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  1. (*steve*)

    Trouble getting enough power to LED strip

    There is also a limit on how much current you can draw from the 5V of the Arduino. What is powering the Arduino? What voltage?
  2. (*steve*)

    Understanding impedance

    The voltage divider formed by the output and input impedances allow you to calculate the voltage seen at the input. For signal applications it is often desirable that the input impedance is high compared to the source impedance in order not to load down the source.
  3. (*steve*)

    Understanding impedance

    The first thing is that the non-resistive portion of impedance is frequency dependent, so the impedance is given at the operating frequency. If you have some device with an unloaded output of x volts and an impedance of y ohms driving an input with an impedance of z ohms, the voltage seen by...
  4. (*steve*)

    LED supplier ?

    Well, we did go to Mendelson's twice :-D Great fun. Should we mention when we tried to steal that car? edit: Who is this man?
  5. (*steve*)

    Surge monitor

    You could also pass the 50/60 Hz through a notch filter then see what's left. If you look for events which cross a threshold, you can count them.
  6. (*steve*)

    Sensor choice for pond water depth

    If using a method involving conduction, I'd AC couple the signal to the probe. This will reduce problems with electrolysis. If you have the signal probe deepest in the pool and a series of probes each shorter than the previous one, you should be able to get an indication of the level. With a...
  7. (*steve*)

    sim800a gsm module not working

    It also might be worth checking the voltage levels required. These days TTL levels are usually fine, but that's technically not RS232, so the requirements might differ.
  8. (*steve*)

    Have I bricked my Arduino Uno? Problems with uploading to board

    If you have 2 Arduinos you can use one to program the other via the ISP header. This will allow you to download the firmware again. Beware that you may have to override the reset on the one doing the programming. The sketch, but not the information is one of the samples.
  9. (*steve*)

    Design assistance needed

    OK, now you need to find example code for the other devices you have and make sure you can operate them on their own. I don't know exactly what they are, so you may either need to provide more information or do the leg work yourself. Starting with the distance device first (maybe), if this is...
  10. (*steve*)

    Design assistance needed

    Ok, so do you understand how the code works? Can you change it to flash faster and slower?
  11. (*steve*)

    Best solder to use

    There are a plethora of lead free solders in the world. If you're using lead free solder you really need to know what it's made of and what its characteristics are. It may be as simple as it having a higher melting point, looking a little dull, and being more brittle. But there are some that...
  12. (*steve*)

    Circuit Protection For Inputs In Hostile Environment

    +1 If you're going the pair of diodes approach, Schottky diodes are better, and a resistor before and after them will limit the current through them as well as ensuring most goes through the external diodes. One of the other problems with using diodes this way is that they can shunt excess...
  13. (*steve*)

    Circuit Protection For Inputs In Hostile Environment

    The inputs already have their own diode protection. For minimal parts count you could just add a simple series resistance that is sufficient to limit the current through this protection. There are packages that contain multiple resistors, so you may only need one device per 4 or 8 inputs.
  14. (*steve*)

    Circuit Protection For Inputs In Hostile Environment

    It depends on what you're trying to protect the input from, the nature of the input, the impedance of the usual source, and the requirements for handling fast edges. For example, what you need is vastly different if you're trying to protect against direct lightning strike vs a line level output...
  15. (*steve*)

    Solder issue.

    You can also parallel strips or physically wire the high current paths.
  16. (*steve*)

    Design assistance needed

    Sure. We can help you learn how to write the code. Have you got everything set up and tested using the LED flashing example?
  17. (*steve*)

    Design assistance needed

    I recommend you set up the software on your PC and start working through the examples. The Arduino web site will help with many of your basic questions. There are also lots of YouTube videos which will help setting up and explaining stuff. Perhaps your goal for the first day or so is to get...
  18. (*steve*)

    Battery temperature sensor

    You can't measure the temperature without measuring the temperature.
  19. (*steve*)

    Design assistance needed

    Pretty much wherever you want it to. How much stuff have you done with your Arduino already? How good are you at programming in C++? Have you run through any of the examples and tutorials that come with the Arduino environment? How long do you have to learn to use everything you have before...
  20. (*steve*)

    LED Matrix 5x7

    The first calculation would be power (i.e. energy over time). So 1/7 vs 1/10 - change from 150mA to 105mA. The change in the pulse width is a more complex calculation involving the thermal capacity of the device. I don't have time to do it at present, but if you look at other LED datasheets...
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