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  1. H

    FVR 1.024 positive reference question

    It's a 28x2. I think I'll end up using a resistor divider across the 5v power supply. If I have a resistor divider with 3 resistors: 1.8k,1k,1.8k, then I can connect the high part of the 1k resistor to ref+, low side to ref-, and have full 10 bit positive and negative current range within that...
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    FVR 1.024 positive reference question

    Oh, I just realised that I think I can't use FVR1024 as the positive reference because the analog voltage measured will be higher than 2.5v..... Initially, I thought the command added 1.024V from the negative reference. I might still use the 2.5V sensor wire as the negative reference and use...
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    FVR 1.024 positive reference question

    Hi all, The online manual for the FVR command says "Note that the 1.024V reference may not be accurate if used as the Vref+ of the ADC (only 2.048 or 4.096 should be used for this purpose). " Can anyone elaborate on...
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    Receiving Hisense TV IR signals. Is this possible?

    Thanks so much IWP! Your code is a fantastic running start. My aim is to get the Hisense remote to control the amp volume. I don't want to keep switching from 1 remote to the other. The amp has an encoder type volume control so I'm hoping to solder wires to the knob and spoof high/low...
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    Receiving Hisense TV IR signals. Is this possible?

    Hi all, Is there a way for any type of picaxe to receive Hisense volume IR commands? I know the irin command receives "Sony" commands but is there maybe a tricky way to get other brands of remote control to work? I only need to receive two buttons from a Hisense TV remote. Volume up and...
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    external resonator on 28x2 chip

    Sorry guys, I must be going crazy. I thought I bought a 64Mhz resonator, but I was about to post the link to the datasheet of the part i bought, and I realised that I bought the 16Mhz resonator, so all this time, when I was shopping for the resonator, I must have subliminally known that I needed...
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    external resonator on 28x2 chip

    I am sending Sertxd ("hello") after the setfreq em64 command and both the editor and a third party serial program are picking up the ASCII string at the higher baud rate. I'll confirm what that baud rate is tomorrow. From memory it's 76800 baud.
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    external resonator on 28x2 chip

    Just tried serial communications, and that all works fine too.... really strange that it works !
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    external resonator on 28x2 chip

    Hi all, I purchased a 64Mhz resonator, and installed it on my 28x2 picaxe. I used setfreq em64 command in the editor. It accepted a download and it works. But then I remembered that the chips have a 4x PLL phase lock loop and I SHOULD have installed a 16Mhz resonator instead. From the manual...
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    Serial graphing program

    Just to answer my own question, I tried the aptly named SerialPlot program, and it just works great!
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    Serial graphing program

    Hi all, I have 8 ADC channels sending a serial string out to the PC. It all works well through the terminal program. Has anyone heard of or found a (free) program that can plot the 8 values on a moving real time graph?
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    12c communications

    Hi all, I'm working on having two picaxe chips (20x2) communicate with i2c. Things are going well but I have a problem. The master runs this demo code (the final product will have 8 different variables that will change depending on some other sensors): b1=1 b2=2 b3=3 b4=4 init: hi2csetup...
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    i2c pullups

    Hi all, I want to use a 5V picaxe with a 3.3v i2c device. If I set the pullup i2c resistors to 3.3v instead of 5v I believe it should work. But I just wanted to make sure that the Picaxe works correctly in that it "pulls down" the line to communicate (as required by the standard), and never...
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    Can't download new program after setting setfreq M64

    Hi all, I have a program that is working fine in my Picaxe 20x2 but I can't update the program any more. The picaxe won't take a new download. After the setfreq M64 command, I immediately have a serrxd command. I think what is happening is that the processor is working so fast that it gets to...
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    ADC external comp pins

    Hi all, I want to use the comparator pins on a 40x2 chip for reading adc10 voltages using an external precision voltage source for best accuracy. The manual says the adcconfig Vref+ pin is A.3 and the Vref- pin is A.2, but in the picaxe pinouts section here...
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    HX711 load cell connecting to Picaxe

    Hi all, I've ordered a HX711 load cell ADC for a strain gauge I wish to measure. I believe I have to use the hspiin and hspiout commands or maybe the shiftin shiftout commands, but am not quite sure where to start. Has anyone used this chip before and could you share your code? From the manual...
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    1.5v voltage drop when powering 20ma load

    Hi all, I am running a 20ma laser diode directly from pin c.7 of a Picaxe 20x2. I have measured the current at 18ma. It works but there is a 1.5V drop at the pin while powering the laser. So the output is 3.5V instead of the expected 5V. The input to the picaxe is a stable 5V. Is this...
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    vref FVR and ADC10

    Hi all, Quick question: If while using a readadc10 command, I set the FVR to 1.024 Volts, and my input on the ADC pin happens to go over 1.024 volts (but less than VCC) I won't damage the picaxe right? It will just saturate the internal op-amp right? Just making sure!
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    simple volume control using floating pins

    Hi all, I am thinking of ways to implement digital volume control on a microphone amplifier in the simplest way possible. I am thinking of using say 4 or 5 picaxe pins, and connecting them DIRECTLY to the DC biased low line level audio signal through various resistor values. The program...
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    strange debug behaviour on 18M2

    I have been trying to chase down an issue in my programming. Not sure if I have found the bug yet but during my testing, I found something strange going on with the DEBUG command. To see if my hardware is OK, I wrote a short program below.... as you can see, it polls the state of four inputs...