The clearHalt()
method of the USBDevice
interface returns a promise
that resolves when a halt condition is cleared. A halt condition is when a data transfer to or from the device has a status of 'stall'
, which requires the web page (the host system, in USB terminology) to clear that condition. See the for details.
clearHalt(direction, endpointNumber)
The following example shows how to test for and clear a 'stall'
condition in the result of a data transfer.
Note: What data can be passed to a USB device and how it is passed is particular and unique to each device.
while (true) {
let result = await data.transferIn(1, 6);
if (result.data && result.data.byteLength === 6) {
console.log(`Channel 1: ${result.data.getUint16(0)}`);
console.log(`Channel 2: ${result.data.getUint16(2)}`);
console.log(`Channel 5: ${result.data.getUint16(4)}`);
}
if (result.status === "stall") {
console.warn("Endpoint stalled. Clearing.");
await device.clearHalt("in", 1);
}
}