Update README; add example.

README.md

@@ -1,4 +1,73 @@
 BlocksBluetooth
 ========
 
-Block-based CoreBluetooth utilities as categories.
+Block-based CoreBluetooth categories to make your life easier.
+
+This is a pre-release library. v0.0.1 focuses on `CBCentralManager` and `CBPeripheral`, aiming for devices that performs a Central role. On the other hand, only basic `CBPeripheralManager` tasks are covered in this release.
+
+
+## Example
+
+### Scanning for BLE peripherals
+
+```objective-c
+[[CBCentralManager defaultManager] scanForPeripheralsWithServices:nil options:nil didDiscover:^(CBPeripheral *peripheral, NSDictionary *advertisementData, NSNumber *RSSI) {
+    // Handle the returned peripheral
+}];
+```
+
+### Connect to a peripheral, and then recursively discover all its services, characteristics, and descriptors
+
+```objective-c
+__weak typeof(self) weakSelf = self;
+[[CBCentralManager defaultManager] connectPeripheral:self.peripheral options:nil didConnect:^(CBPeripheral *peripheral, NSError *error) {
+    
+    weakSelf.stateLabel.text = weakSelf.peripheral.stateString;
+    
+    // 1A. Read RSSI
+    [peripheral readRSSIAndOnUpdate:^(CBPeripheral *peripheral, NSError *error) {
+        weakSelf.RSSILabel.text = [NSString stringWithFormat:@"RSSI: %@", peripheral.RSSI ?: @"--"];
+    }];
+
+    // 1B. Discover Services
+    [peripheral discoverServices:nil didDiscover:^(NSArray *services, NSError *error) {
+        
+        [weakSelf.tableView reloadData];
+        
+        for (CBService *service in services) {
+            
+            // 2A. Discover Characteristics
+            [peripheral discoverCharacteristics:nil forService:service didDiscover:^(NSArray *characteristics, NSError *error) {
+                [weakSelf.tableView beginUpdates];
+                NSUInteger index = [peripheral.services indexOfObject:service];
+                NSIndexSet *indexSet = [NSIndexSet indexSetWithIndex:index];
+                [weakSelf.tableView reloadSections:indexSet withRowAnimation:UITableViewRowAnimationAutomatic];
+                [weakSelf.tableView endUpdates];
+                
+                for (CBCharacteristic *characteristic in characteristics) {
+
+                    // 3A. Read Value For Characteristic
+                    [peripheral readValueForCharacteristic:characteristic didUpdate:^(CBCharacteristic *characteristic, NSError *error) {
+                        [weakSelf updateTableViewForCharacteristic:characteristic];
+                    }];
+                    
+                    // 3A. Discover Descriptors For Characteristic
+                    [peripheral discoverDescriptorsForCharacteristic:characteristic didDiscover:^(NSArray *descriptors, NSError *error) {
+                        [weakSelf updateTableViewForCharacteristic:characteristic];
+                    }];
+                }
+            }];
+            
+            // 2B. Discover Included Services
+            [peripheral discoverIncludedServices:nil forService:service didDiscover:^(NSArray *services, NSError *error) {
+                //TODO:
+            }];
+        }
+    }];
+    
+} didDisconnect:^(CBPeripheral *peripheral, NSError *error) {
+    
+    weakSelf.stateLabel.text = weakSelf.peripheral.stateString;
+    [[[UIAlertView alloc] initWithTitle:@"Error" message:error.localizedDescription delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil] show];
+}];
+```