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31  Using Arduino / Project Guidance / Re: Schematic to perfboard, need some advices on: July 15, 2014, 09:45:33 pm
D1 is upside-down.
You don't want to forward-bias that diode in normal operation.

Everytime I see "nF', nanofarad, I think of hectograms and dekalitres (or hecto- or deka- anything)
32  Using Arduino / General Electronics / Re: ATMega328 and LM2575 switching voltage regulator noise issue on: July 15, 2014, 09:37:59 pm
AVcc to Vcc (+5)
But Aref just gets the cap to Gnd.

AVcc vs Aref (I've done that, too.)
33  Using Arduino / Motors, Mechanics, and Power / Re: PWM dc motor on lowest duty cycle on: July 15, 2014, 09:04:02 pm
If the PWM is restricted to low duty range  (short motor on-time) then a higher motor voltage may be acceptable.

34  Using Arduino / General Electronics / Re: Are residential customers billed for Real or Apparent Power ? on: July 15, 2014, 08:46:46 pm
https://www.progress-energy.com/assets/www/docs/business/power-factor-how-effects-bill.pdf

More heat than light?    P-:

https://www.keysenergy.com/doc-download/PowerFactorFAQ.pdf

http://cooper-electric.net/industrial/power-factor-corrections/

Find more. I googled
power factor and commercial electrical billing
35  Using Arduino / General Electronics / Re: Are residential customers billed for Real or Apparent Power ? on: July 15, 2014, 08:06:12 pm
Thanks everyone. It's settled then, power utilities measure real power ...

Not so fast.  The utilities make certain assumptions regarding inductance.  Big companies, commercial users, have "capacitor huts" and such to compensate, to bring the PF right.
It may be that the "smart meters" will end the assumptions they calculated for till now.
36  Using Arduino / Programming Questions / Re: Gesture Control Car Using MPU6050+nRF24l01 (Help me, quickly!) on: July 14, 2014, 07:25:04 pm
there is nothing show in the serial monitor in transmitter side

There are no instructions there to do so.
37  Using Arduino / General Electronics / Re: Using a 4N35 for 10v - 36V sensing? on: July 14, 2014, 08:32:41 am
How high, how great a "feedback voltage"?
What is a "feedback voltage"?  Is it short-lived, like a pulse?

Let's say you biased the LED such that with 24V there'd be 10mA.
If there was a 75V feedback voltage, I suppose that for that brief period (big assumption, as I am not versed in the high feedback phenomena) the LED current would be around 30mA.
38  Using Arduino / Programming Questions / Re: Arduino Pro Micro and MAX 3232 on: July 13, 2014, 07:51:14 pm
It's there - as an attachment. No?
Reply #3

The datasheet is at
http://datasheets.maximintegrated.com/en/ds/MAX3222-MAX3241.pdf

Look at page 12, "Typical Operating Circuits", your device is there on the right.
39  Using Arduino / Microcontrollers / Re: atmega 328p works only on arduino board. on: July 13, 2014, 06:46:22 pm
I thought we were developing a list for you.

Let's go with both (there may be more!)
40  Using Arduino / Programming Questions / Re: Arduino Pro Micro and MAX 3232 on: July 13, 2014, 06:38:53 pm
1. The input requires jumpering as the input is a single line TTL input. The data arrives in NRZ format. I have checked this on the Oscilloscope and it works as described. Jumpering is most probably not the issue.  These exact same circuits have been in use for nearly 3 decades and they work just fine.
"They work just fine" on something entirely different.
You stated:
"PIN 13 is connected to RX0 and PIN 14 is connected to TX1 on the Arduino"
Pins 13 and 14 of the MAX232 are supposed to go to the RS232 device (the radio, if it's an RS232 compliant port - Is It?)
The Arduino pins are not RS232 at all - they are TTL/5V.

Refer to the dwg in my previous post (Reply #3)

> > > The only MAXx232 pins that have any business going to any Arduino I/O pin are 9, 10, 11, 12
41  Using Arduino / Microcontrollers / Re: atmega 328p works only on arduino board. on: July 13, 2014, 06:08:38 pm
Reset pulled High (10kΩ).
42  Using Arduino / General Electronics / Re: Reduced phone ringing voltage on: July 13, 2014, 02:41:51 pm
I have, and have used, this
http://www.broadcastboxes.com/pdf/mpc2book.pdf
http://www.broadcastboxes.com/pdf/mpc2prmr.pdf

Presented in the interest/s of education only.
43  Using Arduino / Programming Questions / Re: why do we use int instead of long on: July 13, 2014, 02:22:50 pm
Lots of times we can get by with byte, but the use of int is almost reflexive.
44  Using Arduino / Programming Questions / Re: Arduino Pro Micro and MAX 3232 on: July 13, 2014, 02:21:13 pm
This isn't a laptop.
Perhaps you could explain the merit of jumpering  pin 11 to 12.
Loopback?
I think that presents a problem.

Code:
if(Serial.available() > 0)  // if data from external device presents
{
  byte xcvrdatum = Serial.read();  // put the data somewhere
}
Serial.print(xcvrdatum, HEX);

45  Using Arduino / General Electronics / Re: RFID Readers advice on: July 13, 2014, 11:51:07 am
http://www.parallax.com/product/32390

http://www.parallax.com/downloads/rfid-arduino-example-code
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