You can post a link to the datasheet for the parts you use.
No a dataline input is a logic input, (almost) no current is required
Ah yes. Well the lower rate will cover more distance.
No. The dataline is a 0-5vDC input on the LED side of things, and you should power it with 5vDC logic levels.
That is for the power lines. Since voltage drop of cables is absolute, you can use the same thickness of cable with over double the length compared to 12vDC Power cables. Which are generally better when they are thicker since they will have less voltage drop.
A longer cable is just as much or in most cases even more of a problem, but for completely different reasons. For a dataline a thinner cable is better since it will have less capacitance. Capacitance is a phenomena where electrons pile up on the surface of the metal making the cable act like a capacitor, which causes the square data signal wave to become more like a saw wave and that destroys the timing.
Did you try with a thin cable ?
Anyway if you can stick a twisted pair cable (for the data) through the conduit and 2 thick power line for the 24v, then all you need at the other end is a 5v regulator and a MAX485 transceiver and a terminating resistor, and it will for sure work. (if you put another MAX485 transceiver near the UNO and wire the thing properly.
The resistor protects the UNO against shorts and high current and bounce. 50' of cable will have quite a bit of resistance already, and to be honest the resistor also has extra capacitance.
There is a way with which you can increase and decrease the data signal voltage, and that should help but need high speed CMOS gates from the 4000 series, something like the 40109 looks appropriate but i could find a speed reference in the datasheet. Still as long as it provides a straight transition it will probably be fast enough and might work, but i personally use the MAX485 chips, but they require a twsited pair.
Will try all of the above solutions when I return from my trip and see how it goes. I will try to see if I can find out how they are already doing it with no changes to the far side of the setup. No hardware of than the lights exist there. Thanks again for the good ideas - Have a great holiday!
Sorry @mikedb I'd be very surprised if a logic level converter will help. Voltage is not the main issue, frequency and the ability to drive a long piece of wire correctly are. Driving something like this requires impedance matching and something capable of charging and discharging the cable capacitance, I'd be very surprised if a level converter can do either of those things.
I'm holding off offering anything more helpful because @va_arduino has yet to provide the requested information. For me I'd like to see a schematic of what is proposed and some photos of the existing setup plus links to the hardware. What is, for example, a T8000?
We've not even been provided with a schematic of the proposed circuit with a TIP120.
I might or might not have anything useful to offer, but with the information currently provided all I can offer are general suggestions.
Well one approach could be to increase the voltage of the data-line and reduce it down again at the other end. Reducing the effect of the capacitance (I think), but as i have stated before, MAX485 transceivers are a better solution with which i have done a lot of real world application with and covered distance up to 50 meters (though generally not more than 25 meters, which is of course in most cases already quite a lot. Personally i don't see why there can not be any receiving circuitry, and even wireless WiFi is an option. The OP has stated that this is not possible, but that running a conduit through the ground is ?! If you can bury a piece of conduit, you can bury a waterproof box !
Increasing the voltage at the transmit end then reducing it back to what you actually want at the receiver reduces noise picked up along the cable as the noise picked up is the same regardless of the signal level, so if you have a signal that is higher than you want then when you reduce it back to what you need you also reduce the noise by the same amount.
The T8000 info was provided in an earlier posting via URL. As mentioned previously I still need to check on upload ability - however I am currently travelling for the next few days as I stated in my post last night.
The noise in my experience in so much the issue, the capacitance is. As i suggested before just have a 7400 series TTL chip at either end (ideally a Schmitt-trigger) might already improve things sufficiently. Increasing the voltage level is worth a go, though i have no clear idea on how this affects the effects of capacitance on the wave-shape. Noise might be a bigger issue if there is an AC-cable right next to the data line. It all depends on the cable through the conduit and other physical layout conditions, i guess we will have to wait.
Yes, that is correct. It drives it fine. It is not known whether or not it includes components that are found in the signal booster I purchased, but the completed T8000 does work out of the box.
A conduit is in place and cannot be snaked nor changed. I can only reuses the existing signal wire. And there is not place nor reason to bury a waterproof box. A solution has been found as indicated in my prior post that uses a signal booster at the point where the Arduino is installed. My application and use scenario is governed by strict rules by a manufacturer, ASTM, and county inspectors. There is no place or permission to modify the device on the receiving end. Yes, anything is possible. But modifying a concrete pour for a very large machine and structure that has been in place for decades is not an option. Instead, the solution used is simple and works. Thank you for your input.
Nice find, @va_arduino ! I’ll keep that little gem for future reference. Thanks for returning to post your solution, I’m sure it will be useful for others in the future.
Hi, @va_arduino
Good that you have found a solution.
Can give you a tip about writing post.
To make them easily read, put what you need to say in point form of separate paragraphs.
The more readable, the more responses you will get.
