Archive for August, 2009
The demoparty MAIN#4 will take place from October 2 to 4 in Arles (France) with a lot of famous teams from the demoscene. The theme of this demoparty is the lightness of code.
The idea here is to present a compo based on the Milkymist hardware platform within a month. It may be a 2D/3D compo (or 2D only) and must be less than 10min long.
If you have ideas and/or want to be part of this, there is a small wiki page at http://www.tmplab.org/wiki/index.php/DemoParty_Compo_with_MilkyMist. Feel free to subscribe and edit this page (or the discussion tab).
ML401 FPGA boards (on which Milkymist can run) or similar boards are wanted. Required feature set is:
- Virtex-4 FPGA (XC4VLX25 or better)
- 32-bit DDR SDRAM or 64-bit SDR SDRAM (no DDR2/DDR3), 32MB at least
- NOR flash, 1MB at least
- 24bpp VGA DAC
- AC’97 sound
- Optional but nice to have: CompactFlash card reader, with SystemACE controller chip
If you have a suitable board and would like to lend it to the demoparty project, thank you very much. Contact kiniou at gmail or sebastien dot bourdeauducq at lekernel.net.
Many people are asking me what gases are detected by the sensors. All I can do is quote the Figaro Sensors documentations:
“The TGS 2602 has high sensitivity to low concentrations of odorous gases such as ammonia and H2S generated from waste materials in ofﬁce and home environments. The sensor also has high sensitivity to low concentrations of VOCs such as toluene emitted from wood ﬁnishing and construction products.”
“The TGS 2600 has high sensitivity to low concentrations of gaseous air contaminants such as hydrogen and carbon monoxide which exist in cigarette smoke. The sensor can detect hydrogen at a level of several ppm.”
The data sheets do not say much more. In particular, I do not know if the sensors are sensitive to other types of gases, what the exact list is, and how they react to a mixture of gases.
Levels are read straight from the LTC2496 ADC, with 65536 being the maximum level, corresponding to a voltage of 1.65V at the output of the sensor. The sensors (TGS2600 and TGS2602 from Figaro) are powered at 3.3V through a 1k resistor. The sensor heaters are also (under-)powered at 3.3V, this seems to work even though it is out of the specs.
A new Twitter post is made every time a value varies by more by 30%, compared to the last posted value.
The port is mostly an evaluation, learning and experimentation tool. It will be used at the upcoming /tmp/lab FPGA workshop on August 29th (it’s still time to register!).
What is currently missing is support for input devices (a PS/2 core is missing). Also, this port crashes when the CPU data cache is enabled, which suggests a hardware problem as people working on the ucLinux port experience a similar issue.
Roughly two years after the very beginning of the project, the first “pre-alpha” release is now available.
Everything is still not finished – work must be done on the GUI, the interfaces, the MilkDrop features and the rendering quality. See the project roadmap for more information.
The source code of Milkymist is now available at http://github.com/lekernel/milkymist/tree/master.
It contains the full code that was previously hosted on a Subversion repository at milkymist.org. Now you can easily download complete snapshots of the latest source, and it’s easier to have many collaborators. From now on, I will use this as the official repository.
The uClinux port (currently in development) now also has its repository at http://github.com/lekernel/milkymist-linux/tree/master.
Some resources for using GitHub: