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    Slot and Run commands with external EEPROM

    This is a theoretical question. I know that there are 4 program slots on a 28x2. Slot 0 is the default. I also know that you can store additional programs on a memory chip (24LC512, lets say) and then run them using the i2c bus. The problem is that when you do this, the i2c bus is "locked...
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    ADC pin protection from overvoltage

    Hi All, I'm building a circuit that needs to be able to detect whether the incoming voltage is 12-14v or 24-28v DC. The detection is the easy part. Use a voltage divider and send the result to an ADC pin. Easy. The part I'm concerned about is overvoltage. If for some reason more than about...
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    PWM Motor Control, MOSFET getting VERY hot?

    PWM Motor Control, MOSFET getting VERY hot? - SOLVED!!! Hi all, it's been a while since I've posted, but I hope someone can shed a little light on my latest project. This is a simple project using a 20X2's PWM function on C.5 to manage the speed of a fairly high powered blower motor. The motor...
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    graduating from the picaxe

    I will most likely never stop using picaxes for various projects, but being what they are, they have many limitations, so I am looking to graduate from the picaxce to a more powerfull microcontroller. I would be interested in hearing recommendations on what people think the next step should...
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    decoupling capacitors

    okay, I need to know, how critical are decoupling capacitors in a well-rounded circuit that uses relays, temp sensors, serial transmissions, and i2c bus and a buck/boost power suppy. What recommendations do you have as to size, type and placement? seems like every place I turn to has a...
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    Odd properties of Readtemp on other pins

    Okay, I may have missed the documentation on this odd little quirk, tell me if It's documented somewhere: If I use the readtemp command on c.7 on a 20X2 while having b.1 and b.2 held high, the readtemp command causes b.2 to go low during the command. Afterward, b.2 goes high again. I tried...
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    Running code from a 24LC512

    Hello all, I have seriously run out of space on one of my 20x2's. I've done everything I can to make sure I have squeezed every last bit out of it! So my next questions is this: is it possible to run code from another chip? for example, if we have one chip talkting to a 24LC512 via the i2c...
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    2 picaxes and one memory chip

    Hi all, is it possible to have two picaxes reading and writing to a single i2c memory chip? I am working on a project that needs to be able to do just this. I am using two 20x2's and a single 24LC512. wiring them up isn't a problem, but I'm not sure how the i2c timing would work. having a...
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    Using a BCD Switch to "tune" up and down

    Hi all, I did a quick search and didn't find anything so I thought I'd post. I'd like to use a 16 position BCD swith to "tune" a radio I'm working on. simply put, at the switch is turned clockwise, the radio tunes UP in frequency, as the switch is turned counter clockwise, it tunes DOWN. Is...
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    Prevent EEPROM from clearing

    Do you guys know of a way to prevent the memory in the Picaxe, once loaded with variables using the EEPROM command, to retain the data instead of resetting all the values to zero? I'd like to be able to store some data in these locations instead of using an external memory chip like the...
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    Multiple slots on the X2 - what am I doing wrong?

    I don't think I'm doing anything too difficult here, but the picaxe editor won't seemto let me do it... so where's my goof up? I'm trying to load 2 programs into 2 slots... here's what I'm doing: PROGRAM 1: #slot 0 #no_data ... program code... if pinC.6 = 1 then run 1 endif With this code...
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    combining variables

    Working with a DS1307 Is there a way to combine variables like this: b1 = 1 b2 = 2 b3 = (b1 + b2) = "12" b3 = 12 Is there a way to do this? I don't want to add them together, I just want put combine them...
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    GREAT applet for experimenting with circuits

    I don't know if anyone else has found this little gem, but it's worth posting on here. CIRCUIT SIMULATOR APPLET Really neat, and accurate!
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    witching a mosfet with ground

    Can anyone point me in the right direction as to how to switch a logic level mosfet with a ground? I can't supply +5 to the gate directly, the chip I'm using to switch it only switches the ground. I'm thinking I needing to use an NPN transistor, but I'm not sure I'm on the right path...
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    i2c LED Driver driving me nuts!

    Hi all, I'm experimenting with a Texas Instruments TLC59116FIPWR 16 Channel LED Driver chip that is controllable via i2c. I can get the registers to config and using the code below I can read them back no problem. They all take just fine, but I can't get a single LED to light (using output7)...
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    Custom Heatsinks

    Anyone know of a company that will do small run (4 or so) extruded heatsinks in a custom profile? These heatsinks have to be 48" long
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    Free Samples of Electronics parts

    Hi all, does anyone else have experiences getting free samples? I konw there are several places on the 'net that have running lists of places that you can get free samples of semiconductors and stuff. thought I would share my results getting some free samples. Luckily, I have a legitimate...
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    Stupid math question

    Okay, here's whats going on - and I am sure the answer is simple and will make me slap my forehead...LOL. Working with a Maxim DS1721 Temp chip and I am getting good readings from it via i2c, that part works fine. What I don't get, it how to take the data and turn it into meaningful numbers so...
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    VFD Brightness

    I'm using a Samsung 20T202DA1E VFD with a project (okay, several projects) and have run into a problem trying to set the brightness. The datasheet is HERE on the datasheet, the function set to change the brightness is on page 12. I'm using an LCD117 chip bought from phanderson.com, it's a...
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    DS1307 Locking Up

    Set my DS1307 RTC circuit up yesterday and left it running all night, came in this morning to find the LED connected to SQWOUT solid and the display was about an hour off. Background This circuit is just running on a breadboard right now, it's as simple as it gets: 20x2 Picaxe DS1307 2 4.7K...
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