come across:\n\n- http://bela.io/\n- https://github.com/LCAV/CompactSix\n- https://www.seeedstudio.com/ReSpeaker-Mic-Array-Far-field-w%2F-7-PDM-Microphones-p-2719.html\n\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmkj%2Fpru-mic","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fmkj%2Fpru-mic","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmkj%2Fpru-mic/lists"}