Mark Williams
  • Member for 7 years, 1 month
  • Last seen more than 1 year ago
what is the use of "<<=" operator?
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4 votes

As stated in the other answers, the <<= operator shifts the byte to the left; however, the number '1' after it specifies how far to shift it - so, 2 <<= 2 == 8. Possibly clearer in binary:...

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Why are LED 0 and 1 on as well?
4 votes

You haven't initialised the other pins at all; or included your circuit, but clearly you have LEDs on more pins than those defined (5 defined, 7 on). The other LEDs are, therefore, in an undefined ...

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Is there a thermal sensor with a distance of 10 meters for Arduino
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3 votes

How about this one at £20? The range depends on what lens you put in front of it - this has to be plastic as IR doesn't penetrate glass, but you can set your own range, like a focus adjustment. ...

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Hall effect sensor direction detection using arduino
2 votes

According to the data sheet (see below) the no-field PWM output is mid-range; north poles reduce it & south increase. So if you had an arrangement whereby the float had north down & south ...

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Can I have help interperting this code? char variable somehow storing big numbers
2 votes

Keeping it simple: char *number; a variable pointing to a character (or string of them). char sendbuff[35]; 35 characters in a row, making a string. The first 3 chars at locatiion sendbuff are ...

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Powering LCD Displays without a Breadboard
2 votes

I presume you're looking at this page - the breadboard is merely a convenience, you can just hard-wire the LCD directly - most don't even come with that header plug soldered on.

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How to delay so that LED stays on a bit longer?
2 votes

Insert a delay of 500ms? function cycle() { for ( var i = 0; i < bytes.length; i++ ) { console.log(bytes[i]); sr.send(bits[i]); delay(500); } }

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GPS North? South? East? West?
1 votes

GPS is a positioning system: it doesn't do direction. If your software has serial information coming in, it can take the difference in readings and generate that data but GPS doesn't do it for you. ...

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LEDs instruction code does not loop
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1 votes

Your 1st pixel should go indigo & stay there, & the other 2 very briefly show Aqua before going back to Indigo. Try a longer delay than 0 at the end, and then clear them down for the next loop....

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How to read pH value
1 votes

This is SOME of the code. We are missing the avergearray() function.. I suspect you're taking one reading and averaging it with both old & future ones, but this code clearly is meant to sit in a ...

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Hall Effect Sensor for POV Project
1 votes

From the datasheet of the hall effect sensor, the thing is only checking for 125usec in every 125msec - so if your magnet whizzes by in <100msec it will miss it. Obviously you haven't stated the ...

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Do I need the Motor Shield to drive servo motors?
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1 votes

The shield will drive a pair of DC motors (the common small ones in models), or one stepper motor (the precision motors you find in dead printers, etc), and can also connect onwards to other stuff, ...

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How can i use a TFT Screen shield along with other sensors and transmitters
1 votes

You need another layer! A breadboard shield - from the same source if you like - would seem the obvious answer. Alternatively, take flying leads from the pins you are using to the screen & mount ...

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Question about infrared receiver with metal shell to detect heart pulse rate?
1 votes

"Proper" oxygen meters use a bimodal LED - red + IR - so there will be limitations to this. They also have a piece of copper foil wrapped around the sensor & heavily earthed, so your shielded ...

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Powering Arduino Uno R3 with battery packs
1 votes

The battery will be fine; the 1A rating is just a maximum, if your device only wants up to 500mA then it's got spare capacity, is all. The battery appears to have in-built short protection etc, so ...

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Arduino board not recognized by Linux (dmesg, lsusb, etc.)
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1 votes

So, to summarise the comments trail; the blinking lights at power-up are the normal boot sequence for the Leonardo, indicating the processor is good, and that power is reaching the board; the device ...

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Freeze with VCNL 4000 Proximity Sensor
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1 votes

You really can't expect this to work unsoldered. The contacts will be at best intermittent, and poor contact. Even a 'dry joint' where the pin is mostly surrounded by solder doesn't work well, these ...

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Possible arduino burned (5V shorted to Vin), explanations and suggestions
1 votes

If you have another Uno then your best bet is either: 1) Swap the suspect processor into the known good board, test it. 2) to buy a replacement chip (ATMega 328-PU), use this link to flash it, if ...

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Variable current switch by human touch
1 votes

Okay; to start with, the Arduino Playground has a how-to guide, the components are commonplace - either recycle a high-resistance resistor from junk or buy one from eg Maplin at 38p. This works as ...

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Homemade soil moisture analog value reading jumping from 0 to max
1 votes

You are constantly running .5mA through 2 nails in wet earth. What are they made of, that won't undergo some electrolysis in 1/2 hour? Gerben appears to have hit the, er, nail on the head in one, ...

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Discrete H-Bridge very low current output
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1 votes

Design 1 wouldn't be my first thought on how to do this either! The transistors aren't a great choice, but are cheap & common. The layout here is more conventional, and you can physically link 1-...

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AVR ATmega328p-pu operating circuit?
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1 votes

You're looking for this I think? How to set up an Arduino on a breadboard.

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How to detect high/low signal from a DC servo motor using arduino?
1 votes

Do you need to check if it is stalled? Or simply running? Either way, you could check the voltage with an analogue input, compare against a threshold (empirically set) & use that. Take the ...

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Bipolar LEDs flicker when sensors are polled
1 votes

You have your LED's across one of the serial I/O lines (Pin 1). Use different pins.

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Assigning values to char array causes program to not run
1 votes

The 'dark magic' is going to be your program rebooting every time it gets to that line. I would imagine (this isn't a library I know) that you're exceeding an array bound & generating a 'segfault',...

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Using A 4 Ohm Speaker With Arduino
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0 votes

5v, 4ohm, >1amp from a pin rated for 0.04amps; this isn't safe! You would need a driver, but it would suffice to add a small transistor & a couple of resistors to drive it; here is a slightly more ...

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Is there any way that the values here be converted to another variable and not string?
0 votes

The UidByte[] is a 10 character array, loaded with the tag ID (this is an RFID reader) by the library. Your code is attempting to put a character value into integer variables. What you mean to do (I ...

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Programming an Array of ATTiny
-1 votes

Well you need access to pins 0 & 1 to program them, so you either do it off-board, or design in a way to access them - perhaps a PCB hole you can wire to temporarily, or a link you can fit/remove ...

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