I know this is not the right place to post and I truly apologize. If someone can send me in the right direction I would really appreciate it or maybe help me. I want to run POE over a distance of between 1 kilometer to 12 kilometer (I know this is very long). Would POE work for me or am I wasting my time researching this. What I want to do is have a single power and communication point to connect Arduino's every 100 meter on a single cable (CAT5 or similar) and communicate over I2C to a single master Arduino unit. I am stuck at this. Thanks again for hearing me out, pointing me in the right direction or answering my question for me. And sorry for my horrible english :-)
there is a dedicated Arduino forum, https://arduino.stackexchange.com/ which you may prefer.
Arduino uno draws around 45 mA. Cat5e is 0.188ohm/meter, so the cable has a resistance of 376 ohm (one kilometer power, one kilometer ground). Hm, this is not that impossible after all :) you lose like 17V on 1 km of cable.
However if you have an arduino at every 100 meter, that means 120 Arduino, a solid 5.4A current draw. Maximum allowed current per conductor is 0.577A on a cat5 cable, so this won't work on 5V.
POE can make this a little easier, as it runs at up to 48V. By increasing the voltage, it is possible to use thinner wires, since less current at higher voltage carries the same power. PoE can wire 60W of power over 100 meters (with serious losses due to the thin copper wires in the Cat5e cable). So I would say, although the idea is insane (no offense :)) but actually it is possible to make it working.
However you can't do I2C on such a long cable. You have to go for at least RS485, and use it at a very low speed, say, 300 BPS if you want to have 12km.
Is there a chance to learn the problem you're trying to solve? There could have been much better solutions than 12km of wire. That is a serious cost in copper, not to mention the cost of a good PoE adapters. For a 12km long wire, you have to have very serious overvoltage protection, too. Probably a radio link and a battery-operated device would be a better choice, no?
Related
I'm building a cosplay prop for a friend that uses an arudunio Uno. The UNO will be kept inside a black PVC box with little ventilation and taken to comic cons. So it's going to get hot at times. I've never really built gaming PCs or anything with batteries and I'm not sure what temperatures are ideal to run at so my guesses are just based on a google search.
My question is:
If I place a temperature sensor next to the UNO and program it to start a fan at a given temperature, What temperature would be a good choice?
I was thinking 35 degrees with an alarm going off at 70 degrees telling him to turn it off.
Also, there will be two other batteries one 3.7V Li ion phone battery that powers the chips and a small audio amp with a 18-volt (May change) drill battery powering a DC motor. Both in different locations.
For this, I was thinking I would set a larger fan to start at 30 degrees with an alarm at 55.
FYI this will be programmed on a separate ATTINY chip.
I would recommend keeping it below 125C maximum (that is the ATmega 328p's maximum temperature rating). However, I have never seen an UNO get that hot. If you are concerned though, aim for as cool as possible with a maximum temperature of about 80C
I am making a system for measuring whether or not there is vacuum present in big steel containers. They are located up to 100 meters from the control cabinet.
The question is, how many SPI sensors can I successfully use at the same time with an Arduino Mega?
I have two main concerns, and there are probably more things I didn't think about.
Signal strength
The shared lines for CLK, MOSI and MISO will need to be split up at several junction boxes and led to the different sensors. Since the voltage out from the Arduino is fixed, I'm fearing instability because the signal is weaker for some sensors, has someone done something similar? What is the greatest acceptable voltage loss for these lines to an ordinary sensor?
Processing
Will the SPI library be fine coping with this many sensors?
The refresh rate can be set to extremely low, thinking 0.3Hz.
The alternative to all this is to go for 4-20mA sensors and have a 0-5V converter circuit for each sensor, near the controller.
Any inputs would be greatly appreciated!
i have a little 2,4" tft touch display, and i want to display Information like Temperature of the CPU and the GPU, and the usage of the CPU cores. i tried getting the temperature with wmic and the MSAcip_ThermalZoneTemperature. but my system does not support that. Could someone tell me a way to get the Temperature and the other information without buying any extra hardware? My Mainboard: Asus M5A78L/USB3 (https://www.asus.com/Motherboards/M5A78LUSB3/)
Thanks, and have a great day!
Without extra hardware, the best way I can think of is to write a program for your computer that is able to pick up temperature statistics from your mainboard, then have that speak to your Arduino via Serial over USB.
The other option I can think of would involve finding out where the temperature probes on your mainboard live and physically tapping into those and reverse engineering how they work. However, this stands a very high chance of voiding warranties and ruining your board.
I have a weird problem. I am currently building a BB-8. Therefore, I am using an Arduino Uno. On top, I have stacked an Adafruit Motor Shield v2.3 and, again, on top of this, I have stacked the Sparkfun USB Host Shield. The Arduino is powered by a 9V-Block battery, the motors are powered separately by two 18650 Li-Ion batteries. To control the two Pololu motors, which have a stall current of 1.6 amps each, I use a Xbox 360 wireless controller, where the receiver is connected to the USB Host Shield.
Now to my problem. Every seems to work fine, until i cover everything with a styrofoam hemisphere. Yes, you've read right. If that happens, the controller signals is lost and does not connect again, unless I restart the Arduino. I have uploaded a small video on youtube, where you can see the problem.
I guess, this is a power problem, since this issue does not occur, when I connect the Xbox receiver to my Mac. Has anyone an idea, how to solve this problem?
I already tried another power source. And the USB host shield should give enough power, since the specs are saying, that 500 mA is no problem, and hit is exactly the USB 2.0 spec. The combination of the shield shouldn't be a problem, too. I carefully chose this shields, because the motor shield is just using the pins A4 and A5, the USB host shield is using some of the digital pins, so I think there is no interference.
Thank you for your help.
EDIT
I have tested it a bit more now and i think i can reduce the probable reasons. First, i tried some other power supplies, from AA batteries on the VIN pin to external power adaptors. Next, i tried other xbox receivers and controllers. I also tried a playstation 3 controller with a Bluetooth dongle. Nothing solved the problem. I also covered the Arduino with other things than styrofoam, like a garbage can, cardboard and some metal box. This worked, so the problem was only with styrofoam. Now i haven't covered the Arduino, but i slowly got closer. About 20 cm from the Arduino, it stopped working. My clue: static electricity. Do you think this can be a problem? And if yes, how can i solve this?
Try use single battery + separate voltage regulators for every load. Otherwise if one of the batteries discharges while other are ok, it can take all power of the system, something like short-circuit. Also you can receive a trouble if do error in ground connections.
Select good battery, which can provide enough power. If cant find a battery which can supply enough current think about using low current batteries in series to achieve extra voltage. Then reduce voltage using dc-dc step down converter.
For example if you have a battery of 24V which provides 1A (power p1 = 24*1). It can provide 5A if reduce the voltage to 5V using dc-dc. (power p2 = 5*5). Because p1*h=p2, where [h=0.8 - efficiency].
So, I solved the problem. As is mentioned in my question, the problem was static electricity. I primed the styrofoam sphere with some special primer to make the styrofoam a little more stable and so on. That's it. Luckily I didn't touch the Arduino with the sphere. I think it would have damaged the Arduino.
Well I've looked and looked and just cant find data on the max current of the 5 v output (or even a suggested reasonable max)
They all mention 50 mA for the 3.3v output.
Looking at the chip it's a smaller board than the Arduino Uno so I don't want to pop it.
I assume someone will know the max current that the regulator on this board can handle and surmise what the 5v current out could be? Thanks in advance!
EDIT: The regulator / board 5v pin out, not chip related.
EDIT: Assuming supply is from the 12v power adapter.
The schematic shows a NCP1117ST50T3G. The datasheet shows 1500mA (typical).
Note that you may not actually be able to draw that at the higher end of the input voltage range since the Arduino may not provide sufficient heatsinking, needed since the regulator will shut down if it gets too hot (and the regulator will melt down if it doesn't shut down).
Also note that the traces on the board may not be designed to allow that much current to flow safely, and you could end up damaging the board itself regardless.
I'm going on record that you can put any amperage as input as long as the voltage in within range. So, if you have a 5V 200A high power input you are still fine. Now, If you have a short, you're cooked. But a properly designed circuit will draw what it needs and nothing more.
Hyperbole. I know absolutely nothing about this topic. I'm hoping a lot of people will call me names and one of those will correct me with a correct electrical engineering based answer. Either my view is correct or it isn't.