WiiLi.org

[schogla]

What is the temporal resolution of the wiimote? anyone know

am doing some stuff with The AKAwiiremote in max msp and it appears that at most it seems to be packets of data at 100hz or 30 hz

can that be right?? I know for gaming less sensitve info is needed due to the 50 hz refresh rate of most screens but it seesm an aweful waste if it isonly giving new info every 30ms

??

ANy ideas

[wic]

The wiimote sends data at a maximum rate of 100Hz. There are two modes: continuous or "when-changed". Continuous gives you a constant 100Hz. When-changed sends data each time a new button/ir/acc reading has changed, also maximum of 100hz.

[schogla]

Hi thanks - I am currently using the MAXMSP object for accessing wii accel data - have calibratyed it to real world values and it is not bad

I have noted thet in teh source code in Wiimote.c there is the following
stipulation in the code for 10ms is it possible to change this here to up thew resolution?

I am not much of a programer but a motion researcher studying performance etc.... any ideas all.

I will post my calibration results in another thread I started a while back

B




"Boolean wiiremote_connect(WiiRemoteRef wiiremote)
{
IOReturn ret;
short i;

if (wiiremote->device == nil)
return false;

// connect the device
for (i=0; i<kTrial; i++)
{
ret = IOBluetoothDeviceOpenConnection(wiiremote->device, nil, nil);
if ( ret == kIOReturnSuccess)
break;
usleep(10000); // wait 10ms
}
if (i==kTrial)
return false;

wiiremote->disconnectNotification = IOBluetoothDeviceRegisterForDisconnectNotification(wiiremote->device, myDisconnectedFunc, (void *)wiiremote);

// performs an SDP query
for (i=0; i<kTrial; i++)
{
ret = IOBluetoothDevicePerformSDPQuery(wiiremote->device, nil, nil);
if ( ret == kIOReturnSuccess)
break;
usleep(10000); // wait 10ms
}
if (i==kTrial)
return false;

// open L2CAPChannel : BluetoothL2CAPPSM = 17
for (i=0; i<kTrial; i++)
{
ret = IOBluetoothDeviceOpenL2CAPChannelSync(wiiremote->device, &(wiiremote->cchan), 17, myEventListener, (void *)wiiremote);
if ( ret == kIOReturnSuccess)
break;
usleep(10000); // wait 10ms
}
if (i==kTrial)
{
wiiremote->cchan = nil;
IOBluetoothDeviceCloseConnection(wiiremote->device);
//wiiremote->device = nil; // remove in B5
return false;
}
IOBluetoothObjectRetain(wiiremote->cchan); // add in B5

// open L2CAPChannel : BluetoothL2CAPPSM = 19
for (i=0; i<kTrial; i++)
{
ret = IOBluetoothDeviceOpenL2CAPChannelSync(wiiremote->device, &(wiiremote->ichan), 19, myEventListener, (void *)wiiremote);
if ( ret == kIOReturnSuccess)
break;
usleep(10000); // wait 10ms
}
if (i==kTrial)
{
wiiremote->ichan = nil;
IOBluetoothL2CAPChannelCloseChannel(wiiremote->cchan);
IOBluetoothObjectRelease(wiiremote->cchan); // add in B5
IOBluetoothDeviceCloseConnection(wiiremote->device);
//wiiremote->device = nil; // remove in B5
return false;
}
IOBluetoothObjectRetain(wiiremote->ichan); // add in B5

wiiremote_motionsensor(wiiremote, true);
wiiremote_irsensor(wiiremote, false);
wiiremote_vibration(wiiremote, false);
wiiremote_led(wiiremote, false, false, false, false);
wiiremote_expansionport(wiiremote, false);

for(i = 0; i< kTrial; i++) // add in B5
{
readData(wiiremote, 0x0010, 16);
usleep(10000); // wait 10ms
}

return true;
}

[wic]

Hi

I'm afraid the maximum output from the wiimote is 100Hz. At least we dont know any way to change that. The limitation is definately in the wiimote. I dont know about the code you posted, using sleeps seems odd to me. Anyway, the rate it easy to measure: put the wiimote in continuous mode, (or just spin the wiimote on its strap) then count the samples for a few seconds and divide that number by the time. If you dont get 100samples/sec, then your software is doing it wrong.

Btw, I am very interested in hearing about any results you can get out of the wiimote regarding precision, calibration etc. So if you have anything, dont hesitate to post your results and conclusions!