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6001  Using Arduino / Motors, Mechanics, and Power / Re: Arduino Motor Shield output Voltage problem on: February 22, 2012, 05:23:46 pm
Set the PWM output to 255.  Then the output voltage should switch between + the supply voltage to - the supply voltage as you change direction.  If one of the voltages is still WAY off there is probably a problem in the H-bridge.
6002  Using Arduino / Motors, Mechanics, and Power / Re: 2MOTOR for Arduino Nano Installation Help on: February 22, 2012, 11:16:48 am
Are heat sinks necessary with this design? I'm under the impression that they aren't needed and the arduino will realize when it is too hot.

Also how would I get the motors to react based off the values I receive from a digital distance sensor?
You just have to keep the Arduino out of very hot environments.  Somewhere it should say what the limits are but temperatures that are comfortable for people are usually well within the limits that a microprocessor can stand.  The motor controller may benefit from a heatsink if it is driving a motor close to its power limit.

You can control the motor by setting direction and speed as shown above. You write a sketch to read from the distance sensor, calculate direction and speed values from that input, and control the motor.
6003  Using Arduino / General Electronics / Re: Help choosing a relay for a thermostat on: February 17, 2012, 10:34:14 am
Looking at the info from my boiler it says the thermostat must be able to switch mains voltage and looking at the diagram it switches the live power to all the circuitry. does not mention current draw though

In the USA we use a box called a Safety Relay.  There is a low-voltage loop that goes to the thermostat.   For an oil heater it has a flame sensor that checks that the furnace has lit so it can shut down the pump/blower if the ignition fails... don't want to fill the firebox with oil!  For a boiler there is also a connection to a pressure switch so the burner can be turned off when the steam gets up to proper working pressure.

Gas-powered furnaces often use a thermocouple pilot-light sensor to enable the gas valve.  In some cases the thermostat is just put in the millivolt circuit.  The gas valve is opened if the pilot light is lit and the thermostat closes the circuit from the thermocouple to the gas valve.

Is your boiler electric? Oil? Gas? Something else?  What regulates the steam pressure?
6004  Using Arduino / Motors, Mechanics, and Power / Re: Arduino Motor Shield can't fit on Arduino? on: February 17, 2012, 10:18:31 am
That wouldn't fit a uno either.

Just because it has some extra pins for which the UNO doesn't have sockets doesn't mean that it "wouldn't fit".  Just ignore the extra pins.
6005  Using Arduino / Motors, Mechanics, and Power / Re: 2MOTOR for Arduino Nano Installation Help on: February 17, 2012, 03:51:18 am
For a 3V motor, connect 3V to the motor power inputs marked "7-12V".  Hook motor to A1 and A2.
    digitalWrite(4, direction);  // LOW for one way, HIGH for the other
    analogWrite(5, speed);     //  0 for OFF to 255 for full speed.

IF your motor runs on 7 to 12 volts you can close the "VIN" jumper (near the RST pin of the Mini socket) and you can run the Arduino off the same power supply as your motor.

IF your motor uses less than 7 or more than 12 volts you have to cut the "VIN" jumper and provide a separate power supply for the Arduino since the regulator on the Arduino board needs at least 7V and gets too hot if used with more then 12V. You can use motors up to 24V
6006  Development / Other Software Development / Re: working with LiquidCrystal on: February 17, 2012, 03:20:26 am
Does your sketch start with this:

#include <LiquidCrystal>
6007  Using Arduino / Installation & Troubleshooting / Re: Time library works with Arduino0022, but not with Arduino1 - bug? on: February 17, 2012, 03:18:14 am
It apparently failed to find Time.h so of course the Time library functions are not defined.

Is Time.h in the folder "{sketch folder}/libraries/Time"?  If not, that could explain why Arduino 1.0 couldn't find it.
6008  Using Arduino / Project Guidance / Re: Need help on a project. on: February 17, 2012, 03:10:45 am
The glasses you show seem to be a (sparse) matrix of 8 rows and 24 columns.  The hard part will be keeping the row wires from shorting against the column wires.  The glasses shown seem to be laser-cut PCB with the horizontal traces etched and solder-masked.  The surface-mount LED's have one end soldered to the PCB and the other end connected with very fine wire.
6009  Using Arduino / Networking, Protocols, and Devices / Re: Problem in CODE for WiShield v1.0 on: February 17, 2012, 02:54:40 am
I think Arduino 1.0 finds the libraries to build by matching .h filenames to library folders.  I suspect the library folder is called "WiShield" and not "WiServer".  Perhaps if you added a "#include <WiShield.h>" before the "#include <WiServer.h>" it would build and link the full library.
6010  Using Arduino / Installation & Troubleshooting / Re: Arduino Bootloader on a 328 w/Mega2560 on: February 17, 2012, 02:49:15 am
I tried ArduinoISP under Arduino 1.0 and, like many others, I had no luck getting it to work.  At least one person ( found that increasing the Serial buffer from 64 bytes to 128 bytes fixed it.  Another in the same thread mentioned that lowering the baud rate to 9600 worked as well.  It seems that the lack of flow control combined with a high baud rate and small Serial buffer cause a buffer overflow (characters get lost).
6011  Using Arduino / Interfacing w/ Software on the Computer / Re: Does G-Code require interpreter to respond after command? on: February 16, 2012, 08:29:48 pm
The software that sends G-Code might implement a flow control protocol (like XON/XOFF) or it may assume the underlying serial hardware will do it with hardware flow control: RTS/CTS signals.
6012  Using Arduino / Microcontrollers / Re: Fuse Q. Which Crystal option? on: February 16, 2012, 08:21:44 pm
hmmmm... Using this fuse calculator with the atmega 328p selected, I do not seem to get that option.

If I have time tonight, I'll read through the data sheet to see whats going on.

Apparently "Low Power Crystal Oscillator" is so standard they just call it "Ext. Crystal Osc.".  You can tell because of the CKSEL ranges in the datasheet:

Low Frequency Crystal Oscillator = 0100 through 0101
Full Swing Crystal Oscillator =  0110 through 0111
Low Power Crystal Oscillator = 1000 through 1111

6013  Using Arduino / General Electronics / Re: Hlep choosing a relay for a thermostat on: February 16, 2012, 05:48:09 pm
Your Arduino works on 5V so to use that relay you would need both a 12v power supply and a transistor to switch the 12v.

You would be better served with a relay with a 5v coil that draws 30 mA or less.  That way you can drive it directly off the Arduino pin.
6014  Using Arduino / Installation & Troubleshooting / Re: File size limit on miniSD card? on: February 16, 2012, 05:34:01 pm
The FAT16 file system can handle files up to 2GB.  i suspect your email server is the one with the size limitation.
6015  Using Arduino / Interfacing w/ Software on the Computer / Re: Does G-Code require interpreter to respond after command? on: February 16, 2012, 05:27:00 pm
When G-Code was first developed the characters were punched into paper tape.  The CNC machine would read characters from the paper tape until it had something to do and then to that.  When it was done with the operation it would read more from the tape.  This is a from of "flow control".  The Arduino doesn't implement any flow control on the serial port so if you want it you have to implement it yourself.  One way to do that is to use XON and XOFF characters.  The Arduino would send XOFF to the PC when it had enough data to work with and send XON when it was ready for more.  This would require a program on the PC side that could handle the XON and XOFF characters arriving from the Arduino.
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