Hi,
I was able to solve the problem:
I noticed that there was something wrong with the uint16 field: I
programmed the mote to unpack the message and pack it in another one to
be sent back to the computer. If I sent 0x0a05 the return message would
be 0x0a00. I tried to divide the uint16 field in two uint8 fields (high
and low), and with that everything worked.
To cut a long story short, after a long hours of desperation, I did the
simplest thing I could think of. If my message structure was:
struct DimmerControlMSG
{
uint8_t todo;
uint16_t val;
};
I changed it for:
struct DimmerControlMSG
{
uint16_t val;
uint8_t todo;
};
And now everything's working!!
Any comments on this? Is this something which happens often?
-Jose.
On Tue, 2006-03-21 at 18:04 +0100, Jose L. Ponce wrote:
> Hi all,
>
> I want to control the DAC of my telosb mote using commands from the
> computer through the USB port. For that, I've programmed an application
> which receives a message with two fields: uint8_t for the command and
> uint16_t for the value we want to set the DAC to.
>
> There are two commands: set (1), with a value, to set the DAC, and show,
> without a value, to see to which value the DAC is set to (when issuing a
> set command, the mote returns the DAC value as well).
>
> On the computer side, the commands are issued using a small java
> application:
>
> java Dimmer set X
> java Dimmer show
>
> The problem is that the value field (uint16_t) is not recognised: I will
> issue java Dimmer set 10 ten times and each time I will get a different
> DAC output and a different return value from the mote. I have tried to
> modify my message type and have the value field as a uint8_t. In this
> way, issuing a set command from 0 to 256 will give me right values.
> Above that, it doesn't seem to work anymore.
>
> Can anyone enlighten me a little on what I am doing wrong? It'd be much
> appreciated.
>
> Below I include the relevant code.
>
> Thanks,
>
> - Jose.
>
> // DimmerControlM.nc (on the mote)
> // DimmerControlMSG has two fields: todo (uint8_t) and value (uint16_t)
>
> task void sendMsg(){
> struct DimmerControlMSG* sen;
> sen = (struct DimmerControlMSG *)outw.data;
> sen->value = value;
>
> call SendMsg.send( TOS_UART_ADDR, sizeof(struct DimmerControlMSG),
> &outw);
> }
>
> event TOS_MsgPtr ReceiveMsg.receive( TOS_MsgPtr inw ){
> struct DimmerControlMSG* rec;
> rec = (struct DimmerControlMSG *)inw->data;
>
> if( rec->todo & 0x1 ) {
> value=rec->value;
> if(call DAC.output(value) == SUCCESS)
> call Leds.redToggle();
> }
>
> post sendMsg();
> return inw;
> }
>
>
> _______________________________________________
> Tinyos-help mailing list
> [email protected]
> https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
>
_______________________________________________
Tinyos-help mailing list
[email protected]
https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
