crwper

Member Since: July 11, 2008

Country: Canada

Profile

Role

Programmer

Organizations

Mustagh Resources Ltd.

Spoken Languages

English

Programming Languages

C/C++, Python, and to a lesser extent Lisp and Erlang

Universities

B.Sc. Physics and Pure Mathematics, University of Calgary

Interests

BASE jumping, skydiving, electronics

  • News - According to Pete - Spect… | about 11 months ago

    How about a simple strip of coloured LEDs arranged like a VU meter? Could be very useful for any wearable “meter”, since you ideally want the LEDs to have a fairly regular spacing–not easily achievable by sewing single LEDs in place.

  • Tutorial - The FCC and Open Source Hardware | about a year ago

    You don’t have to pay the entire cost of testing up front, so what you would usually do is to perform the tests you’re most likely to fail first. If you fail a test, you need only repeat the tests you’ve already done.

    You can also do “pre-compliance scans”–not as detailed as the full test, but they are cheaper and will give you an idea if something is going very wrong.

  • News - Aaron's High Altitude Bal… | about 2 years ago

    I got an estimate recently from one testing company for FCC/CE testing for an intentional transmitter. Just the Bluetooth part of things will run about $10-$13k. The non-transmitting stuff runs another $15k or so.

  • Product GPS-00465 | about 2 years ago

    Probably way too late for you, but I wanted to add that receivers based on the u-blox 6 chipset will definitely work up to 50 km altitude and 500 m/s speed (independent limits). Above 600 m/s, position will not be reported. Otherwise, there is no limit on altitude alone.

  • News - New Product Friday: Stick… | about 2 years ago

    I’ve noticed the same with my own designs based on the Venus. I really appreciated Venus' customer support, but I can’t say I ever had good results with their receiver. The old 10 Hz data looked interpolated. Compared to data from a u-blox receiver, the Venus showed almost a second of lag. It seems highly unlikely that they’ve managed 20 Hz of usable GPS data at this price.

  • Product TOL-10806 | about 3 years ago

    Another potential difference: Doing a bit more research, the ADS1102C seems to have 500 MSa/s single-channel sampling rate (the same as specified here) and 250 MSa/s double-channel rate. This could explain the discrepancy with the specs on the product page linked above, which seems to be for the ADS1102CML.

  • Product TOL-10806 | about 3 years ago

    I think I’ve found the difference… The scope pictured here seems to be an ATTEN ADS1102C:
    http://www.google.ca/search?tbm=isch&q=ads1102c
    Compare this with photos of the ADS1102CML:
    http://www.google.ca/search?tbm=isch&q=ads1102cml
    The 1102C, for example, seems to have a 5.7" display, whereas the 1102CML has a 7" display. The product page linked above shows data for the CML series, but there is no mention of the scope SparkFun is selling.

  • Product TOL-10806 | about 3 years ago

    The photos here look quite different from the 1062CML shown on the product page–in particular, the aspect ratio of the screen catches my eye. Do these units have a 7" display?

  • News - Fritzing! | about 3 years ago

    I recommend that you actually pay for it. Someone’s put a lot of work into that software, and it’s available for a fraction of the cost of a license of, e.g., Altium. I think it’s awesome that they provide a free version, but, as a software developer, let me assure you that free versions don’t pay the bills. What pays the bills are the folks who can make use of the full version–like yourself. Please don’t rip off a company that actively supports hobbyists.

  • Product COM-09312 | about 3 years ago

    To add to this suggestion… Rather than multiplying the output voltage, I’ve gotten better results feeding it into an op amp comparator, like this:
    http://en.wikipedia.org/wiki/Operational_amplifier_applications#Comparator
    V1 comes from the pulled-up Hall sensor output, and V2 comes from a voltage divider set to give 250 mV. The output will go to one rail or the other depending on the sensor’s output.
    This setup has a couple of advantages. First, it goes all the way to GND and VCC. Second, if you have more than one Hall sensor, it will require only one voltage divider (one op amp per input with the voltage divider’s output going to each one).

No public wish lists :(