SparkFun will be closed Monday 7/4 for the holiday. All orders placed after 2pm MT on Friday 7/1 will be shipped out next week.


Member Since: February 5, 2013

Country: United States

  • From this and your other reply, it would appear that you think the sensor is mounted in/on the bag itself. From the comments at the beginning of the code, this does not appear to be the case: the sensor is apparently mounted on the platform itself, not on the bag. The sensor is measuring the accelerations (movement or vibrations) that are imparted to the bag platform by the movement of the bag. Keep in mind that this is a 4G sensor: if the sensor were in the bag, you would need a sensor that could handle a much higher acceleration. Same thing for a gyro, it would have to support a very high angular rotation change rate. I agree that a 6-DOF in the bag could be a way to go, but it is at odds with Nate’s “no-modification” goal (he states he wants something that can easily be screwed to the platform) and it would need a very robust sensor.

    Because of the limitation of not mounting the sensor to the bag, you cannot measure the position of the bag or the accelerations that it experiences. You can only infer its movement based on its impacts with the platform and the resulting platform accelerations.

  • But the full ASCII character set is already only 7 bits?

  • Now there are some memories… although I guess yours are a bit older - the ASR-33’s were still around, but hardly used anymore - but I thought they were so amazing to watch: get up close and look at the mechanism and it looks like it as working like mad; but stand back and watch it and it’s tapping out characters excruciatingly slowly. Still, using key punches and waiting for printouts was the norm, and I remember thinking it was SO high tech when I could take a break from the keypunch and batch jobs, and use one of the new green-screen video terminals and a 300 baud acoustic coupler to dial into an interactive session. Talk about a rich user interface experience! I also remember when they installed two 14 inch diameter hard disk drives on my system a few years later - a total of 10 MB of storage! I thought I’d never be able to fill that up…

    Man, the the things I could’ve done if they had all of this stuff when I was a kid…

  • I like how the conductor is using a screwdriver as a baton - I assume that’s the technology class teacher?

  • You could split the hot and neutral wires (not ground!) and it will work. But working is not the same thing as being safe. There are a couple ways it can be done safely, and many ways that are not safe, all of which still “work.” The safest way may be to split the hot line power before the relay: one branch goes to the relay and the switched outlet, the other goes to an unswitched outlet where you plug in your power supply. But see Member #415973’s comment above about the dangers of having high voltage splices and low voltage wires in the same box.

    Iif you have to ask that question on a forum like this, I would guess you don’t have much experience with working on line voltage AC power, and I would recommend that you not try it.

  • Actually, if we are trying to be correct, a GFCI can help prevent you from getting a shock, that’s one of its major purposes. If you touch the hot wire, current will tend to flow through you to ground if possible: this current is a ground fault, and that current will cause an imbalance between the hot and neutral wires that are being monitored by the GFCI, and the current will be interrupted. This is the most common electrocution mechanism that may happen when you grab a hair dryer with wet hands, stick a knife or fork into a toaster to free jammed bread, etc.

    But it won’t protect you from a shock in the less common situation where you are completely isolated from ground, and you touch both the hot and neutral wires - in that case the current flowing through you is going back through the neutral line, so there is no imbalance. The rest of what you say is correct: the GFCI does not protect against overcurrent situations.

  • Not only is there a delay from when you press the key to when the pipe starts sounding, but that delay is different depending on the note - high notes with small pipes react faster than low notes with large pipes. So that delay is constantly varying as the organist goes up and down the scales. A big pipe organ looks like a complicated instrument at first glance, but it gets much more complicated when start looking at the details. Mastering a large pipe organ is truly an accomplishment!

  • You’ve probably figured it out by now, but just in case, try this:

    value = scale.getGram();
    Serial.println(value, 1);

    The “, 1” part is an extra parameter for the Serial.println() function call, which tells it how many decimal places to print when printing floating point numbers. It has nothing to do with the scale.getGram() call.

  • Great explanation of impedance and reactance! I wish my EE prof from almost 40 years ago was as entertaining and would’ve explained it as well as you. If he did, I might not have changed majors and might have stayed in EE. Even though it’s not new material for me, I did learn something and have a better understanding of it now. Thank you!

  • I was part of last year’s feeding frenzy, and not part of this year’s sale. The main reason: last year you could back-order, but not this year. half of what I ordered last year was back-ordered.

    I didn’t wait up until 3:00 am my time to get to the sale, but I did check it out in the morning when I got up. Just about everything I was interested in was already sold out, so I couldn’t order them. A couple mildly interesting “throw-in” things were still available, but their savings were only a couple dollars total, so it wasn’t worth placing an order just for them – I’ll throw them in when I make the next order.

    Curiously, I seem to remember a lot more things being sold out on Saturday than there are now. Maybe I’m imagining things, but I’m sure I’m not completely crazy: the post-mortem shows the Uno R3 SMD selling out in the first hour. But now here it is the next (business) day, and it shows 199 in stock? What’s up with that? Given the rate they were selling at, I’ll bet those 199 would’ve been gone had they been available.

No public wish lists :(