Timeline

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50 most recent timeline items

2015-07-21
22:54
[de135a2a11] Leaf: Get the manifest into the project. (user: rberteig, tags: better-CIC)
2015-07-17
18:00
[8a4059fa2f] Widen CICREG for safety with current bit depth computed at exactly 16 bits. Note that this reduced the per-interrupt time from 3.33 to 3.02 us in the fast case. (user: rberteig, tags: better-CIC)
17:34
[5a7ff9e994] Move definitions for the EEK pin and hobby servo pulse pin to slpear.h where they belong. Correct implementation of pdmspi_pulse() for 500 kHz MCLK. (user: rberteig, tags: better-CIC)
17:18
[fd7869b9f8] Improve documentation for clocking. (user: rberteig, tags: better-CIC)
2015-07-11
00:50
[66d81d770f] Checkpoint CIC filter configuration that provides PCM samples at about 7812.5 Hz with 16 bit precision from PDM clocked at 500 kHz. The reduction of the PDM clock brings it into one of the documented operational ranges for this microphone. The CIC filter still includes an 8 sample simple boxcar implemented by table lookup, but changes the second stage CIC filter to have one more integrator and a lower decimation factor. (user: rberteig, tags: better-CIC)
00:46
[30f8d97213] Adjust system clock up to max supported 30MHz from nominal 24MHz. Incidentally fix a bug that caused the actual clock to have been 12MHz not 24MHz. So this actually just a bit more than doubles the raw CPU performance available. (user: rberteig, tags: better-CIC)
2015-07-08
01:15
[be8cfef484] (untested) Work in progress on improving PDM to PCM conversion by re-arranging the CIC filter structure for better bit depth. (user: rberteig, tags: better-CIC)
2015-07-02
22:05
[5aebb7287d] Leaf: Added notes on FlashMagic configuration to the LPC project's documentation. (user: rberteig, tags: trunk)
2015-07-01
23:14
[957d720ccc] Merged packet recording and adjustable threshold features to trunk for today's blog post. (user: rberteig, tags: trunk)
21:06
[38353e8e2f] Leaf: Add the q command to set the EEK threshold used for e mode and GPIO13 pulsing. Clean up some leftover unused code from the packet mode development. (user: rberteig, tags: packets)
2015-06-30
23:54
[aa14127460] Introduce packetized recording mode, where the packet header includes the computed SPL to go along with the previous packet's audio samples. This involved some reworking of the data pump delivering samples to the UART in both pure recording and the new packet mode so that it was possible to start recording on a packet boundary. (user: rberteig, tags: packets)
01:07
[ce748fa947] Fixed a regression in the Lua CRC module, changed CRC polynomial to 0x12F which has better properties for short messages. (user: rberteig, tags: packets)
00:23
[eda3f16601] Continue fiddling with CRC8 implementation and demo, including a matcing Lua implementation and some test cases. (user: rberteig, tags: packets)
2015-06-25
23:35
[441d6bec5c] Introduce a CRC8 for use on both the Lua and firmware ends to validate the packet header. (user: rberteig, tags: packets)
21:36
[dd66d0e331] Change scared delta SPL threshold to 12dB from 6dB. (user: rberteig, tags: trunk)
2015-06-16
22:20 • Edit [8d8ccc7f52b757d1|8d8ccc7f52]: Add tag "blog-splear09". (user: rberteig)
22:18
[8d8ccc7f52] Merged to trunk for next blog post release. This has the nominally working email when startled script that can be configured to either email a plot of SPL or an MP3 of the room audio around the event. (user: rberteig, tags: blog-splear09, trunk)
22:15 • Edit [8b86ec7568155019|8b86ec7568]: Edit check-in comment. (user: rberteig)
22:11
[8b86ec7568] Leaf: Fixed double noise gate stages in the SoX filter pipeline, restored the companding stage that should have been after a single noise gate. Tweaked levels on the noise gate. Also merged the recorder into the main scared.lua script, so that it can send email when scared based on the GPIO pin signalling. The email has a noise gated companded and MP3 encoded copy of the audio from just before the trigger to some time after the trigger. MP3 is used because both Android and iPhone appear to be able to play it directly from an email attachment. (user: rberteig, tags: scared)
20:19
[202705fa2f] Demonstrate lanes by volleying a value among workers while watching the clock. (user: rberteig, tags: scared)
01:37
[9cfd1371f3] Cosmetic tweaks to clean up the interface to sysfsgpio.lua (user: rberteig, tags: scared)
01:36
[c9ee7aa3f9] Added new sysfsgpio module, and made lanes work for watching the GPIO pin separately from the recording. (user: rberteig, tags: scared)
2015-06-12
18:46
[bf4ef7c4ab] Tweaked output file name, fixed a typo in the record.lua demo. (user: rberteig, tags: scared)
2015-06-11
01:11
[0e2352e0f4] Make record use sox and lame in a pipeline to write MP3 format without saving any intermediate files. (user: rberteig, tags: scared)
2015-06-09
01:34
[54134cae6d] Name the file written with a time stamp, and also pass it through SoX to get an OGG/Vorbis file. (user: rberteig, tags: scared)
01:12
[1d21a5874d] Use Roberto's struct to build the AU file header, and include the (empty) optional comment string at its minimum length. (user: rberteig, tags: scared)
2015-06-06
01:03
[123e544590] Added demo scripts showing two ways to get at GPIO pins from Lua. (user: rberteig, tags: scared)
2015-05-24
06:48
[9f2b594b39] Very simple configuraton from scared.rc which must be a Lua chunk that returns a table containing configuration parameters. The only known parametner is address. (user: rberteig, tags: scared)
2015-05-23
00:53
[ff26d6954f] Create a simple recorder. (user: rberteig, tags: scared)
2015-05-22
23:23
[26b540b327] Merge in the scared.lua scripts for the latest blog post. (user: rberteig, tags: trunk)
22:25
[31ad4ca9c2] Fix published email address. (user: rberteig, tags: scared)
22:11
[782332c2d3] Improve documentation of the plotspl module. (user: rberteig, tags: scared)
18:49
[1a0f1273cd] Add graph of the event, covering about 20 seconds total, with the trigger at 33% of the way through. Changed to using mpack for mail delivery as it sends the simplest possible MIME container holding a PNG file. (user: rberteig, tags: scared)
2015-05-20
23:47
[b04cca0aaa] Snapshot noise monitor script with some tweaks since the blog post on 2015-05-08. (user: rberteig, tags: scared)
2015-04-17
22:06
[3b4f54236e] Caught a typo, and renamed readme.txt to readme.md in most folders. (user: rberteig, tags: trunk)
20:58
[907302d566] Merged current state of the SPLear firmware work in progress. Trunk now builds for LPCXpresso in the Debug configuration and for the SPLear in the Release configuration. Renamed the readme to Readme.md for better effect on Fossil, and updated the documentation to describe the build configurations and basic wiring for both boards. (user: rberteig, tags: trunk)
2015-04-16
23:13
[74d45231c9] Leaf: Implement servo output pulses as a side effect of SPI TXRDY interrupt counting. Command that from the main loop to get about a 40Hz servo pulse rate, scaled much like the LED so the servo moves boldly. Also implement the EEK! flag output on the unassigned GPIO P13 to match claims in the data sheet. Fix the SONAR configuration so that it is on by default when building for the LPCXpresso eval board, and off by default for the SPLear board. (user: rberteig, tags: SPLearProto)
18:21
[8f7df7dc69] Point blog link to the more specific category for posts about this project. (user: rberteig, tags: SPLearProto)
2015-04-04
01:48
[366a4fef56] Implemented a run-time selection of what prints on the UART based on received single characters. Included a help display and a way to dump the chip info in the menu as well. Added a print of every SPL computed in decimal for easy integration with systems that want a UART only connection. Includes various code cleanups and clearing of #if 0 blocks and such. (user: rberteig, tags: SPLearProto)
01:41
[3491d5277a] Clean up ifdefs around declarations of the clock config variables that are declared here with no board library in the build. (user: rberteig, tags: SPLearProto)
01:30
[9fa53ba49a] Pick PWM clipping bug fix from SPLear development. (user: rberteig, tags: trunk)
01:26
[3ad804ccc7] Add clipping to the PWM set functions. (user: rberteig, tags: SPLearProto)
2015-04-03
01:13
[e1d214cbeb] Snapshot of work in progress during bringup of the SPLear prototype boards. Branched to avoid immediate conflicts with ongoing blog posts based on the eval board. (user: rberteig, tags: SPLearProto)
2015-03-27
01:04
[1fe01e0ab5] Added second sonar driving the blue LED. The GRN sonar is active low during PCM sample processing. The BLU sonar is active low in the main loop. (user: rberteig, tags: trunk)
2015-03-17
00:48
[1d38441bbc] Added a mu-Law codec to the record over UART feature to provide for 14-bit effective dynamic range in the captured recordings, which matches the dynamic range actually produced by the PDM to PCM conversion as implemented. (user: rberteig, tags: trunk)
2015-03-10
22:54
[5218c33e38] Replaced subtracting average sample value with a simple single pole IIR high pass filter rolling off at 20Hz. Added mechanism for dumping scaled 8-bit PCM samples to the UART for analysis on the PC. Tested with recording of room audio. (user: rberteig, tags: trunk)
2015-03-06
00:24
[8de46c10f4] Merged latest demo board documentation improvements. (user: rberteig, tags: trunk)
00:22
[395121d803] Leaf: Added documentation on wiring the demo board for the SPL firmware demo. (user: rberteig, tags: LPC)
00:08
[cf49dbb08b] Clarify license terms for the repository as a whole and the PDMSPL firmware specifically. Also better document the process of getting started with the firmware in LPCXpresso. (user: rberteig, tags: LPC)
2015-03-05
23:27
[383d02d249] Rename workspace folder to fix typo. (user: rberteig, tags: LPC)