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  1. KrisBlueNZ

    Help Getting Started with PIC Microcontrollers

    If Microchip have removed MPLAB 8 from their downloads, maybe they want to force everyone to use MPLAB X. You may be able to find it elsewhere though. Perhaps through an anonymous file-sharing system that I probably shouldn't mention by name, or through some independent site. Re PICkit 3...
  2. KrisBlueNZ

    help over microcontroller code

    He wasn't using an array. He was using a separate variable that would be incremented each time through the loop but never used! I think the most efficient loop (including on baseline PICs) would be byte c; while ((c = *cmd++) != '\0') uart_tx(c);
  3. KrisBlueNZ

    Need help with I hope simple project!

    If you do get another headlight and take it apart, feel free to post photos here. We may be able to suggest a way to hack into it to determine which mode it's in, or change it so you can set the mode with an external switch.
  4. KrisBlueNZ

    Help Getting Started with PIC Microcontrollers

    There is at least one BASIC compiler for the PIC: PICBASIC (see http://melabs.com/) I haven't tried it or looked into it, but it might be usable. PICs are mostly programmed in C or assembly language. There are lots of C tutorials on the web, and books, but you need to focus on embedded C...
  5. KrisBlueNZ

    help over microcontroller code

    Good analysis kpatz! It's not usual to send the 0x0A at all; just the 0x0D is normally used on command strings. If the device has local echo enabled, it will echo a 0x0A along with the 0x0D, but modems do not normally expect to receive a 0x0A character. Also it's normal to have a separate...
  6. KrisBlueNZ

    Power adapter question (newbie)

    Hello and welcome to Electronics Point :) That adapter looks suitable for your requirements. At USD 3.99 it is unlikely to be very good quality; this may result in shortened lifetime (i.e. it may go pop or start a fire) and possibly problems with noise, but according to its specifications it...
  7. KrisBlueNZ

    Need help with I hope simple project!

    Yeah... I was going to suggest adding a bit of shiny metal in front of the headlight as a reflector, but I thought "that's too obvious..."
  8. KrisBlueNZ

    Designing a Time Delayed Relay

    Yes, that's right. You haven't deleted the other components that were in parallel with the old LED position yet though. Yes, it's the standard T1 3/4 package, 5 mm diameter. I thought you might choose one of the 3.7 mcd green ones. This one has a diffused lens which gives it a wide viewing...
  9. KrisBlueNZ

    Why did the designer put a 350v cap when the max voltage of circuit is 20v?

    I can't suggest a reason. But I notice that the capacitance and voltage markings for C4 are in a different font from all the other markings on the diagram. Maybe it wasn't originally designed with a 330V capacitor. Maybe someone has made a mistake.
  10. KrisBlueNZ

    Help with photoflash capacitor charging circuit

    The size doesn't matter. That circuit should work regardless. There are much better ways to drive it though. This page looks good. The second circuit (the "Mk II" version) is best. He is talking about driving flyback transformers from TV sets but your transformer uses the same idea. Connect...
  11. KrisBlueNZ

    Help with photoflash capacitor charging circuit

    Looks exactly the same to me. What's the difference? Those circuits run at low voltage and use a transformer with a tapped secondary. Which transformer is much bigger?
  12. KrisBlueNZ

    Help with photoflash capacitor charging circuit

    It's amazing what a quick Google image search will get you... http://www.lunar.org/docs/LUNARclips/v5/v5n2/Lights.html#Modifying Disposable Cameras http://www.intrepidcreativity.com/reverse/dc/dcschem.gif
  13. KrisBlueNZ

    Designing a Time Delayed Relay

    A 2.2 µF 10% capacitor will be suitable as C1 with the increased load due to the second Allegro chip. Here are three options available from Digikey: P15514-ND: 2.2 µF ±10% 275VAC Panasonic ECQ-UAAF225K USD 1.58 stock=675 http://www.digikey.com/product-detail/en/ECQ-UAAF225K/P15514-ND/3182273...
  14. KrisBlueNZ

    Designing a Time Delayed Relay

    When the device is being programmed in-circuit, the programmer supplies voltage onto the VDD rail, and uses pins 6 and 7 to communicate with the device. R5 is 33k and this is so high that it will have almost no effect on the signals being communicated over those pins. All that will happen is...
  15. KrisBlueNZ

    Why put MOSFET's on negative side vs positive of motor

    Here's the image from post #1. It doesn't show up in the thread here, but it came through in the notification email that I received for the thread. The simple answer is that the MOSFET responds to the voltage between its gate and its source. Connecting the source to the 0V rail means that the...
  16. KrisBlueNZ

    Designing a Time Delayed Relay

    Pin 5 is used as a mains-frequency signal input for timing. Without it, timing accuracy is determined by the accuracy of the on-chip clock oscillator, which is typically a few percent, worst case ±5%. That's why I suggested using pin 2 of the micro for the signal from the second Allegro chip...
  17. KrisBlueNZ

    Questions from a new guy

    Hello and welcome to Electronics Point :-) Yes, pots are available with switches built in. http://www.digikey.com/product-search/en?pv1=1110&pv1=611&pv23=26&FV=fff40004%2Cfff80335&stock=1&quantity=1
  18. KrisBlueNZ

    SMPSU failures

    I don't know. Normally when SMPSes die, it's because of a power surge, or dry joints, or perhaps optocoupler failure, not because the output has been shorted out. It's not hard to measure the output rectifiers, so I'd start with that. Also check the input fuse; if it's blown, it's likely that...
  19. KrisBlueNZ

    Led flikers?

    You're welcome :-)
  20. KrisBlueNZ

    AVR ASCII Video Terminal

    Here's a link to the Google translated version of that article: https://translate.google.com/translate?sl=de&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.mikrocontroller.net%2Ftopic%2F53140&edit-text=&act=url The firmware supports "96 ASCII characters" but the description doesn't...
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