Timeline

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50 most recent check-ins

2015-07-21
22:54
Get the manifest into the project. Leaf check-in: de135a2a11 user: rberteig tags: better-CIC
2015-07-17
18:00
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. check-in: 8a4059fa2f user: rberteig tags: better-CIC
17:34
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. check-in: 5a7ff9e994 user: rberteig tags: better-CIC
17:18
Improve documentation for clocking. check-in: fd7869b9f8 user: rberteig tags: better-CIC
2015-07-11
00:50
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. check-in: 66d81d770f user: rberteig tags: better-CIC
00:46
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. check-in: 30f8d97213 user: rberteig tags: better-CIC
2015-07-08
01:15
(untested) Work in progress on improving PDM to PCM conversion by re-arranging the CIC filter structure for better bit depth. check-in: be8cfef484 user: rberteig tags: better-CIC
2015-07-02
22:05
Added notes on FlashMagic configuration to the LPC project's documentation. Leaf check-in: 5aebb7287d user: rberteig tags: trunk
2015-07-01
23:14
Merged packet recording and adjustable threshold features to trunk for today's blog post. check-in: 957d720ccc user: rberteig tags: trunk
21:06
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. Leaf check-in: 38353e8e2f user: rberteig tags: packets
2015-06-30
23:54
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. check-in: aa14127460 user: rberteig tags: packets
01:07
Fixed a regression in the Lua CRC module, changed CRC polynomial to 0x12F which has better properties for short messages. check-in: ce748fa947 user: rberteig tags: packets
00:23
Continue fiddling with CRC8 implementation and demo, including a matcing Lua implementation and some test cases. check-in: eda3f16601 user: rberteig tags: packets
2015-06-25
23:35
Introduce a CRC8 for use on both the Lua and firmware ends to validate the packet header. check-in: 441d6bec5c user: rberteig tags: packets
21:36
Change scared delta SPL threshold to 12dB from 6dB. check-in: dd66d0e331 user: rberteig tags: trunk
2015-06-16
22:18
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. check-in: 8d8ccc7f52 user: rberteig tags: blog-splear09, trunk
22:11
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. Leaf check-in: 8b86ec7568 user: rberteig tags: scared
20:19
Demonstrate lanes by volleying a value among workers while watching the clock. check-in: 202705fa2f user: rberteig tags: scared
01:37
Cosmetic tweaks to clean up the interface to sysfsgpio.lua check-in: 9cfd1371f3 user: rberteig tags: scared
01:36
Added new sysfsgpio module, and made lanes work for watching the GPIO pin separately from the recording. check-in: c9ee7aa3f9 user: rberteig tags: scared
2015-06-12
18:46
Tweaked output file name, fixed a typo in the record.lua demo. check-in: bf4ef7c4ab user: rberteig tags: scared
2015-06-11
01:11
Make record use sox and lame in a pipeline to write MP3 format without saving any intermediate files. check-in: 0e2352e0f4 user: rberteig tags: scared
2015-06-09
01:34
Name the file written with a time stamp, and also pass it through SoX to get an OGG/Vorbis file. check-in: 54134cae6d user: rberteig tags: scared
01:12
Use Roberto's struct to build the AU file header, and include the (empty) optional comment string at its minimum length. check-in: 1d21a5874d user: rberteig tags: scared
2015-06-06
01:03
Added demo scripts showing two ways to get at GPIO pins from Lua. check-in: 123e544590 user: rberteig tags: scared
2015-05-24
06:48
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. check-in: 9f2b594b39 user: rberteig tags: scared
2015-05-23
00:53
Create a simple recorder. check-in: ff26d6954f user: rberteig tags: scared
2015-05-22
23:23
Merge in the scared.lua scripts for the latest blog post. check-in: 26b540b327 user: rberteig tags: trunk
22:25
Fix published email address. check-in: 31ad4ca9c2 user: rberteig tags: scared
22:11
Improve documentation of the plotspl module. check-in: 782332c2d3 user: rberteig tags: scared
18:49
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. check-in: 1a0f1273cd user: rberteig tags: scared
2015-05-20
23:47
Snapshot noise monitor script with some tweaks since the blog post on 2015-05-08. check-in: b04cca0aaa user: rberteig tags: scared
2015-04-17
22:06
Caught a typo, and renamed readme.txt to readme.md in most folders. check-in: 3b4f54236e user: rberteig tags: trunk
20:58
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. check-in: 907302d566 user: rberteig tags: trunk
2015-04-16
23:13
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. Leaf check-in: 74d45231c9 user: rberteig tags: SPLearProto
18:21
Point blog link to the more specific category for posts about this project. check-in: 8f7df7dc69 user: rberteig tags: SPLearProto
2015-04-04
01:48
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. check-in: 366a4fef56 user: rberteig tags: SPLearProto
01:41
Clean up ifdefs around declarations of the clock config variables that are declared here with no board library in the build. check-in: 3491d5277a user: rberteig tags: SPLearProto
01:30
Pick PWM clipping bug fix from SPLear development. check-in: 9fa53ba49a user: rberteig tags: trunk
01:26
Add clipping to the PWM set functions. check-in: 3ad804ccc7 user: rberteig tags: SPLearProto
2015-04-03
01:13
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. check-in: e1d214cbeb user: rberteig tags: SPLearProto
2015-03-27
01:04
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. check-in: 1fe01e0ab5 user: rberteig tags: trunk
2015-03-17
00:48
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. check-in: 1d38441bbc user: rberteig tags: trunk
2015-03-10
22:54
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. check-in: 5218c33e38 user: rberteig tags: trunk
2015-03-06
00:24
Merged latest demo board documentation improvements. check-in: 8de46c10f4 user: rberteig tags: trunk
00:22
Added documentation on wiring the demo board for the SPL firmware demo. Leaf check-in: 395121d803 user: rberteig tags: LPC
00:08
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. check-in: cf49dbb08b user: rberteig tags: LPC
2015-03-05
23:27
Rename workspace folder to fix typo. check-in: 383d02d249 user: rberteig tags: LPC
02:49
Source code for the SPL meter using a PDM microphone running on an NXP LPC812 CPU. This is a snapshot of the build environment, and testing here has concentrated on whether it builds for me in LPCXpresso running on Windows 7 Pro. check-in: 2dd7a655f3 user: rberteig tags: trunk
2015-03-04
22:22
Fixed project configuration issue in the board and chip sub-projects that caused the IDE to use the wrong runtime library and fail to locate printf(). The IDE can now build both release and debug configurations. Closed-Leaf check-in: 0873085600 user: rberteig tags: LPC