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I want to make a robot using 12 volt motors, the only problem i have is that the highest voltage from a GPIO pin is only 5 volts, and if i hook a 12 volt motor up to a 5 volt pin the motor would still try to suck 12 volts out of the 5 volt pin and could possibly (most likely) fry my raspberry pi. WHAT SHOULD I DO ?!?!
You cannot use just your raspberry pi as a power source. In your case you need a 12v battery, 12v to 5v dc-dc adapter to power your raspberry pi and then a transistor or driver module to power your robot
Use a transistor as a switch. So a little voltage will drive a bigger one.
Better, use some motor driver wich will accept 5V and give whatever power your motor need. This is a more conveniant way, as the circuit is already done, only need to plug motor on the driver, driver to raspberry.
Better again, ask on Electrical Engineering, as this question is more about electronic than programming.
Note : the components will depend on your motor specs, the number of motors you need, and the type of motor (stepper motor ?)
Note 2 : you will obviously need a 12V power supply to power your motor.
Some componenets can transform 5V to 12V, but you can't rely on the raspberry power supply to provide enough power for motors, even with such a converter. Use a secondary power supply if possible.
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I am quite stuck on a board, or something that could fit my needs.
I made a dual Projector 3D System at home, like this : http://www.cinema3dglass.com/Dual_projector_3D_polarization_system.php
And the HDMI can have different (8) formats(Left Right, Above Below, ect..) all here: https://www.tridef.com/user-guide/3d-file-formats
So the needed images on the incoming HDMI port can ble placed like above, and I need to split them on two separate HDMI outputs according to the format, so I can plug them into the projectors.
Basically I need a device that is in the first image in the first link above title: "HDMI Distribution Amplifier & EDID Emulator"
I know an Arduino can't handle this amount of processing, because I overloaded it with simlier tasks.
Can anyone Help me where to start? I foud Panda development board but that's too expensive.
Or if there is a not owerly expensive device existing for this task, I could buy that.
I manadged to use the system from Tridef 3D but that's hard to get working.
I'd like my device to get the input from a Chromecast 2.0, but if it's not possible a normal player 'll do it.
I found some devices called HDMI Demultiplexer they simply cut one half of the input, but that's quite expensieve, for 260$ and two would be needed.
Help me please.
Thanks in advance.
From the HDMI specification at page 56 the transfer/interconnection looks like this:
I would start with interleaved left/right format where even pixels are left and odd pixels are right because there is high chance that it does not need any FIFO. If you want standard left/right then you need single line FIFO for each channel and for up/down full image FIFO. In case variable clock is supported by your HW then this simplified example should work:
You need to add H/V sync decoder from Channel0 to reset the binary counter. Binary counter counts which data address is being processed. The single data-line to the AND gates should be D1 half of the input clock but not entirely you need to toggle between D0 and D1 depends in the timing of data processed (for pixels it would be D1 and for other data it would be D0) that is the variable clock I mentioned before. The comparator just compares the address against predefined constants (like half of line for non interleaved left/right format or detect even odd for interleaved format but both must take +/- other data offsets) beware the transfer is on bits not Bytes so the address will be multiplied by number of bits per data chunk ... The gates just toggle clock between left and right part. LATCHES make sure output signal will be not mixed and also boost the signal.
I would start with oscilloscope measurements of the channels so you can see how the data is transfered and then experiment-ate. If you use FPGA then you do not need to make any changes to the board while ecxperimentating with configurations as the circuit will be solely inside FPGA.
If variable clock is not supported then you need to use FIFO and or RAM to store the full line/image and then send the appropriate parts to their connectors. For that you most likely need full decoding capability so use the SIL9134 + SIL9135. Halving resolution will introduce timing problems because you will need more time to send half speed half frame then the full speed full frame (the auxiliary and sync data is copied not halved). If the sending has big enough gaps you could fit the missing time there but again not all HW can support it losing sync/flickering/etc. In such case you could change the resolution to a bit smaller (after halving) to fit in the send time ... or enlarge thi full resolution input (in x axis).
Good luck with your quest.
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There is another question with this same title, but the question is asked differently than what's troubling me, and the answer is not sufficient.
The most prominent analogies I hear to explain bandwidth are the highway example, and the pipe example. In the highway example, bandwidth is the amount of cars that can drive on the highway in a given amount of time, and in the pipe its an amount of water that can flow through.
My question is - by measuring by cars per second, or liters per second, does that mean that a longer highway, pipe or copper wire has a higher bandwidth than a shorter one? That seems strange to me.
Wouldn't it make more sense to give the highway bandwidth as the amount of lanes it has - irrespective of a unit of time? It just makes more sense to me and is simpler to say that the pipe is "1 foot in diameter" rather than "it carries 100 litres per second".
Why do we measure bandwidth in bits per second and not just in bits?
"My question is - by measuring by cars per second, or liters per second, does that mean that a longer highway, pipe or copper wire has a higher bandwidth than a shorter one?"
No!
Bandwidth is not about how many cars can fit on the road. It's about how many cars can pass a point on the road during a certain time. How many cars per second can pass under a bridge, for example.
No, it wouldn't. You quote a highway in terms of lanes, because it's more understandable, and a reasonable approximation to assume 4 lanes = 4x as much traffic. But even then, you might have a traffic jam, and then 4 lanes is 'transmitting' fewer cars per minute than it would otherwise.
With a hose pipe, the width of the pipe is the speed of transmission if you assume the same water pressure.
These assumptions don't apply to communications - when I'm transmitting 'a bit' nothing physical is moving *. A 'bit' is the smallest piece that 'information' can be broken down into, and in order to transmit it, something needs to change.
If I turn on my torch and shine it at you, I've sent one 'message' (my torch is on). To send you anything more detailed, I would need to turn it off and on again - morse code is an example of doing this. The pattern of switching it off and on gives you some letters. How fast I can switch it off and on again, is how fast I can send a message.
So it is with bandwidth. I need to change things to communicate. If I can change things faster, I can communicate faster.
"bits" would be a measure of the number of torches I own. Bits per second is how fast I can flick them on and off to send a message.
* Electrons and photons do move, as does air to carry sound. But the signal isn't the thing moving - I don't have to move an atom of air from my mouth to your ear to 'talk' to you, the wave propagates through the medium.
Looking for some help to be honest, This is not my area of knoladge atall.
Ive read around the question of powering my Pi with a battery, now I nabbed one of these guys for my phone
http://www.amazon.co.uk/13000mAh-Portable-External-Technology-Motorola-Black/dp/B00BQ5KHJW/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1420826597&sr=1-1-catcorr&keywords=anker+astro+e4
Incase the link dies in the future;
Item model number: AK-79AN13K2-BA
Anker® 2nd Gen Astro E4 13000mAh 2-Port (3A Output) Fast
Max 3A Out
5V Out
Now, from what i've read there have been mixed notes of, don't use batterys, only use this battery, don't do this, don't exeed this magical number ( which was differant each time ). so any help would be grately needed. If i was to power my pi via this thing. im I going to get a poof of smoke and need to replace the poor pi :(
A raspberry Pi is powered via USB, which means that it simply takes the 5V supplied via USB to run. As long as your current source is stable (ie. it doesn't change when you draw current from it), no device will care whether it is a battery or a switching power supply. Now, a bare raspberry Pi B uses less than 2W of power, 2W/5V = 0.4A = 400mA, so if that battery pack lives up to its specification, you are going to be fine. The device is spec'ed to provide 13000mAh, so at a constant current of 400mA, this would last you more than 32 hours.
Now, most people attach something to the raspberry, and that something will also draw power, but just add that power to the calculations above, to see if it's going to work out.
I'm new to Raspberry Pi and I don't understand about electricity. I bought a Raspberry B+ today and a 5V 3A power supply, but I'm afraid to connect it because in several places I read about using 5V 2A power supplies. I believe that only higher voltages can damage the Pi but, since I don't know about Amp, I don't know if this is true for 3A too.
My ideia is create a mini-personal server in my home, running Pidora. For data, I have a 1 Tb external USB drive with no external power supply (Seagate model SRD00F1).
My questions are:
can I use the 5V 3A power supply on Raspberry Pi B+ without damage it?
this power supply is compatible with my external USB drive to keep it on safely?
Thank you!
The Raspberry Pi FAQ says that the B+ uses between 0.7 and 1.0 amps, and suggest a 1.2 amp power supply as a minimum.
Using a power supply with a higher amperage rating will not harm your Raspberry Pi. Devices only draw as much current (amperage) as they need. Any additional capacity is unused.
This is where your question about the external hard drive comes in. If you see in the FAQ, they suggest that you might want a larger power supply if you use all of the USB ports. Every USB device you plug in is going to draw more current. To figure out how much you need, you just add up the requirements of all of the devices like so:
Raspberry Pi = 0.7-1.0A
Mouse/Keyboard = 0.5A
Hard Drive = 1.0A
========================
TOTAL = 2.5A
(These numbers are all fake... be sure to check the requirements for your actual devices.)
So if your devices total 2.5A then a 3A supply will handle all of these plus some room for expansion. If all of your devices total 3.5A, maybe you need to consider a bigger one.
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I have a Xeon phi coprocessor 7120P.
When i run micinfo, i see board SKU to be C0PRQ-7120 P/A/X/D.
I notice that the SMC HW Revision states Product 300W Passive CS and i read on tomshardware that P stands for passive cooling for the intel xeon phi familiy devices.
Is this it or is there any other way to tell which device i have on my system 7120 P/A/X or D?
From the specs given on ark.intel.com, all four devices appear to be same.
Can some one elaborate on what are the actual differences between these devices.
The A/P/X/D variants of the Intel Xeon Phi Coprocessor 7120 are different form factors with different cooling. The codes are: A = active, that is, with fan; P = passive, that is, air stream needs to be supplied from chassis fans; D = dense, special form factor for very dense design; X is a special form factor for manufacturers that want to make their individual designs.
The CPU and memory of these coprocessor versions is the same in all four cases.
Cheers,
-michael