Call async function in a while loop

Question

I have to read a value from a BLE devive and then write to it another value so this is my function to do it:

   getBit = (device) => {
        try {
            device.readCharacteristicForService(this.state.sUuid, this.state.cUuid2)
            .then((read) => {
                switch (this.toHexByte(read.value)) {
                    case 'ee':
                        this.setState({ countC0: 0 });
                        break;
                    case 'c0':
                        this.setState({ countC0: this.state.countC0 + 1 });
                        break;
                    default: // the bit I want to stock
                        this.setState({
                            resId: [...this.state.resId, this.toHexByte(read.value)],
                            countC0: 0
                        });
                        break;
                }
                device.writeCharacteristicWithoutResponseForService(this.state.sUuid, this.state.cUuid2, this.state.respBit)
            })
            return
        }
        catch (err) {
            console.log("find catch error:", err);
        }
    }

but I have to call this function until I get the same bit ('c0') 3 time so I loop for it like that:

   while (countC0 < 15) {
     this.getBit(device);
     countC0++;
   }

The problem is that I receive Please report: Excessive number of pending callbacks: 501 error because I'm calling an async function in a while loop.

score 1 · Accepted Answer · answered Dec 26 '21 at 17:24

This should do it

getBit = async (device) => {
    try {
        const read = await device.readCharacteristicForService(this.state.sUuid, this.state.cUuid2)


        switch (this.toHexByte(read.value)) {
            case 'ee':
                this.setState({ countC0: 0 });
                break;
            case 'c0':
                this.setState({ countC0: this.state.countC0 + 1 });
                break;
            default: // the bit I want to stock
                this.setState({
                    resId: [...this.state.resId, this.toHexByte(read.value)],
                    countC0: 0
                });
        }

        device.writeCharacteristicWithoutResponseForService(this.state.sUuid, this.state.cUuid2, this.state.respBit)
    }
    catch (err) {
        console.log("find catch error:", err);
    }
}

  while (countC0 < 15) {
     await this.getBit(device);
     countC0++;
   }

Call async function in a while loop

1 Answers1