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  1. C

    Serial help?

    I wonder if someone can point me to a basic tutorial on serial transmission - I've been working on a project for a while, and some background would help me work out some of the problems I'm having. I'm using inverted signals, while tying pins to +5v with a 1K resistor. I set the pins to high...
  2. C

    Serial between uCs...

    I'm sending serial signals between several different types of microcontrollers. For some reason, my Picaxes can only understand each other, and nothing else understands the Picaxes. My BS2s have no problem talking to my BX-24s. I'm trying to use 2400 baud, 8 data bits, no parity, one stop bit...
  3. C

    8M comm

    I've been messing with serial communication for a while now...I have to have 2 outputs share an input line, making diode mixing necessary. I have some 1N914 diodes, and I was trying to find out how to orient them, and they seem to pass a logic signal regardless of which way I put it in the...
  4. C

    8M serial communications

    I've been getting spurious results with a project I'm working on using multiple Picaxe 08M's communicating serially. I need to be able to connect & remove lines while the circuit is running, and the 8M's seem to have a hard time linking up right - sometimes the bytes are in the wrong order, and...
  5. C

    08M reset?

    I'm working on a project with two 8M's connected to another uC. I've found that the 8M's are getting powered up through the serial line, which is a problem because I can't reset them now, and they spend all their time hanging on a serin statement. 1. Is there a direct way to reset an 8M...
  6. C

    Serial issue

    I've got a 08M hooked up to another uC...if I press a button, the 8M sends a short string with the serout command. When just the grounds are connected, a logic probe shows the signal on the pin, but when I connect the pin to the input on the other uC, the stream isn't there anymore. What gives...
  7. C

    Picaxe manual wiring diagram

    Can I safely assume a "4k7", referred to often in the manual, is a 47k resistor?
  8. C

    Using DATA with words?

    How do I store word variables in DATA, and get them back again in the same condition? I keep having some kind of "transporter" problem, like in that Star Trek movie...
  9. C

    Math help - sine wave servo positioning

    I have to move a servo with fluid motion, approximating a sine wave. I want it to move back & forth between its limits, with the fastest motion in the midpoint, and slowest near the ends. The limits will themselves change, but I can probably figure that out myself if someone can give me the...
  10. C

    Prototype board

    I put a socket for a 24vdc wall adaptor on my prototype board, with a 7805 5vdc regulator and 47uF capacitor between ground and output (5v). The center pin is ground, both on the adaptor & the plug. 24v only goes to the Input leg of the 7805, and nothing else. This simply sends 5v to the...
  11. C

    Ignition system

    I have an old 1-cylinder 2-cycle engine that has bad points. I can't get new ones, and I really don't want to pull the flywheel off of it. I was wondering about the possibility of making an ignition system, with either a Hall effect sensor, or perhaps an optical sensor. Would a Picaxe be fast...
  12. C

    Bidirectional pins on the 14M?

    Can someone shed some light on selecting pins as input & output, for bitbanging?
  13. C

    Where is the 14?

    I need a few more pins, so it looks like I'll be upgrading to the Picaxe 14, or 14M. I can't seem to find it anywhere, including here, though I do see references to it in the forum. What happened to the 14?
  14. C

    Controlling 3 transistors with 2 pins

    I have to rig up some sort of logic gate, cheaply. I have 3 lights, only one of which will be turned on at any time. I only have 2 output pins free. I'd like to use a couple of transistors as a makeshift logic gate, as they're cheap, but I'm having a little trouble figuring the wiring out. Can...
  15. C

    8M speed encoder

    I building an encoder using a photocell and illumination LED with a black/white disk on one of the gears. Has anyone here any similar experience? I'm concerned about data loss due to rctime lag. What is the maximum RPM I can expect to measure with an 8M?
  16. C

    Computer interfacing?

    I'd like to write some applications involving more computer & user work than Picaxe work. I'm comfortable using Pascal, and I'm familiarizing myself with Free Turbo Pascal, and I'd like to know how I would go about giving commands to the Picaxe remotely...does anyone have any experience with...
  17. C

    US source for Picaxe 08M?

    Is there someone in the US I can get some Picaxe 08M's from? My company needs some, and the only US source I've found refuses to provide invoices, is rude & ignores emails. UPDATE: I have now been banned from bidding on this company's products, because I had the nerve to ask for a...
  18. C

    pin 0 functionality?

    I have to use pin 0 as a clock line, but I'm having some problems, and I think it's a result of trying to use pin 0 as a clock line. :) The program seems to work fine on the prototype board, but when I switch pins for the application, nothing seems to work...is there something I have to do to...
  19. C

    Tying leg 2 to ground?

    Well, my Picaxe-08M to SHT-11 program is working, but it does nothing when installed in the (already-checked) hardware. I see I can't keep leg 2 floating, and must tie it to ground for it to work. The manual says a 22K & a 10K resistor, but the chip won't be programmed in the circuit - can I...
  20. C

    SHT-11 with Picaxe-08M

    I'm still working on it...I'm studying the SHT-11 docs & the BS2 code, which works, and now I can't figure out why. According to the doc, the SHT-11 defaults to a 12-bit measurement, and the BS2 code appears to assume 8-bit readings. I still haven't been able to get the Picaxe to get a...
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