Recent content by hippy

  1. hippy

    Can I control the brightness of 2 or more LED's with PWM?

    The main problem I would guess is there is no PAUSE command before your GOTO MAIN at the end. This means the program runs incredibly fast, possibly too fast for the PWMOUT hardware to keep up with, so you are seeing odd LCD flickering. You are also setting your PWMOUT frequencies differently...
  2. hippy

    Picaxe Timing Accuracy

    An RTC doesn't have the current local time programmed into it when delivered but it can have its time programmed. That can either be done with a program download and by providing some other means for the time to be set; LCD plus buttons, GPS input, etc.
  3. hippy

    Picaxe Timing Accuracy

    I couldn't even find a 26C16 datasheet via Google, but if it is a good old fashioned parallel EPROM I would suggest you would be better off using an I2C EEPROM, particularly an RTC+EEPROM module as suggested earlier. You won't need 11 address lines and 8 data lines, whatever RD and WR lines are...
  4. hippy

    Picaxe Timing Accuracy

    Never used the DS3221 or alarm functions but I'll have a read of the datasheet and see what I would would best guess at. Others are more than welcome to chime in they have an answer.
  5. hippy

    Picaxe Timing Accuracy

    It's not clear why you would be storing data at address 0 through 11, why there's so much data. Or why there's any need to store any date or time info per sample. Each sample will be six hours after the last so just the starting date and time would need to be stored. If you are sampling four...
  6. hippy

    ADC INPUT - DAC OUTPUT how can I smooth out the 32 steps.

    That could be a problem. The way multi-tasking works is it executes one command from one task, then executes one from another. That means how quickly any task is running, or how frequently a particular command is reached, depends on what is being done in other tasks. An alternative is to use...
  7. hippy

    ADC INPUT - DAC OUTPUT how can I smooth out the 32 steps.

    You could potentially 'dither' the outputs with an appropriate RC filter; continually switch between two levels to achieve a third. For example 4 and 5 should give 4.5, 5 and 6 should give 5.5. That will increase 32 levels to 63 levels.
  8. hippy

    Picaxe Timing Accuracy

    A year is 365*24 hours = 8760 3 hours is (3*100)/8760 = +/-0.034% A PICAXE has an internal oscillator with +/-2% accuracy. I have never known it to be too far out from what's expected but that's looking at microsecond timings and only intantaneosly, not long term. An external oscillator would...
  9. hippy

    Understanding max min

    MIN means ensure greater than a minimum. 4 is bigger than the minimum 0 so it remains as 4. When you subtract 'b0', if that's greater than 4 the result would go negative, but negatives are large positive numbers, eg 5-4 = -1, -1 is $FFFF (65535). When that is truncated to an 8-bit byte it...
  10. hippy

    sim900

    It is more common to connect hSerOut to an RXD pin, because that's how it is from the device's perspective, but sometimes a pin can be labelled TXD to indicate what it connects from. And, yes, it can be confusing! Almost. Normally "AT<CR>" is send out, "OK<CR><LF>" is echoed back. In this case...
  11. hippy

    sim900

    HSEROUT sends the "AT", everything received is automatically handled by the background receive code by the PICAXE firmware, specified by the %001 in the HSERSETUP command.
  12. hippy

    sim900

    That would seem to be correct. I would double check the wiring. Especially that the wires are not crossed over. You shouldn't receive anything if the phone is not connected though electrical interference and pick-up might generate some meaningless data. The Scratchpad only collects what's...
  13. hippy

    sim900

    Start with something a little simpler - #PICAXE 28X2 #Terminal 9600 hSerSetup B2400_8,%001 pause 2000 SerTxd ("Started.....",cr,lf) MAIN: do hSerOut 0, ( "AT",cr ) pause 2000 do while ptr <> hSerPtr b0 = @ptrInc SerTxd ( "Rx", tab, #b0, tab...
  14. hippy

    sim900

    Post the full code you are using and we can check if it looks like it should work, and what you should be seeing.
  15. hippy

    14 m chip coding

    The 14M has fixed inputs and outputs, the 14M2 allows more flexible configuration of which pins are used for input or output. So long as you put your inputs on the left of the chip (C.x pins) and have your outputs from the right of the chip (B.x pins) the wiring and code should be the same for...
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