Raspberry Pi 4用作BLE中央设备连接问题
Raspberry Pi 4 used as BLE central device connection issues
对于专业项目，我必须使用 RPI4 作为中央设备来连接到特定的外围设备。
为了进行测试，我开发了一个程序来模拟 RPi 上的外围设备（感谢 bleno Node.js 模块），方法是设置一个 GATT 服务器，并使用另一个 RPi 作为我的中心和 bluepy Python 库。
一切正常，但是当我在外围设备上将广告间隔设置为高于 4000 毫秒时，连接不再有效（即使在 RPi GATT 服务器或生产服务器上）。
我尝试在我的中心问题上使用 gatttool/hcitool，它运行良好，但前提是广告间隔小于 4000 毫秒。
但是当我尝试使用我的 phone 和专用应用程序（nRF 连接）连接到我的 GATT 服务器时它起作用了。
经过一番研究，我发现Linux内核只验证7.5ms - 4000ms（https://lkml.org/lkml/2019/8/2/358）范围内的连接间隔值，这与我的实验值完全吻合。但是除非我对 BLE 不了解，否则连接间隔和广告间隔是完全独立的，这应该不是问题。在蓝牙文档中，我发现最大广告间隔值应该是 10240ms。有点不明白
这是我的 GATT 服务器 运行 在一个 RPi4 上，如果你想重现的话。
我使用 sudo BLENO_ADVERTISING_INTERVAL=xxxx node my_gatt_server.js 开始它，xxxx 是我想要的以毫秒为单位的广告间隔。
var bleno = require('bleno');
// Once bleno starts, begin advertising our BLE address
bleno.on('stateChange', function(state) {
console.log('State change: ' + state);
if (state === 'poweredOn') {
bleno.startAdvertising('MyDevice',['6d79686561727473656e74696e656c10']);
} else {
bleno.stopAdvertising();
}
});
// Notify the console that we've accepted a connection
bleno.on('accept', function(clientAddress) {
console.log("Accepted connection from address: " + clientAddress);
});
// Notify the console that we have disconnected from a client
bleno.on('disconnect', function(clientAddress) {
console.log("Disconnected from address: " + clientAddress);
});
// When we begin advertising, create a new service and characteristic
bleno.on('advertisingStart', function(error) {
if (error) {
console.log("Advertising start error: " + error);
} else {
console.log("Advertising start success");
bleno.setServices([
// Define a new service
new bleno.PrimaryService({
uuid : '6d79686561727473656e74696e656c10',
characteristics : [
// ECG characteristic
new bleno.Characteristic({
value : 'hello!',
uuid : '6d79686561727473656e74696e656c11',
properties : ['read'],
// Send a message back to the client with the characteristic's value
onReadRequest : function(offset, callback) {
console.log("Read request received");
callback(this.RESULT_SUCCESS, new Buffer("Echo: " + this.value);
}
})
]
}),
]);
}
});
HCI 数据包日志
连接成功时
Bluetooth monitor ver 5.50
= Note: Linux version 4.19.57-v7l+ (armv7l) 0.501891
= Note: Bluetooth subsystem version 2.22 0.501900
= New Index: xx:xx:xx:xx:xx:xx (Primary,UART,hci0) [hci0] 0.501905
= Open Index: xx:xx:xx:xx:xx:xx [hci0] 0.501908
= Index Info: xx:xx:xx:xx:xx:xx (Cypress Semiconductor Corporation) [hci0] 0.501911
@ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.501915
@ MGMT Open: btmon (privileged) version 1.14 {0x0002} 0.501989
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #1 [hci0] 4.586280
Type: Passive (0x00)
Interval: 60.000 msec (0x0060)
Window: 30.000 msec (0x0030)
Own address type: Public (0x00)
Filter policy: Ignore not in white list (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #2 [hci0] 4.586656
LE Set Scan Parameters (0x08|0x000b) ncmd 1
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #3 [hci0] 4.586717
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #4 [hci0] 4.587132
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 33 #5 [hci0] 4.619942
LE Advertising Report (0x02)
Num reports: 1
Event type: Connectable undirected - ADV_IND (0x00)
Address type: Public (0x00)
Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
RSSI: -31 dBm (0xe1)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #6 [hci0] 4.620014
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 #7 [hci0] 4.621661
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection (0x08|0x000d) plen 25 #8 [hci0] 4.621724
Scan interval: 60.000 msec (0x0060)
Scan window: 60.000 msec (0x0060)
Filter policy: White list is not used (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Own address type: Public (0x00)
Min connection interval: 30.00 msec (0x0018)
Max connection interval: 50.00 msec (0x0028)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Min connection length: 0.000 msec (0x0000)
Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4 #9 [hci0] 4.622251
LE Create Connection (0x08|0x000d) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 19 #10 [hci0] 4.726113
LE Connection Complete (0x01)
Status: Success (0x00)
Handle: 64
Role: Master (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Connection interval: 48.75 msec (0x0027)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Master clock accuracy: 0x00
@ MGMT Event: Device Connected (0x000b) plen 34 {0x0002} [hci0] 4.726162
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Flags: 0x00000000
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
@ MGMT Event: Device Connected (0x000b) plen 34 {0x0001} [hci0] 4.726162
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Flags: 0x00000000
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
< HCI Command: LE Read Remote Used Features (0x08|0x0016) plen 2 #11 [hci0] 4.726356
Handle: 64
> HCI Event: Command Status (0x0f) plen 4 #12 [hci0] 4.726943
LE Read Remote Used Features (0x08|0x0016) ncmd 1
Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 14 #13 [hci0] 4.726951
LE Read Remote Used Features (0x08|0x0016) ncmd 1
Status: Success (0x00)
00 00 00 00 00 00 00 00 00 00 ..........
> HCI Event: LE Meta Event (0x3e) plen 12 #14 [hci0] 4.881359
LE Read Remote Used Features (0x04)
Status: Success (0x00)
Handle: 64
Features: 0x3f 0x00 0x00 0x00 0x00 0x00 0x00 0x00
LE Encryption
Connection Parameter Request Procedure
Extended Reject Indication
Slave-initiated Features Exchange
LE Ping
LE Data Packet Length Extension
> HCI Event: LE Meta Event (0x3e) plen 11 #15 [hci0] 5.027630
LE Data Length Change (0x07)
Handle: 64
Max TX octets: 251
Max TX time: 2120
Max RX octets: 251
Max RX time: 2120
连接失败时
Bluetooth monitor ver 5.50
= Note: Linux version 4.19.57-v7l+ (armv7l) 0.114663
= Note: Bluetooth subsystem version 2.22 0.114671
= New Index: xx:xx:xx:xx:xx:xx (Primary,UART,hci0) [hci0] 0.114675
= Open Index: xx:xx:xx:xx:xx:xx [hci0] 0.114678
= Index Info: xx:xx:xx:xx:xx:xx (Cypress Semiconductor Corporation) [hci0] 0.114681
@ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.114686
@ MGMT Open: btmon (privileged) version 1.14 {0x0002} 0.114760
< HCI Command: Disconnect (0x01|0x0006) plen 3 #1 [hci0] 5.864108
Handle: 64
Reason: Remote User Terminated Connection (0x13)
> HCI Event: Command Status (0x0f) plen 4 #2 [hci0] 5.864469
Disconnect (0x01|0x0006) ncmd 1
Status: Success (0x00)
> HCI Event: Disconnect Complete (0x05) plen 4 #3 [hci0] 5.883803
Status: Success (0x00)
Handle: 64
Reason: Remote User Terminated Connection (0x13)
@ MGMT Event: Device Disconnected (0x000c) plen 8 {0x0002} [hci0] 5.883848
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Reason: Connection terminated by remote host (0x03)
@ MGMT Event: Device Disconnected (0x000c) plen 8 {0x0001} [hci0] 5.883848
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Reason: Connection terminated by remote host (0x03)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #4 [hci0] 25.059876
Type: Passive (0x00)
Interval: 60.000 msec (0x0060)
Window: 30.000 msec (0x0030)
Own address type: Public (0x00)
Filter policy: Ignore not in white list (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #5 [hci0] 25.060698
LE Set Scan Parameters (0x08|0x000b) ncmd 1
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #6 [hci0] 25.060762
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #7 [hci0] 25.061665
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 33 #8 [hci0] 39.473657
LE Advertising Report (0x02)
Num reports: 1
Event type: Connectable undirected - ADV_IND (0x00)
Address type: Public (0x00)
Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
RSSI: -28 dBm (0xe4)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #9 [hci0] 39.473746
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 #10 [hci0] 39.475900
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection (0x08|0x000d) plen 25 #11 [hci0] 39.475956
Scan interval: 60.000 msec (0x0060)
Scan window: 60.000 msec (0x0060)
Filter policy: White list is not used (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Own address type: Public (0x00)
Min connection interval: 30.00 msec (0x0018)
Max connection interval: 50.00 msec (0x0028)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Min connection length: 0.000 msec (0x0000)
Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4 #12 [hci0] 39.476993
LE Create Connection (0x08|0x000d) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection Cancel (0x08|0x000e) plen 0 #13 [hci0] 43.544123
> HCI Event: Command Complete (0x0e) plen 4 #14 [hci0] 43.546763
LE Create Connection Cancel (0x08|0x000e) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 19 #15 [hci0] 43.546914
LE Connection Complete (0x01)
Status: Unknown Connection Identifier (0x02)
Handle: 64
Role: Master (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Connection interval: 48.75 msec (0x0027)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Master clock accuracy: 0x00
失败时，gatttool输出错误为Error: connect error: Transport endpoint is not connected (107)
4000 ms 是一个相当大的广告间隔。无论如何，bluepy 使用 BlueZ，当 BlueZ 连接时，它首先扫描，当它找到想要的设备时，它停止扫描并发起连接。在此连接尝试期间，在再次开始扫描之前会超时。可能是这个 4000 毫秒的广告间隔大于超时。我认为通常是 2 秒。
请在尝试连接之前在您的中央设备上启动 "sudo btmon"，让它捕获并打印 HCI 数据包和 post 此处的输出。
广告间隔和连接间隔完全独立。
对于专业项目，我必须使用 RPI4 作为中央设备来连接到特定的外围设备。 为了进行测试，我开发了一个程序来模拟 RPi 上的外围设备（感谢 bleno Node.js 模块），方法是设置一个 GATT 服务器，并使用另一个 RPi 作为我的中心和 bluepy Python 库。
一切正常，但是当我在外围设备上将广告间隔设置为高于 4000 毫秒时，连接不再有效（即使在 RPi GATT 服务器或生产服务器上）。
我尝试在我的中心问题上使用 gatttool/hcitool，它运行良好，但前提是广告间隔小于 4000 毫秒。 但是当我尝试使用我的 phone 和专用应用程序（nRF 连接）连接到我的 GATT 服务器时它起作用了。
经过一番研究，我发现Linux内核只验证7.5ms - 4000ms（https://lkml.org/lkml/2019/8/2/358）范围内的连接间隔值，这与我的实验值完全吻合。但是除非我对 BLE 不了解，否则连接间隔和广告间隔是完全独立的，这应该不是问题。在蓝牙文档中，我发现最大广告间隔值应该是 10240ms。有点不明白
这是我的 GATT 服务器 运行 在一个 RPi4 上，如果你想重现的话。
我使用 sudo BLENO_ADVERTISING_INTERVAL=xxxx node my_gatt_server.js 开始它，xxxx 是我想要的以毫秒为单位的广告间隔。
var bleno = require('bleno');
// Once bleno starts, begin advertising our BLE address
bleno.on('stateChange', function(state) {
console.log('State change: ' + state);
if (state === 'poweredOn') {
bleno.startAdvertising('MyDevice',['6d79686561727473656e74696e656c10']);
} else {
bleno.stopAdvertising();
}
});
// Notify the console that we've accepted a connection
bleno.on('accept', function(clientAddress) {
console.log("Accepted connection from address: " + clientAddress);
});
// Notify the console that we have disconnected from a client
bleno.on('disconnect', function(clientAddress) {
console.log("Disconnected from address: " + clientAddress);
});
// When we begin advertising, create a new service and characteristic
bleno.on('advertisingStart', function(error) {
if (error) {
console.log("Advertising start error: " + error);
} else {
console.log("Advertising start success");
bleno.setServices([
// Define a new service
new bleno.PrimaryService({
uuid : '6d79686561727473656e74696e656c10',
characteristics : [
// ECG characteristic
new bleno.Characteristic({
value : 'hello!',
uuid : '6d79686561727473656e74696e656c11',
properties : ['read'],
// Send a message back to the client with the characteristic's value
onReadRequest : function(offset, callback) {
console.log("Read request received");
callback(this.RESULT_SUCCESS, new Buffer("Echo: " + this.value);
}
})
]
}),
]);
}
});
HCI 数据包日志
连接成功时
Bluetooth monitor ver 5.50
= Note: Linux version 4.19.57-v7l+ (armv7l) 0.501891
= Note: Bluetooth subsystem version 2.22 0.501900
= New Index: xx:xx:xx:xx:xx:xx (Primary,UART,hci0) [hci0] 0.501905
= Open Index: xx:xx:xx:xx:xx:xx [hci0] 0.501908
= Index Info: xx:xx:xx:xx:xx:xx (Cypress Semiconductor Corporation) [hci0] 0.501911
@ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.501915
@ MGMT Open: btmon (privileged) version 1.14 {0x0002} 0.501989
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #1 [hci0] 4.586280
Type: Passive (0x00)
Interval: 60.000 msec (0x0060)
Window: 30.000 msec (0x0030)
Own address type: Public (0x00)
Filter policy: Ignore not in white list (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #2 [hci0] 4.586656
LE Set Scan Parameters (0x08|0x000b) ncmd 1
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #3 [hci0] 4.586717
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #4 [hci0] 4.587132
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 33 #5 [hci0] 4.619942
LE Advertising Report (0x02)
Num reports: 1
Event type: Connectable undirected - ADV_IND (0x00)
Address type: Public (0x00)
Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
RSSI: -31 dBm (0xe1)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #6 [hci0] 4.620014
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 #7 [hci0] 4.621661
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection (0x08|0x000d) plen 25 #8 [hci0] 4.621724
Scan interval: 60.000 msec (0x0060)
Scan window: 60.000 msec (0x0060)
Filter policy: White list is not used (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Own address type: Public (0x00)
Min connection interval: 30.00 msec (0x0018)
Max connection interval: 50.00 msec (0x0028)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Min connection length: 0.000 msec (0x0000)
Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4 #9 [hci0] 4.622251
LE Create Connection (0x08|0x000d) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 19 #10 [hci0] 4.726113
LE Connection Complete (0x01)
Status: Success (0x00)
Handle: 64
Role: Master (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Connection interval: 48.75 msec (0x0027)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Master clock accuracy: 0x00
@ MGMT Event: Device Connected (0x000b) plen 34 {0x0002} [hci0] 4.726162
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Flags: 0x00000000
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
@ MGMT Event: Device Connected (0x000b) plen 34 {0x0001} [hci0] 4.726162
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Flags: 0x00000000
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
< HCI Command: LE Read Remote Used Features (0x08|0x0016) plen 2 #11 [hci0] 4.726356
Handle: 64
> HCI Event: Command Status (0x0f) plen 4 #12 [hci0] 4.726943
LE Read Remote Used Features (0x08|0x0016) ncmd 1
Status: Success (0x00)
> HCI Event: Command Complete (0x0e) plen 14 #13 [hci0] 4.726951
LE Read Remote Used Features (0x08|0x0016) ncmd 1
Status: Success (0x00)
00 00 00 00 00 00 00 00 00 00 ..........
> HCI Event: LE Meta Event (0x3e) plen 12 #14 [hci0] 4.881359
LE Read Remote Used Features (0x04)
Status: Success (0x00)
Handle: 64
Features: 0x3f 0x00 0x00 0x00 0x00 0x00 0x00 0x00
LE Encryption
Connection Parameter Request Procedure
Extended Reject Indication
Slave-initiated Features Exchange
LE Ping
LE Data Packet Length Extension
> HCI Event: LE Meta Event (0x3e) plen 11 #15 [hci0] 5.027630
LE Data Length Change (0x07)
Handle: 64
Max TX octets: 251
Max TX time: 2120
Max RX octets: 251
Max RX time: 2120
连接失败时
Bluetooth monitor ver 5.50
= Note: Linux version 4.19.57-v7l+ (armv7l) 0.114663
= Note: Bluetooth subsystem version 2.22 0.114671
= New Index: xx:xx:xx:xx:xx:xx (Primary,UART,hci0) [hci0] 0.114675
= Open Index: xx:xx:xx:xx:xx:xx [hci0] 0.114678
= Index Info: xx:xx:xx:xx:xx:xx (Cypress Semiconductor Corporation) [hci0] 0.114681
@ MGMT Open: bluetoothd (privileged) version 1.14 {0x0001} 0.114686
@ MGMT Open: btmon (privileged) version 1.14 {0x0002} 0.114760
< HCI Command: Disconnect (0x01|0x0006) plen 3 #1 [hci0] 5.864108
Handle: 64
Reason: Remote User Terminated Connection (0x13)
> HCI Event: Command Status (0x0f) plen 4 #2 [hci0] 5.864469
Disconnect (0x01|0x0006) ncmd 1
Status: Success (0x00)
> HCI Event: Disconnect Complete (0x05) plen 4 #3 [hci0] 5.883803
Status: Success (0x00)
Handle: 64
Reason: Remote User Terminated Connection (0x13)
@ MGMT Event: Device Disconnected (0x000c) plen 8 {0x0002} [hci0] 5.883848
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Reason: Connection terminated by remote host (0x03)
@ MGMT Event: Device Disconnected (0x000c) plen 8 {0x0001} [hci0] 5.883848
LE Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Reason: Connection terminated by remote host (0x03)
< HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 #4 [hci0] 25.059876
Type: Passive (0x00)
Interval: 60.000 msec (0x0060)
Window: 30.000 msec (0x0030)
Own address type: Public (0x00)
Filter policy: Ignore not in white list (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #5 [hci0] 25.060698
LE Set Scan Parameters (0x08|0x000b) ncmd 1
Status: Success (0x00)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #6 [hci0] 25.060762
Scanning: Enabled (0x01)
Filter duplicates: Enabled (0x01)
> HCI Event: Command Complete (0x0e) plen 4 #7 [hci0] 25.061665
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 33 #8 [hci0] 39.473657
LE Advertising Report (0x02)
Num reports: 1
Event type: Connectable undirected - ADV_IND (0x00)
Address type: Public (0x00)
Address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Data length: 21
Flags: 0x06
LE General Discoverable Mode
BR/EDR Not Supported
128-bit Service UUIDs (partial): 1 entry
Vendor specific (6d796865-6172-7473-656e-74696e656c10)
RSSI: -28 dBm (0xe4)
< HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 #9 [hci0] 39.473746
Scanning: Disabled (0x00)
Filter duplicates: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 4 #10 [hci0] 39.475900
LE Set Scan Enable (0x08|0x000c) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection (0x08|0x000d) plen 25 #11 [hci0] 39.475956
Scan interval: 60.000 msec (0x0060)
Scan window: 60.000 msec (0x0060)
Filter policy: White list is not used (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Own address type: Public (0x00)
Min connection interval: 30.00 msec (0x0018)
Max connection interval: 50.00 msec (0x0028)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Min connection length: 0.000 msec (0x0000)
Max connection length: 0.000 msec (0x0000)
> HCI Event: Command Status (0x0f) plen 4 #12 [hci0] 39.476993
LE Create Connection (0x08|0x000d) ncmd 1
Status: Success (0x00)
< HCI Command: LE Create Connection Cancel (0x08|0x000e) plen 0 #13 [hci0] 43.544123
> HCI Event: Command Complete (0x0e) plen 4 #14 [hci0] 43.546763
LE Create Connection Cancel (0x08|0x000e) ncmd 1
Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 19 #15 [hci0] 43.546914
LE Connection Complete (0x01)
Status: Unknown Connection Identifier (0x02)
Handle: 64
Role: Master (0x00)
Peer address type: Public (0x00)
Peer address: xx:xx:xx:xx:xx:xx (OUI DC-A6-32)
Connection interval: 48.75 msec (0x0027)
Connection latency: 0 (0x0000)
Supervision timeout: 420 msec (0x002a)
Master clock accuracy: 0x00
失败时，gatttool输出错误为Error: connect error: Transport endpoint is not connected (107)
4000 ms 是一个相当大的广告间隔。无论如何，bluepy 使用 BlueZ，当 BlueZ 连接时，它首先扫描，当它找到想要的设备时，它停止扫描并发起连接。在此连接尝试期间，在再次开始扫描之前会超时。可能是这个 4000 毫秒的广告间隔大于超时。我认为通常是 2 秒。
请在尝试连接之前在您的中央设备上启动 "sudo btmon"，让它捕获并打印 HCI 数据包和 post 此处的输出。
广告间隔和连接间隔完全独立。