Member Since: February 26, 2013

Country: United States

  • It’s measurements tend not to be accurate when it’s being vibrated (that’s what the “NS”, or noise pin is for, though it does not appear to pick up all vibrations that affect the sensor). I’ve had one on a handheld device for 2 years and it’s still working well (though it isn’t in environmentally challenging applications like weather balloons that probably require it to be in a complete sealed enclosure)

  • This is one of my favorite sensors.

    Here’s an open driver:

    The Arducorder mini, a handheld multisensor device, that includes a backpack board to make the Radiation Watch Type 5 more sensitive. Some of the posts also show histograms of pulse widths from this sensor, that appear to contain some energy-level information:

    OpenCT, an extremely low resolution scanner using this sensor and a radioisotope source:

  • That’s very interesting. I had wondered, given AMS’s extensive optical offerings, if the CCS811 was using a tiny NDIR. Would you happen to know of anyone who does make a tiny NDIR sensor? The TGS4161 seems to be using a metal oxide for CO2 sensing (RuO2), but I’m not super knowledgeable about gas sensing – is this just for the heater, and the sensitive element is something else?

    The CCS811 is very exciting given that it’s a tiny, low-power, entirely digital (I2C) indoor air quality sensor. Other inexpensive gas sensors have historically been comparatively huge, and a little wonky to deal with with those purely analog interfaces, and (if I remember correctly) have a lot of inter-part variance, making accuracy more challenging. The CCS811 excites me because it reminds me of the MLX90601 – the first (that I’m aware of) non-contact temperature sensor with a digital interface that included all the analog hardware in the tiny can. Sure, there were lots of thermopile sensors before it, but it’s the one that finally made it easy, and that you didn’t have to be a skilled analog engineer to have some confidence in the accuracy of your temperature readings – probably why they still produce them today, a decade later. The CCS811 (or something similar) I imagine will have a similar impact on the air quality sensing domain shortly.

  • If you don’t believe me, look it up! It currently costs between $0.01 and $0.20 per GB of high-speed bandwidth, depending on who you listen to, and what costs are rolled in (including the infrastructure). It’s even worse when you start talking about wireless internet or communications. For example, the cost of bandwidth in text messages is 4x the cost of bringing down data from the Hubble telescope. Sure, it costs money to build towers and stick up the infrastructure, but when you have 100,000 people in that area each paying you $100 a month, $1M per tower factors out to almost zero cost. Again, if you don’t believe me, look it up!

  • This is a classic straw-man argument for the cable companies. Bandwidth costs near zero, and metering it creates a false shortage entirely for the purposes of making more money. Folks in the US pay often more than double for high speed internet, which is in many cases half as slow!

  • When he sweeps the other orders off the desk, it made me laugh out loud.

  • It’s really timely that you’re discussing this, for the next iteration of the Open Source Science Tricorder project I’ve actually drafted a CC-BY-SA derived license that’s been modified both with much of the same IP language found in TAPR/CERN, and with the requirement that for for-profit use, 10% of the profits must be donated to a basic literacy or science education charity (though I think in the final version this will also allow a split between science/literacy charities and the EFF and/or OSHWA). Since a lot of folks are already using CC-BY-SA for open hardware, my hope is that this could be a drop-in replacement. I sent the draft to Alicia earlier this week to get OSHWA’s comments – I can send a copy your way if you’d like? I’m particularly interested in the charitable contribution percentage (10% net), and whether that’s a realistic number given typical margins. In the end the benefit in the form of charitable contributions are only as useful as the adoption rate of the license.

No public wish lists :(