Recent Posts

Pages: [1] 2 3 ... 10
Deutsch / Re: Mal wieder ein Display
Last post by Fipsi - Today at 07:43 am
Okay.. jetzt bin ihc auf putty umgestiegen und das Ergebnis ist immer noch gähnende leere.. bin ich so doof? Ich probier mal nen anderen Atmega, aber daran dürft's normal nicht liegen, weil der beim letzen mal noch problemlos ging.


Thanks! That works
Who would have thought I needed to add "pt".

Although CTL+ + does sorta fix those problems, it I don't like how the upscaled images look
The code is working fine
No it isn't. The code is lousy. I can tell that without looking at it

Checked my code twice.
you probably haven't checked it properly at all. But, if you will not post it, who would ever know?
Hmm, gonna have to review my code to see how I handled rising or falling. It's on a different computer tho.
Yes that's better, assuming -5V is ground.

If you have a 'scope, you probably have a multimeter too.   Both leads on a meter are floating, so there's no need to ground the negative lead.    Use a meter instead of the 'scope and your 1st schematic will work fine (as long as you have enough current to get a measurable voltage across the resistor).

Or, you can connect the meter in series (in place of the resistor) and measure current directly.

Or, if you have a dual-trace 'scope there is usually a differential mode where you can connect one probe to each side of the resistor and measure the difference between each end.

Bar Sport / Re: digital travel case - grea...
Last post by Chagrin - Today at 07:03 am
No point in knowing that your luggage is in vancouver when you are in hawaii.
Yeah but if you spent ~$200 on a piece of luggage you'd want to know where it was at all times. ;)
Yes, low is approximately ground, or approximately zero volts.   An output pin can "sink" up to 40mA.
Project Guidance / Re: Rocket gyro or accel
Last post by Chagrin - Today at 06:48 am
The gyro reports the rate of the rocket's spin. If your rocket nosed over sharply at its apex then it'd work but I don't think that's typical of any rocket.

Very complete discussion of the problem, as pertains to rockets, here:

For an incomplete discussion, or if you flunked Algebra, then you'd get a barometric pressure sensor (e.g. BMP085) and wait for a steady altitude reading to denote your apogee.

Project Guidance / Re: Rocket gyro or accel
Last post by bobcousins - Today at 06:45 am
Sounds like an interesting project, I used to fly some model rockets, so I am officially an amateur rocket scientist  :smiley-cool:

All the motion sensors have limitations, which you have to allow for. The flaws can be compensated by combining the different sensors (sensor fusion).

Accelerometer tells you acceleration, that includes gravity though, and you can't tell the difference between gravity and acceleration unless you know which way is "up". Gyros can sense change in direction. With 6 axes (accelerometer+gyro) you can do "inertial guidance", I guess you have to calibrate the initial state.

If you are not doing any guidance, logging raw data would be easiest, and crunch the data on a PC afterwards. I'm not sure what data rate you would need to get a decent track, depends on your rocket :)
General Electronics / Does a pin act as a ground whe...
Last post by h4344 - Today at 06:45 am
Im just wondering does a pin on an arduino act like a ground when its set to low? Using a NPN transistor the gate opens if i connect the base to a ground pin or set one of the digital pins to "LOW".
Pages: [1] 2 3 ... 10