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October 21, 2011
lalalalalalalalaaaaaaa….. MAGIC SMOKE!
Product DD-12012 |
about 6 days ago
I don’t think a 14 day hold stock is anywhere reasonable. Your sidenote is only part of the problem - the bigger issue is I have stuff added to my cart to just check price totals all the time. If you were to do any sort of “hold” it would be after you enter in shipping, billing, and are about to confirm the purchase.
Is the fast internet speed process fair? no. Is there an easy way to fix it without invoking a giant mess? not that I can think of thus far.
Another way SF could do this. But it invokes different legal issues, is you purchase the product in advance, and depending on stock available, random orders are fulfilled. But there are strong legal problems with this - is it a lottery, sweepstakes etc.
Product PRT-12042 |
about 5 months ago
Shhhh! What are you doing? You’re giving away the secret to writing helpful posts!
Without the people who don’t read the datasheets, I wouldn’t be able to regurgitate passages from datasheets to sound intelligent!
News - Your August Caption Conte… |
about 7 months ago
Sparkfun RV - comes free with pet T. Rex.
Product ROB-11696 |
about 8 months ago
This type of motor is typically found in RC toys coupled to a cheap plastic gearbox. It basically is going to spin at a ridiculous rate with very little torque. (in this case 6600 RPM). Think: portable fans (those AA powered ones).
That Elecrow motor has a D shaft, and a metal gearbox coupled to alot more torque from the motor to start with. Higher input torque to high reduction ratio leads to low speed, high torque output (77 RPM, 5000 g-cm). Think: industrial equipment.
Not saying there’s anything wrong with either motor, but they’re just meant for different uses.
Product SEN-08883 |
about 9 months ago
The 5A version has a sensitivity of 185 mV.
Sensitivity on this is 185 mV/A with 21mV of noise. Page 5 of the datasheet. 20mA results in a rise of 3.7 mV. Since SF has enabled the noise filter, lets say this is reliably measurable (YMMV aka: no - probably not that reliably measureable).
That results in roughly 174mV at 20mA (at max gain of 47x). Arduinos can measure from 0 to 5V with 10 bits or 4.8mV. This ends up with roughly 30 measurements in 4 to 20mA. Not great precision.
Tl;dr: No. This is not the right way to measure the current output.
You can more easily measure your output with a precision resistor. Pass the current from the sensor through a resistor (say 100Ohm). That means at 4mA you have a voltage of 400mV across the resistor and at 20mA you get 2000mV across the resistor. You could measure this with the arduino directly, or if you wanted more precise measurements, measure it after amplification with an op amp or using an external adc.
News - SparkFun Gets a Subpoena |
about 2 years ago
To be clear - I mean after the case is closed - if you could notify the people involved. Obviously it wouldn’t really work out well for the investigators if you were to notify them if the case isn’t closed aye?
Also I wonder how many “scam-subpoenas” exist. What kind of verification methods exist to verify that a subpoena is real?
I’m a tad late to the comment party, but I’d just like to say that I appreciate how you guys (SF) handled this. As a resident of the state of Georgia, I got a bit touchy when I first read this. I - like most others - value my privacy, and don’t appreciate it when mass subpoenas are issued.
Two things I really appreciated about how you guys handled this.
1) You notified the public as soon as you were legally able to
2) You negotiated the subpoena to where only orders involved with the product were released
I have no idea if my information was released, but it would be great (if legally possible) if you could let the people involved know.
Anyway - thumbs up!
News - New Product Friday: More … |
about 2 years ago
“ You can use an FTDI to reprogram Mr. Roboto do do just about whatever you want.” Should read: “… to reprogram Mr. Roboto to do just about….”
No public wish lists :(