SparkFun will be closed Nov 26th and 27th for the Thanksgiving holiday. Orders placed after 2:00pm MT on the 25th will ship out Monday the 30th.

Member #344403

Member Since: August 9, 2012

Country: United States

  • I have read that current mirrors are commonly used in op-amp circuits, I’m a newbie, so I don’t know why. Can anyone explain this? Would such a design work for discrete linear amps?

  • What does it mean, in practice, that the PCduino supports Linux and Ubuntu? Does it require that you use a Linux flavor OS in the computer with which you program it? Do you need to know Linux features in order to program and use the board? Or is the embedded OS transparent?

  • So, I take it the mbed DIP is the development board? And you plug it into the application board (the other mbed product you sell) to get access to the peripherals on the latter?

  • Chip Quik sells a tin+bismuth paste with a very low m.p. See CN Lohr’s you tube vids about this. With this stuff, he solders his boards over a 250W halogen work lamp, or uses a hot-air gun.

  • It strikes me that this might make a decent display for a DIY oscilloscope. 400 pixels vertical is ample, compared with most low-cost ‘scopes on the market, which are 8-bit precise in voltage. With the extra ~140 pixels, you could have some extra headroom for dual-trace, perhaps. But I don’t know yet how this screen is refreshed, and how fast. Is the entire display refreshed at regular intervals? Or, alternatively, does every pixel remain lit until it is individually addressed and turned off, the opposite for turning on a pixel? Any thoughts?

  • What is up with Bildr? To register, they require a question answer that I’ll bet most people don’t know off the top of their heads. I looked it up in Wiki. When I returned to their registration site, I was told that I had attempted to register too many times and had to wait. I waited 15 mins, and they still won’t accept my registration. Not only that their is no “contact” service, so I can’t ask them for help. Apparently, they don’t want members. SO, will you please drop them and find some other place to put tutorials?

  • 30g is just 2g over an oz. Maybe someone got confused about the quantities.

  • I was trying to find the resolution (in bits) and speed of the Analog In ports. The manual’s discussion of resolution is awfully confusing in that it seems to contradict itself. It says the voltage between 0 and 3.3V is given in 255 steps, or 8-bit resolution. It then shows how to calculate voltage from the digital reading. When it does, it divides the reading by 1024, not 254 prior to multiplying by 3.3 V. This gives an answer in 10-bits, doesn’t it? Which is the right resolution, 8 or 10 bits? I couldn’t find the conversion rate anywhere. What is it, please?

  • Big plus - the wires are tinned, as shown in last photo. Protects from corrosion, tarnishing, and makes soldering a LOT easier than bare copper, esp. when it’s a bit old.

  • I think you can make a simpler TEC generator with wires of dissimilar metals - nichrome & copper for instance. Twist segments together at both ends and wire in series. One half of each pair is exposed to heat, the other to cool air. I haven’t done this, but practical generators for small heat generators like candles and oil lamps have been used to power small appliances. In the old Soviet days, I saw photos of folks (in Siberia, where the cold half was easy to find) gathered around oil/kerosene lamps that powered radios. Also, the Plutonium-powered electric sources in the Curiosity Mars lander run off the heat generated by simple radioactive decay.

No public wish lists :(