simple LED sequence

Ash
Guest

Sat Feb 25, 2006 5:13 pm

Hello

I am attempting to create a basic LED sequence

On Pulse
LED 1 - ON
Pause 5 mins
LED 2 - ON
Pause 5 mins
LED 3 - ON
Pause 5 mins
LED 4 - ON
Pause 5 mins
LED 5 - ON

I was considering using a PIC but with no knowledge of PIC programming,
and after having read a beginners guide to it I feel that it may be too
complicated.

Is there an easier way to produce this sequence without using multiple
logic gates? or a simple method of progamming a PIC to perform this
function

Thanks

Ash

John Fields
Guest

Sat Feb 25, 2006 10:42 pm

On 25 Feb 2006 08:13:38 -0800, "Ash" <ashleyyouett_at_hotmail.com>
wrote:

Quote:

Hello

I am attempting to create a basic LED sequence

On Pulse
LED 1 - ON
Pause 5 mins
LED 2 - ON
Pause 5 mins
LED 3 - ON
Pause 5 mins
LED 4 - ON
Pause 5 mins
LED 5 - ON

I was considering using a PIC but with no knowledge of PIC programming,
and after having read a beginners guide to it I feel that it may be too
complicated.

Is there an easier way to produce this sequence without using multiple
logic gates? or a simple method of progamming a PIC to perform this
function

---
Well, you've gotta build it out something, so here's a 2 chip
solution for ya. Spare the extra nand gates by connecting their
inputs to Vcc or GND, and view in Courier:

..+5V>------+----+
.. | |
.. | [1M]
.. | |
.. [1500R] |
.. | +----|-\
.. | | | >----[<LED5]--[1500R]--+5v
.. +----|----|+/
.. | | LM339A
.. | |
.. [536R] |
.. | +----|-\
.. | | | >----[<LED4]--[1500R]--+5v
.. +----|----|+/
.. | | B
.. | |
.. [715R] |
.. | +----|-\
.. | | | >----[<LED3]--[1500R]--+5v
.. +----|----|+/
.. | | C
.. | |
.. [953R] |
.. | +----|-\
.. | | | >----[<LED2]--[1500R]--+5v
.. +----|----|+/
.. | | D
.. | | +-[<LED1]--[1500R]--+5v
.. [1300R] | |
.. | +-----D | B------+ +5
.. | |+ G--+--+--Y NAND | |
.. | [1000µF] S | A--+ | [1M]
.. | | | | | | |
..GND>------+----+-----+ +--B | +---+
.._____ NAND Y--+ | |
..START>--------------------------A | [0.1]
.. | |
.._____ | GND
..RESET>------------------------------------+

The 1000µF cap needs to be a low-leakage electroyrolytic like a
Nichicon KL series, and the LEDs need to be high-efficiency types
like HLMP-4700.

Since the 1000µF cap is +/- 20%, you may want to change the 1 megohm
timing cap to a pot in series with a fixed resistor if you need any
kind of precision at all.

Or, do it with a µC. ;)

--
John Fields
Professional Circuit Designer

John Fields
Guest

Sat Feb 25, 2006 11:08 pm

On Sat, 25 Feb 2006 15:42:03 -0600, John Fields
<jfields_at_austininstruments.com> wrote:

Quote:

On 25 Feb 2006 08:13:38 -0800, "Ash" <ashleyyouett_at_hotmail.com
wrote:

Hello

I am attempting to create a basic LED sequence

On Pulse
LED 1 - ON
Pause 5 mins
LED 2 - ON
Pause 5 mins
LED 3 - ON
Pause 5 mins
LED 4 - ON
Pause 5 mins
LED 5 - ON

I was considering using a PIC but with no knowledge of PIC programming,
and after having read a beginners guide to it I feel that it may be too
complicated.

Is there an easier way to produce this sequence without using multiple
logic gates? or a simple method of progamming a PIC to perform this
function

---
Well, you've gotta build it out something, so here's a 2 chip
solution for ya. Spare the extra nand gates by connecting their
inputs to Vcc or GND, and view in Courier:

.+5V>------+----+
. | |
. | [1M]
. | |
. [1500R] |
. | +----|-\
. | | | >----[<LED5]--[1500R]--+5v
. +----|----|+/
. | | LM339A
. | |
. [536R] |
. | +----|-\
. | | | >----[<LED4]--[1500R]--+5v
. +----|----|+/
. | | B
. | |
. [715R] |
. | +----|-\
. | | | >----[<LED3]--[1500R]--+5v
. +----|----|+/
. | | C
. | |
. [953R] |
. | +----|-\
. | | | >----[<LED2]--[1500R]--+5v
. +----|----|+/
. | | D
. | | +-[<LED1]--[1500R]--+5v
. [1300R] | |
. | +-----D | B------+ +5
. | |+ G--+--+--Y NAND | |
. | [1000µF] S | A--+ | [1M]
. | | | | | | |
.GND>------+----+-----+ +--B | +---+
._____ NAND Y--+ | |
.START>--------------------------A | [0.1]
. | |
._____ | GND
.RESET>------------------------------------+

The 1000µF cap needs to be a low-leakage electroyrolytic like a
Nichicon KL series, and the LEDs need to be high-efficiency types
like HLMP-4700.

Since the 1000µF cap is +/- 20%, you may want to change the 1 megohm
timing cap to a pot in series with a fixed resistor if you need any
kind of precision at all.

Or, do it with a µC. Wink

---
Thinking about it a little bit more, if you were to replace the
fixed 1 megohm timing resistor with a pot and you adjusted it to
make the first five minute timing interval accurate, then all of the
other intervals would also be closer to what you're looking for.

--
John Fields
Professional Circuit Designer

simple LED sequence

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