Mcp23016

Archiver

If I write:

I2COUT SDA, Wr23016, GP0, [noparse][[/noparse]dataGP0] 'dataGP0 = %10101010 = 170

will that set the states of GP0.0 to GP0.7, i.e., 0, 2, 4 and 6 high, 1, 3, 5
and 7 low?

Same for GP1?

Sid


[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

When writing to the MCP23016 you must set the DDR bits for each port.
To make all the pins on GP0 outputs you would do this:

I2COUT SDA, Wr23016, IODIR0, [noparse][[/noparse]%00000000]

In the MCP23016 DDR registers, zero indicates an output (0 looks like
O), one indicates an input (1 looks like I).

After that, writing a 0 to a GPx port pin makes it low, 1 makes it high.
So in your example below, writing %10101010 to GP0 would cause GP0.0,
GP0.2, GP0.4, and GP0.6 to be low, the others to be high.

-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office

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Original Message

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From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=uyWBiR5gntY2KxVVFClmJvUc38xPSYU3A-Bn8ExPFKd-1A5pNPQ2P5jlFYjdJHgBV3E0MfSi]Newzed@a...[/url
Sent: Saturday, April 10, 2004 3:38 PM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] MCP23016


If I write:

I2COUT SDA, Wr23016, GP0, [noparse][[/noparse]dataGP0] 'dataGP0 = %10101010 = 170

will that set the states of GP0.0 to GP0.7, i.e., 0, 2, 4 and 6 high, 1,
3, 5
and 7 low?

Same for GP1?

Sid

Archiver

In a message dated 4/11/2004 7:32:54 PM Eastern Daylight Time,
jwilliams@p... writes:


> After that, writing a 0 to a GPx port pin makes it low, 1 makes it high.
> So in your example below, writing %10101010 to GP0 would cause GP0.0,
> GP0.2, GP0.4, and GP0.6 to be low, the others to be high.
>
>

The data sheet says the bytes are send MSB. So if I send 1000 000 does the
"1" go to GPO.0 or GP0.7? You would think it would go to GP0.0, like a shift
register.

Sid


[noparse][[/noparse]Non-text portions of this message have been removed]

Archiver

The transmission of the data is handled by I2COUT and has no affect on
your data bytes. So long as you have everything configured properly,
sending %10101010 will make bits GPx.1, GPx.3, GPx.5, and GPx.7 high,
the others low.

-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office

---

Original Message

---

From: Newzed@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=nYBUsl8_vrDZp5wQEf-v0siOKLgPBhhOro2FlSSdURuFQQhK7aEhyC1M3IXyi1n8ehzVlQ]Newzed@a...[/url
Sent: Sunday, April 11, 2004 7:02 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] MCP23016


In a message dated 4/11/2004 7:32:54 PM Eastern Daylight Time,
jwilliams@p... writes:


> After that, writing a 0 to a GPx port pin makes it low, 1 makes it
> high. So in your example below, writing %10101010 to GP0 would cause
> GP0.0, GP0.2, GP0.4, and GP0.6 to be low, the others to be high.
>
>

The data sheet says the bytes are send MSB. So if I send 1000 000 does
the
"1" go to GPO.0 or GP0.7? You would think it would go to GP0.0, like a
shift
register.

Sid