I''m a newbie Help me PLEASE - number of pins ?
Archiver
Posts: 46,084
There are three wires going to a serial LCD, but only one of them is
connected to a BASIC Stamp IO pin (this is the serial connection). The
other two pins provide Vdd (+5v) and ground to the display.
If you want to use I2C for more IO, skip the PCF8574 and use the
MCP23016. It has 16 IOs and can sink/source much more current than the
othe device. Watch for the may edition of Nuts & Volts magazine. I use
the MCP23016 to create an I2C LCD interface in my column.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: franksmith512 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=gz8DvYokSMpOXplA7riOEbM5rBah_kL2JbeYyYIeAhrN_kXsrpdeL-jX2fnVXdv91lkcjjTbaclPiklnKyk1wSg]franksmith512@y...[/url
Sent: Saturday, April 17, 2004 12:25 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: I'm a newbie Help me PLEASE - number of pins
?
That raises an interesting question. My software only refers to one
line for the LCD, but I have three wires on my circuit. Am using the
BS2pe which has built-in LCD support. Is the internal software is
using those two other lines?
Sorry, can't test at the moment. That ribbon cable to PCB connection
on the 16X2 LCD is a tad fragile. I need to take time to solder the
wires back on it.
Hopefully, Jon, Tracy or someone else will answer my question.
You can easily do 8 and more buttons/LEDs on a single input using an
I2C bus. I use 3 switches and 2 LEDs all the time on a single
input. That chip is the PCF8574A and is on the NX-1000 24/40 board.
Take care,
Frank
--- In basicstamps@yahoogroups.com, "Dave Mucha" <davemucha@j...>
wrote:
>
> > 1) 3 buttons - would require 3 inputs
> > 2) 2 LEDs - would require 2 outputs ... a clever scheme
might
> use 1 output
> > 3) LCD screen - depends on type could be as little as 3 outputs
> could be
> > several more
> > 4) serial port - unidirectional communication would require 1
input
> or 1 output
> > - bi-directional full duplex communication would
> require 1
> > input and 1 output
> > - bi-directional half duplex communication would
> require 1
> > pin used as an input or output
> >
> >
> > So... your requirements would need to be a processor capable of
> supporting
> > at least 4 I/O's. While the BS1 has 8 I/O's the BS2 has 16
I/O's.
> Keep
> > in mind that there are several relatively easy methods for
> expanding the
> > number of I/O's a processor has to offer. Other things to
consider
> in a
> > processor are speed and ease of programmability.
> >
> >
>
> 4 pins ?
>
> I get 1 pin for the buttons,
> 1 pin for the LED's
> 3 pins for the LCD if it uses a serial bus
> and possibly another set of pins for another serial connection.
>
> If the LCD AND serial can be 2 wire, I can see the 4 pins easily.
>
> but, I get 5, maybe 6 if the LCD can share the serial and each
device
> uses 1 pin for selection, maybe 8 if there are two seperate 3 wire
> serial busses.
>
> what am I missing ?
>
> Dave
connected to a BASIC Stamp IO pin (this is the serial connection). The
other two pins provide Vdd (+5v) and ground to the display.
If you want to use I2C for more IO, skip the PCF8574 and use the
MCP23016. It has 16 IOs and can sink/source much more current than the
othe device. Watch for the may edition of Nuts & Volts magazine. I use
the MCP23016 to create an I2C LCD interface in my column.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: franksmith512 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=gz8DvYokSMpOXplA7riOEbM5rBah_kL2JbeYyYIeAhrN_kXsrpdeL-jX2fnVXdv91lkcjjTbaclPiklnKyk1wSg]franksmith512@y...[/url
Sent: Saturday, April 17, 2004 12:25 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Re: I'm a newbie Help me PLEASE - number of pins
?
That raises an interesting question. My software only refers to one
line for the LCD, but I have three wires on my circuit. Am using the
BS2pe which has built-in LCD support. Is the internal software is
using those two other lines?
Sorry, can't test at the moment. That ribbon cable to PCB connection
on the 16X2 LCD is a tad fragile. I need to take time to solder the
wires back on it.
Hopefully, Jon, Tracy or someone else will answer my question.
You can easily do 8 and more buttons/LEDs on a single input using an
I2C bus. I use 3 switches and 2 LEDs all the time on a single
input. That chip is the PCF8574A and is on the NX-1000 24/40 board.
Take care,
Frank
--- In basicstamps@yahoogroups.com, "Dave Mucha" <davemucha@j...>
wrote:
>
> > 1) 3 buttons - would require 3 inputs
> > 2) 2 LEDs - would require 2 outputs ... a clever scheme
might
> use 1 output
> > 3) LCD screen - depends on type could be as little as 3 outputs
> could be
> > several more
> > 4) serial port - unidirectional communication would require 1
input
> or 1 output
> > - bi-directional full duplex communication would
> require 1
> > input and 1 output
> > - bi-directional half duplex communication would
> require 1
> > pin used as an input or output
> >
> >
> > So... your requirements would need to be a processor capable of
> supporting
> > at least 4 I/O's. While the BS1 has 8 I/O's the BS2 has 16
I/O's.
> Keep
> > in mind that there are several relatively easy methods for
> expanding the
> > number of I/O's a processor has to offer. Other things to
consider
> in a
> > processor are speed and ease of programmability.
> >
> >
>
> 4 pins ?
>
> I get 1 pin for the buttons,
> 1 pin for the LED's
> 3 pins for the LCD if it uses a serial bus
> and possibly another set of pins for another serial connection.
>
> If the LCD AND serial can be 2 wire, I can see the 4 pins easily.
>
> but, I get 5, maybe 6 if the LCD can share the serial and each
device
> uses 1 pin for selection, maybe 8 if there are two seperate 3 wire
> serial busses.
>
> what am I missing ?
>
> Dave