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241  Using Arduino / General Electronics / Re: Do I need to limit current to IC's? on: November 12, 2012, 10:47:03 am
Mike I no what HC stands for but Most all of the HC chips or as a fact all of the HC chips I've used use far more current then any of the LS chips

Take a 74HC164 and the 74LS164 shift registers
Quote
The 74HC164; 74HCT164 are high-speed Si-gate CMOS devices and are pin compatible
with Low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC164
Code:
Table 4. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol Parameter Conditions Min Max Unit
VCC supply voltage 0.5 +7 V
IIK input clamping current VI < 0.5 V or VI > VCC + 0.5 V [1] - 20 mA
IOK output clamping current VO < 0.5 V or VO > VCC + 0.5 V [1] - 20 mA
IO output current 0.5 V < VO < VCC + 0.5 V - 25 mA
ICC supply current - 50 mA
IGND ground current 50 - mA
Tstg storage temperature 65 +150 C

Now the 74LS164
Code:
over recommended operating free air temperature range (unless otherwise noted)
Note 3: All typicals are at VCC = 5V, TA = 25°C.
Note 4: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 5: ICC is measured with all outputs OPEN, the SERIAL input grounded, the CLOCK input at 2.4V, and a momentary ground, then 4.5V, applied to the
CLEAR input.
Switching Characteristics
at VCC = 5V and TA = 25°C
Supply Voltage 7V
Input Voltage 7V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range -65°C to +150°C
Symbol Parameter Min Nom Max Units
VCC Supply Voltage 4.75 5 5.25 V
VIH HIGH Level Input Voltage 2 V
VIL LOW Level Input Voltage 0.8 V
IOH HIGH Level Output Current -0.4 mA
IOL LOW Level Output Current 8 mA
fCLK Clock Frequency (Note 2) 0 25 MHz
tW Pulse Width Clock 20
ns
(Note 2) Clear 20
tSU Data Setup Time (Note 2) 17 ns
tH Data Hold Time (Note 2) 5 ns
tREL Clear Release Time (Note 2) 30 ns
TA Free Air Operating Temperature 0 70 °C
Symbol Parameter Conditions Min
Typ
(Note 3) Max Units
VI Input Clamp Voltage VCC = Min, II = -18 mA -1.5 V
VOH HIGH Level VCC = Min, IOH = Max
2.7 3.4 V
Output Voltage VIL = Max, VIH = Min
VOL LOW Level VCC = Min, IOL = Max
0.35 0.5
Output Voltage VIL = Max, VIH = Min V
IOL = 4 mA, VCC = Min 0.25 0.4
II Input Current @ Max Input Voltage VCC = Max, VI = 7V 0.1 mA
IIH HIGH Level Input Current VCC = Max, VI = 2.7V 20 mA
IIL LOW Level Input Current VCC = Max, VI = 0.4V -0.4 mA
IOS Short Circuit Output Current VCC = Max (Note 4) -20 -100 mA
ICC Supply Current VCC = Max (Note 5) 16 27 mA

You tell me which is backward The LS uses less power can output less power or is current not related to power?"
242  Using Arduino / General Electronics / Re: Do I need to limit current to IC's? on: November 12, 2012, 09:58:39 am
@ fungus
Quote
Do you think "HC" means High Current...?

This is 74HC D-Type Flip-Flop
Quote
Eight D-Type Flip-Flops in a Single Package
 High-Current 3-State True Outputs Can
Drive up to 15 LSTTL Loads
And the 74LS D-Type Flip-Flop uses half the current
But to answer you HC and high current go hand in hand.  

And @ FunkyJive you do not limit Current to these chips they will only use what they need
Now if you had ask do you keep there output's from drawing to much Current then the answer would be Yes.

If the output pins are rated at 20mA as most 74HC chips are and the load is leds you would limit it
to 20mA a led
But if your switching a load that draws little or no power Like the data pins of a LCD then there's no need to limit anything.
243  Using Arduino / General Electronics / Re: Do I need to limit current to IC's? on: November 12, 2012, 06:09:30 am
This is totally wrong 
Quote
So 74HCxx series will be just fine.  If using older TTL chips (74xx and 74LSxx series) then you may find you have an issue with power

Your backward here

74LSxxx means low power 74HCXXX are high power chips they can use way more power the a LS chip.

Let's take a 74LS164 it supply current  is  27mA it's output per pin is 8 mA

Now take 74HC164 it's supply current is 50mA it's output per pin is 20 mA
244  Using Arduino / Programming Questions / Re: Time Libraries on: November 11, 2012, 05:35:30 pm
While I think I found that to just need to figure where to put this

Code:
time = millis();
to fix it
245  Using Arduino / Programming Questions / Re: Time Libraries on: November 11, 2012, 05:10:50 pm
Ok it should be simple but there not any thing that shows how to handle a byte.
Looks like it would be done this way
Code:
Serial.write( TIME_HEADER);
Now for next problem
Code:
C:\Documents and Settings\Burt\My Documents\Downloads\arduino-1.0.2-windows\arduino-1.0.2\libraries\DateTime\DateTime.cpp: In member function 'void DateTimeClass::setTime(time_t)':
C:\Documents and Settings\Burt\My Documents\Downloads\arduino-1.0.2-windows\arduino-1.0.2\libraries\DateTime\DateTime.cpp:28: error: 'millis' was not declared in this scope
C:\Documents and Settings\Burt\My Documents\Downloads\arduino-1.0.2-windows\arduino-1.0.2\libraries\DateTime\DateTime.cpp: In member function 'time_t DateTimeClass::now()':
C:\Documents and Settings\Burt\My Documents\Downloads\arduino-1.0.2-windows\arduino-1.0.2\libraries\DateTime\DateTime.cpp:43: error: 'millis' was not declared in this scope
246  Using Arduino / Programming Questions / Re: Time Libraries on: November 11, 2012, 03:11:43 pm
Well  just got done going over the file and this may be the cause of the problem
Code:
{
  Serial.print(TIME_REQUEST,BYTE); 
  return 0; // the time will be sent later in response to serial mesg
}
247  Using Arduino / Programming Questions / Re: Time Libraries on: November 11, 2012, 03:06:58 pm
Well I just looked at the libraries for Date Time and there casting byte to uint8_t so that shouldn't be a problem

And Yes I'm trying the sample for Timeserial so it may be just the sample.

248  Using Arduino / Programming Questions / Time Libraries on: November 11, 2012, 02:41:28 pm
I was wanting to use the time libraries But they don't play nice with arduino 1.0.1 or 1.0.0
And the Date time libraries has byte used in the serial part which keeps it from working.

Here what I get
Quote
sketch_nov11a.cpp: In function 'void loop()':
sketch_nov11a:31: error: 'BYTE' was not declared in this scope

As of Arduino 1.0, the 'BYTE' keyword is no longer supported.
Please use Serial.write() instead.


And here the Time sample
Quote
TimeSerial.cpp: In function 'time_t requestSync()':
TimeSerial.pde:-1: error: 'BYTE' was not declared in this scope

As of Arduino 1.0, the 'BYTE' keyword is no longer supported.
Please use Serial.write() instead.


249  Using Arduino / General Electronics / Re: 7805 IC Regulator outputting 9v. on: November 08, 2012, 11:58:18 pm
He is feeding some back with R1 so he could be getting 9 volts
250  Using Arduino / General Electronics / Re: Trying to understand pull-up resistors on: November 07, 2012, 05:52:40 pm
Your totally wrong here the DS18B20 is one wire the resistor is used to hold the line high when the chip is not sending data.

The ardunio send out a call for the DS18B20 and it send back that its on the line after is sees that the Line is high it sends data. Then when the line is high the ardnuio can send to the DS18B20 what it wants if it needs to set the chip or just let the chip tell how hot or cold it it is.
251  Using Arduino / Project Guidance / Re: Guidance on an outdoor surveillance application on: October 31, 2012, 10:44:39 am
I don't no if this would work for you but I used a CCD camera It has 10 IR leds so it can see at night.

This is what these things can do It will output a voltage change when you move, but it's read able you could tell what is in front of it.



It could do what you want I hooked the power to 5 volts and used ADC to read the video and you get movement readings
that change with size and heat.

And there repeatable
252  Using Arduino / Project Guidance / Re: TX/RX pin and serial communication on: October 30, 2012, 10:01:42 am
This may help you Plug the uno to your PC load a blink sketch now when it
gets to where it tells program Memory used at the bottom of the IDE press the reset button and let it go.

That should let the boot loader take over. And should program you may have to do more then one time to get the timing right But if you chip didn't
blow the pins TX and RX it should work.

The boot loader starts first then your program so if you reset it will give you a little more time so the boot loader can take over before your program loads. 
253  Using Arduino / Project Guidance / Re: What do I need ?! on: October 30, 2012, 09:01:27 am
You would get better help if you had named this telling what your making
I would ask a mod to change the name

To something like this

What parts do I need to make a money collecting machine.

Not really much less you want to count the money. So most of what you add to it is really for show. I would think of added blinking LED's to cache peoples eyes so they drop in some money.
254  Using Arduino / General Electronics / Re: AMS1117 3.3v volt regulator draws power when bypassed on: May 28, 2012, 09:35:59 pm
I guess you did post that But there was the same thing posted by Jon. That site you can't tell who did what it's changed to much. Still great idea majenko not new but Nice

The OP can use smd part it would be very small foot print.
255  Using Arduino / General Electronics / Re: AMS1117 3.3v volt regulator draws power when bypassed on: May 28, 2012, 02:13:49 am
John posted how to use a diode without voltage drop over here http://digital-diy.com/forum/general-electronics/mini-tip-diode-without-a-voltage-drop-t2206.html#p13262
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