The Kontraptionist

Member Since: July 1, 2010

Country: United States

  • Adafruit would have put a 26 cent regulator and an I2C level shifter on their version of this board… Just saying. Seriously guys, the purpose of a breakout board isn’t always just to solve the problem of people not being able to solder surface mount. How much does a PCA9306 cost in 250 count? 54 cents. To make the board a ‘whatever you throw at it’ voltage. The value of improvements like these are huge, and now you can plug it in to you Edison OR your Uno. With no extra crap!

  • Yeah a sure heart attack. How many hundred joules are we talking here? By your estimates, assuming a USB port, 5v, 500ma. Or are you assuming that the ground lead of the computer is connected to the hot side of the power outlet? I hear this does happen, though I’m not sure if I’ve heard of it going unnoticed for long. You bring up a good point. Spark fun should look in to this.

  • I’d be a little careful about calling the level shifting circuit “proper” - the resistors in the circuit are 1K - 1K to +5 and +3V3. That’s a pretty low impedance line, especially considering that the Arduino Pro has 1K resistors on the TX and RX lines (why is this by the way???) What bothers me is that the stand-alone level shifter (BOB-08745) has 10K resistors. I substituted 10K (Ask me how fun soldering was with only a regular iron and tweezers) and it at least works now with the Arduino Pro, but it barely pulls “LOW” to 1V

    I should say it works FINE with a Leonardo (and probably the Uno too) because they lack the resistors on RX and TX.

  • Anybody design a 3D printable case for these yet? Also, Sparkfun, suggestion to change the LEDs to side-shining? My two cents!

  • Just wondering if that ATMega328 is rad-hard? :-)

  • The emitter current limiting resistor on the analog versions that are shipping October 2012 are measuring to be 100 ohms. The sensors are actually running pretty warm. The emitters are drawing 34mA at 5V - but a perfect 20mA at 3V3. I know the datasheet has absolute maximum ratings of 50mA, but… I have four of them runing at 5V and they’re all running just over 100ºF. Are we sure this is OK?

  • You’ll never see open firmware. See licensing nightmare rant above. My experience is similar. Imaging technology is so locked down that it’s basically impossible to do anything outside of going to Best Buy and buying a camera. Plan works perfectly.

  • Love it how the Atmel on the shield completely smokes the shoes off the little chip on the Arduino. Why not leave the separate Arduino out of the picture completely? I guess it’s a different compiler? (for the 32 bit?)

  • The MP3 Player Shield has been tested as working with an Arduino Pro 3.3V on both LiPoly and USB programmer power and with an Arduino Uno with no modifications to hardware or code on either, save from the addition of the “9” in !card.init(SPI_FULL_SPEED,9)

    How it will perform on a partially charged battery is another issue that remains to be seen and will depend on the dropout of the voltage regulators, but for now 3.3V performance seems solid and there are no drops in audio at 8 MHz. FYI the Arduino Pro 3.3V doesn’t have 3.3V and 5V pins, just VCC and VCC.

  • Hi! OK, so most important piece of info that needs to be repeated, as per SDFAT Readme.txt

    Nobody has to modify any pin definitions in the libraries! (Rejoice!)

    If you have a shield like the SparkFun MP3 shield that uses pin 9 for chip select you would change the line: card.init(SPI_FULL_SPEED) to card.init(SPI_FULL_SPEED,9)

    This way you don’t have to go and change SDFat every single time. Seems like the RIGHT way to do it..

    Also, as for the line-out protection, just don’t connect the speaker/headphone common pin to ground in any way shape or form, like powering from USB and plugging the shield’s 3.5 mm plug in to the PC’s line-in. Figure 3.2 of “Line Out Information” shows a simple 4 resistor two capacitor setup which should be considered for implementation on the next revision of the board.

No public wish lists :(