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  1. KrisBlueNZ

    Wireless Doorbell Mod Help!

    I agree exactly with what Harald said. You will have to modify the pushbutton to separate the contacts from the bulb or LED. You can then connect the contacts in parallel with the existing pushbutton in the new transmitter and it should work fine. But there's another issue: finding power for...
  2. KrisBlueNZ

    VGA to Sync on Green

    Are you talking about post #21 images #1 and #2? Do you mean the little negative spike at the start of each sync pulse? That's overshoot, it's probably not really there. It's probably a measurement artefact. The actual pulse sits at 0V.
  3. KrisBlueNZ

    VGA to Sync on Green

    That's very helpful. So it looks like the correct signal (post #23, image #1) is unipolar (doesn't go negative at all). Sync pulses are downwards to 0V, and the black level is around +0.3V. Peak brightness is about +0.9V. The signal at pin 11 (post #21 image #1) also looks right. Negative-going...
  4. KrisBlueNZ

    Night sensor

    The battery and the resistor are in series with each other; the load is also connected in series with them. Battery, resistor, and load all in series. But you obviously understand this.
  5. KrisBlueNZ

    pic programming help - controlling GSM to send message from PIC16F873A

    OK. There are lots of things you need to get right in hardware and software to make your PIC circuit work. Let's start with the hardware. You said that the GSM module has three signals: TXD, RXD and GND. And you said that you can send an SMS if you connect it to a PC and use the software they...
  6. KrisBlueNZ

    Night sensor

    You're right. My apologies. I was correcting your explanation, and lecturing the OP. I thought you were the OP. Not "a resistor across a voltage source"; a resistor IN SERIES WITH a voltage source. I think you KNOW what you mean; you just need to make sure that you SAY what you mean :-)
  7. KrisBlueNZ

    Threshold Circuit - Warning - I know practically nothing about building circuits

    The 555 timer contains two comparators with fixed threshold voltages and can be connected to operate as a Schmitt trigger. It can also drive LEDs and small motors directly. Google 555 Schmitt.
  8. KrisBlueNZ

    Panasonic NV-HD650A sound

    "Weird sound" isn't very specific. Can you capture the sound with a computer and upload it to a file sharing site? (I don't know if it's worth it. I won't be able to help. It's just a suggestion.)
  9. KrisBlueNZ

    Increase volume of simple ribbon synth?

    That two-transistor relaxation oscillator produces a very narrow output pulse. It's possible to widen it; I think one way is to add a small resistor (try 100 ohms) in series with the 0.01 µF capacitor.
  10. KrisBlueNZ

    Night sensor

    Not necessarily. An LED needs to be driven with a current, not a voltage. If you connect a red LED (for example) across a voltage source, for example an adjustable voltage regulator, and set the voltage to 1.5V, the LED will light dimly, or not at all. If you slowly increase the voltage from...
  11. KrisBlueNZ

    pic programming help - controlling GSM to send message from PIC16F873A

    LOL! Thanks Steve. I wasn't sure how to respond! I was thinking that perhaps I should offer to fly over to his place and get it working for him.
  12. KrisBlueNZ

    LED application question

    OK, yes, this unit is going to be a bit tricky to drive. The four individually accessible LEDs are simple enough to drive. You can drive them directly from a PIC pin, with a current limiting resistor. Have a look in the Tutorials section for information on how to connect LEDs and current...
  13. KrisBlueNZ

    555's are terrible, no they're not, yes they are, no they're not

    I'm a little late on this thread but here's my $0.02 on the 555 timer. It's convenient for several types of applications. Astables, monostables, and Schmitt triggers, mainly. Its output is able to drive LEDs and relays directly. In some types of applications, there is no single IC that would be...
  14. KrisBlueNZ

    Automated Sliding Door

    OK cool. I'm looking forward to it.
  15. KrisBlueNZ

    VGA to Sync on Green

    Yes, some oscilloscope traces would be very helpful. I would like to see the green video, horizontal sync and vertical sync waveforms from the VGA card. You don't need to use the monitor at all for that test. I would also like to see the waveform on the composite output of the circuit without...
  16. KrisBlueNZ

    pic programming help - controlling GSM to send message from PIC16F873A

    I'm not familiar with the PIC's serial port architecture so I don't know whether your other initialisation code is correct or not, but there is an obvious bug here: Each time you place a character into the USART's transmit register (TXREG), you have to wait until the USART has transferred it...
  17. KrisBlueNZ

    FP DD605 f2 code ?

    Have you done your due Google diligence? Here's one hit for a start: http://www.fixya.com/tags/fisher_paykel_dd605
  18. KrisBlueNZ

    pic programming help - controlling GSM to send message from PIC16F873A

    There's not much point trying new, untested code on a PIC. If it doesn't work, there are dozens of possible reasons, and it's hard to debug. Test your GSM modem first using a PC and typing the AT commands on the keyboard. That will allow you to try different baud rates and find out what baud...
  19. KrisBlueNZ

    Automated Sliding Door

    First, post some photos. The files must be smaller than 145 kilobytes, if they're JPG files, or smaller than 95 kilobytes for other image file types. Click Go Advanced and click the paper clip icon on the top row of the toolbar. The upload dialogue box appears. Click Browse and select the file...
  20. KrisBlueNZ

    Panasonic ct-27g7df .

    Hi and welcome to Electronics Point :-) I downloaded the service manual from electrotanya. Here is the section with the front panel pushbuttons: This set uses a common and simple trick to read the front panel pushbuttons using just one or two pins on the main MCU (microcontroller). A signal...
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