Are you facing difficulties when trying to read characteristics using the Flutter Blue plugin? Don’t worry, you’re not alone. In this comprehensive guide, we’ll explore the common issues faced while reading characteristics and provide effective solutions to help you overcome them.
Understanding the Problem
When using the Flutter Blue plugin to read characteristics values, you may encounter an error that prevents you from obtaining the desired output. The error message you may encounter is: “Unhandled Exception: PlatformException(read_characteristic_error, unknown reason, may occur if readCharacteristic was called before the last read finished., null)”.
The Read Characteristics Process
To better understand the issue, let’s take a look at the code snippet responsible for reading the characteristics:
code
readCharacteristics() {
device.discoverServices().then((services) {
services.forEach((_service) {
_service.characteristics.forEach((c) {
device.readCharacteristic(c).then((value) {
print('value is $value');
});
});
});
});
}
The readCharacteristics()
function initiates the reading process by discovering services and iterating through the characteristics. However, the error occurs when trying to read the characteristics asynchronously.
Solution: Synchronize Read Operations
To resolve the issue, you need to ensure that read operations are performed synchronously. Simultaneous reads can lead to conflicts and errors. Here’s a suggested solution to synchronize the read operations:
dartCopy code
readCharacteristics() async {
for (final service in device.services) {
for (final characteristic in service.characteristics) {
await device.readCharacteristic(characteristic);
// Process the read value here
}
}
}
By using the for-in
loop instead of forEach
, and awaiting the readCharacteristic()
method within the loop, you can ensure that each read operation is completed before moving on to the next one. This helps prevent conflicts and ensures a smooth reading process.
Conclusion
The Flutter Blue plugin provides powerful capabilities for reading characteristics, but encountering errors during the process can be frustrating. By synchronizing your read operations and implementing the suggested solution, you can overcome the “read_characteristic_error” and obtain the desired characteristic values successfully.
Remember, troubleshooting and debugging are essential skills in the world of programming. With the right approach and patience, you can overcome any obstacles you encounter while working with the Flutter Blue plugin.