Tangent Audio : CAVE Development Progress Log

Development Progress Log

Note: this list is terribly out of date and does not include any information about the MkII player development. Sorry!
April, 2001 - Presently working on MkII player design. It will feature USB, improved playback capabilities, smaller physical size, and much more!
March, 2001 - Designed and manufactured the color head unit PC board.
February-March 2001 - Schematic capture and PCB design for color head unit controller PCB.
December 2000-January 2001 - Took a break from Development.
November 15-30, 2000 - On vacation. Rented a car with a NeverLost GPS system. Took some pictures of the unit for mounting ideas, etc.
November 5, 2000 - Built an adapter socket to add 32KB of SRAM to the prototype head unit PCB.
November 4, 2000 - Re-connected the development system and brought the old firmware up-to-date with the color display drivers. Only infrared control is available at present (need to build the touch screen interface circuit).
September 25-November 3, 2000 - Took a break from development.
September 18-24, 2000 - Working on mechanical design for the player. Produced a rendering showing the drive being removed and another rendering with the drive installed.
September 16, 2000 - Mocked up touch screen keypad to verify size of on-screen keys. Seems to be reasonably sized to have a full QWERTY keyboard implemented on the touch screen. This will be used for searching for artists/albums/tracks.
September 10, 2000 - Successfully rewrote proportionally-spaced font rendering routines. Most of the elements are now in place to re-build the head unit with the color display for actual operation. Until now it has been used standalone to develop code for the display.
September 9, 2000 - Experimented with album cover thumbnail display. Results are very encouraging.
September 7, 2000 - Received the color displays for the head unit today. I connected one onto the prototype board I was using for the head unit (after removing the old monochrome display). With a little bit of code I was able to get some simple graphics to work. I then wrote a simple font rendering routine to display 6x8 fixed-width fonts with adjustable foreground and background colors. Once the simple font rendering routine worked, I moved on to graphics.
September 3, 2000 - Progress is good on the schematics for the first real board design. The intent is to produce five boards to test out the design and work out any remaining bugs. Once these five have been produced and debugged, additional boards may be made depending on the level of interest from friends. The first boards will support both the MAS3507D and the STA013 MP3 decoder ICs.
August 28, 2000 - Tested 60GB Maxtor disk with only half-success. Must investigate power supply issues. Constructed interface circuit for Sony RMX-4S wired "stick" remote controller. Connected to micro in head unit, wrote code. Controller is working as expected, returning unique codes for each stick position. Head unit can now be controlled from stick controller, an infrared remote, and the front-panel softkeys.
August 27, 2000 - Infrared remote control support added, working with existing head unit and software in a primitive fashion. Advanced features will come with protocol and code re-design. At this time only Sony remotes are supported.
August 26, 2000 - Demo Car with MkI player and MkI head unit demoed at Purgatory Chasm for the GweepNet community. Everyone who saw it enjoyed the demo and provided lots of encouragement.
August 25, 2000 - New power supply prototype with tighter parts placement solves some problems with the MkI player. PCB with ground plane on entire rear of board helps to keep noise down.
August 14, 2000 - Road testing player during commute to/from work. Dropout problems in playback. After much diagnosis and investigation it seems to relate to power supply noise on the 12V-12V DC-DC converter corrupting the data stream to the MP3 decoder.
August 22, 2000 - Ran CAVE off of two 6V 10Ah lead acid batteries for over an hour. Conservatively it should run for at least 6-8 hours on these batteries. MP3 boom box anyone?
August 21, 2000 - Implemented a prototype protocol for head unit to player communication. It's now possible to navigate the directory structure and play individual songs or playlists using the head unit.
August 14, 2000 - Removed command-line debug interface in favor of a VT100 single-key-driven interface. Much easier to use from the Pilot.
August 9, 2000 - Implemented C stdio library functions for fopen(), fclose(), fread() and fgets(). Wrote code to read and play Sonique playlists using these routines. This makes it easier to use the Pilot as an input device since it reduces the amount of interaction necessary.
August 8, 2000 - Many bug fixes to FAT32 code fixing issues with deleted files, returning to root directory, etc.
August 6, 2000 - First mobile test in the demo car using a Palm Pilot for control. Successfully played two songs on trip from home to a gas station and back. Command line interface is very cumbersome to use via the Pilot in the car.
August 5, 2000 - Automotive power supply connected to prototype and tested in the lab.
August 4, 2000 - Constructed first automotive power supply prototype.
August 2, 2000 - Power supply prototyping components ordered from Digikey.
July 31, 2000 - Samples of switcher IC finally received.
July 16, 2000 - Put MkI player into enclosure. The front of the unit has a removable 3.5" IDE drive bracket. The rear of the unit has power input, audio output, a connection to the head unit, and two fans. Also, the original CAVE web site went online.
June 30, 2000 - Ordered samples of switching power supply controller IC.
Late May/Early June - Took a break from development
May 13, 2000 - Wrote proportionally spaced font rendering routines for a nice 240x64 monochrome LCD. This will be similar to the display I end up using in the head unit.
May 2, 2000 - Sony "rotary commander" stick controller received and reverse engineered. Interface to the unit is not an intelligent protocol as had been expected, but rather a much simpler scheme.
May 1, 2000 - I2C communications from microprocessor to MP3 decoder chip and DAC working. FM tuner now connected through DAC's auxiliary inputs.
April 30, 2000 - Prototyped the FM tuner module using an evaluation board. The tuner receives many radio stations with no antenna or shielding. It receives many more with proper shielding and an antenna. In the future, an external tuner module may be offered for folks who have no existing radio in their car.
April 28, 2000 - Optimizations to the interface for the MP3 chipset allows for 320kbit audio playback from contiguous files on FAT32 disk.
April 26, 2000 - 128kbit audio working from IDE disk (FAT32, but playback not following FAT - assumed contiguous files)
April 25, 2000 - Constructed new IDE interface on a new evaluation board. Ported old code to new board.
April 18, 2000 - First sputtering bits of audio (Toad The Wet Sprocket's Amnesia encoded at 56kbit) from MIDIbrick/IDE kludge.
March 29, 2000 - Kludged an IDE disk onto the MIDIbrick development board. Able to read/write raw sectors.
August 1999 - Received eval board for Micronas MAS3507D & DAC3550A. Runs bit-banged from PC parallel port.