Ok, not much help then...
It looks like you may want to use I2C_START,
and ACK is the default. The ADDR_8BITS_FLAG
was a bad idea that seems to have been corrected.
I expect that you would provide the actual
I2C bus address and the system will shift it
and add the read/write bit as needed.
But the best thing is to use the code as the
documentation...also google "I2C spec" and
get something to compare it to. I ended up
with a logic analyzer on the bus to get it
right, but that was mostly due to the
missing "wait-state" issue with my hardware.
Sorry, but I don't understand your multiple-
STARTS thing. AFAIK a START and STOP delineates
a packet and there is no higher level encapsulation.
But again, let the spec be your guide.
MS
Ronald Eliseo Reyes López wrote:
> Hi MS.
>
> Thanks for answer...
>
> The T2 impl is not like the T1 version, more explicitly... I want to use
> the Msp430I2CC.nc configuration that provide the I2CPacket.nc, this
> interface use the header file I2C.h where there are defined this flags:
>
> #ifndef _I2C_H
> #define _I2C_H
>
> typedef struct { } TI2CExtdAddr;
> typedef struct { } TI2CBasicAddr;
>
> typedef uint8_t i2c_flags_t;
>
> enum {
> I2C_START = 0x01,
> I2C_STOP = 0x02,
> I2C_ACK_END = 0x04,
> };
>
>
> #endif /* _I2C_H */
>
> Now I have doubts about how to put address slave and how to use this
> flags for write/read operations, and the slave address is 8 bits
> (included the lsb w/r).
> Also I need impl "multiple repeated STARTs and multiple reads/writes
> within the same START transaction".
>
> I hope do you understand my problem, thaks...
>
>
> 2010/5/18 Michael Schippling <[email protected] <mailto:[email protected]>>
>
> If the T2 impl is like the T1 version there are four bits
> you can send to I2C read/write, which are conveniently
> not defined or described anywhere:
>
> /*
> ** I2CPacket read/write command flags,
> ** defined in I2CPacketM.nc but not in a header file...
> */
> #define STOP_FLAG 0x01 //send stop/end command at the
> // end of the packet
> #define ACK_FLAG 0x02 //ack every byte except for the
> // last received
> #define ACK_END_FLAG 0x04 //acks after the last byte read
> #define ADDR_8BITS_FLAG 0x80 //slave address is a full eight
> // bits as sent. w/this bit user
> // must set read flag explicitly
>
> Through exhaustive testing and spec reading I found that these
> two needed to be set for my external device. I believe they
> are both the default expected I2C behavior so why they are
> non-default options is left as an exercise for the reader:
>
> // works...no END ACK...dunno?
> #define I2CP_I2CFLAGS (STOP_FLAG | ACK_FLAG)
>
> Also watch out for "wait-state" handshakes between bytes on
> the I2C bus. The T1 code doesn't detect them and can over run.
> If you read one byte correctly then part of another and
> nothing more you may need to extend the timeout between
> bytes in I2CM.nc
>
> MS
>
>
>
>
> Ronald Eliseo Reyes López wrote:
>
>
> ---------- Forwarded message ----------
> From: *Philip Levis* <[email protected]
> <mailto:[email protected]> <mailto:[email protected]
> <mailto:[email protected]>>>
> Date: 2010/5/17
> Subject: Re: Help with I2CPacket.nc
> To: Ronald Eliseo Reyes López <[email protected]
> <mailto:[email protected]> <mailto:[email protected]
> <mailto:[email protected]>>>
> Cc: [email protected] <mailto:[email protected]>
> <mailto:[email protected]
> <mailto:[email protected]>>, [email protected]
> <mailto:[email protected]> <mailto:[email protected]
> <mailto:[email protected]>>
>
>
> Please send questions to tinyos-help. Thanks!
>
> Phil
>
> On May 16, 2010, at 5:21 PM, Ronald Eliseo Reyes López wrote:
>
> > Hi.
> >
> > I'm a student and I need to control an pressure sensor,
> exactly BMP085 from Bosch Sensortec, for my tesis degree.
> > This sensor use I2C protocol to communicate with master,
> which will be a Telosb mote.
> >
> > The problem is I don't understand how to use the i2c_flags
> with the I2CPAcket's command read. The explanation is not enouhg
> seem me, please anybody can help me?
> >
> > I have the new version of tinyos-2.x from cvs repository.
> >
> > thanks in advance, and i hope your answer.
> >
> > Ronald Reyes
>
>
>
>
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>
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>
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