Hi,
I'm using the "pc-ble-driver-js" to implement a central on PC, trying to send a file through a Write w/o Response characteristic to a device. It's OK for a small file (eg. 4KB), but when I try to send a large file, it will break randomly, eg. after several tenth KB.
The error message is: Failed to write to attribute with handle: 23: Timed out when waiting for BLE_EVT_TX_COMPLETE.
After occurs, the connection keep but any other message (no matter short or long) will not be send to device, unless I disconnect and reconnect it.
I'm using the NodeJS 8.15.1, PCA10031 dongle with v2 SD_API_VERSION.
This is what I send the data out, anything I did it wrong? Thanks
async function sendBurst(data)
{
let offset = 0;
let seq = 0;
let txBuf;
let i;
while (true)
{
i = data.length - offset; // no. of byte need to send in this round
// Prepare the txBuf[]
if (offset === 0)
{
// First packet
if (i > 20)
i = 20;
txBuf = data.slice(0, offset + i);
txBuf[0] = (data[0] & 0x0f) | (seq << 4); // insert "seq" into [CMD1]
}
else
{
// Remaining Packet
if (i > 19)
i = 19;
txBuf = data.slice(offset, offset + i);
txBuf.unshift(seq << 4); // insert "seq" into txBuf[0]
}
seq ++;
if (seq >= 7)
seq = 1;
offset += i;
if (offset >= data.length)
{
txBuf[0] |= 0x80;
seq = 0xff;
}
// Send it now
await new Promise((resolve, reject) => {
adapter.writeCharacteristicValue(charID_burstTx, txBuf, false, (err) => {
if (err)
{
reject(err);
return;
}
resolve();
});
});
if (seq == 0xff)
break; // abort if all send
}
}
