BLECharacteristic::subscribe() fails with iTag

[gdsports]

My BLE central iTag program based on the SensorTag example fails at the simpleKeyCharacteristic.subscribe() step. I "fixed" the problem as shown below. The characteristics properties are not available at this point but I assume the correct way to handle this is to check for BLEWrite versus BLEWriteWithoutResponse. Without this change the subscribe() blocks for a few seconds then returns an error.

int BLERemoteDescriptor::writeValue

#if 0
  uint8_t resp[4];
  int respLength = ATT.writeReq(_connectionHandle, _handle, value, length, resp);

  if (!respLength) {
    return 0;
  }

  if (resp[0] == 0x01) {
    // error
    return 0;
  }

#else
  ATT.writeCmd(_connectionHandle, _handle, value, length);
#endif

[sandeepmistry]

Hi @gdsports,

Do you think you could provide some debug logging for this. Please add BLE.debug(Serial); in the setup() of your sketch and provide the output of the Serial Monitor. Thanks.

[gdsports]

Ok, here is the log without code changes.

12:45:57.333 -> HCI EVENT RX <- 043E1A0201000039080B00FFFF0E020105020A000319C1030302E0FFB4
12:45:57.399 -> HCI EVENT RX <- 043E1E0201040039080B00FFFF12110969544147202020202020202020202020BE
12:45:57.465 -> Discovered a peripheral
12:45:57.465 -> -----------------------
12:45:57.465 -> Address: ff:ff:00:xx:yy:zz
12:45:57.465 -> Local Name: [iTAG            ]
12:45:57.465 -> Service UUIDs: ffe0 
12:45:57.465 -> RSSI: -66
12:45:57.465 -> 
12:45:57.465 -> HCI COMMAND TX -> 010C20020000
12:45:57.498 -> HCI EVENT RX <- 040E04010C2000
12:45:57.532 -> Found iTag
12:45:57.532 -> Connecting ...
12:45:57.532 -> HCI COMMAND TX -> 010D201960003000000039080B00FFFF0006000C000000C80004000600
12:45:57.598 -> HCI EVENT RX <- 040F0400010D20
12:45:57.730 -> HCI EVENT RX <- 043E1301000000000039080B00FFFF08000000C80007
12:45:57.764 -> Connected ff:ff:00:xx:yy:zz 
12:45:57.764 -> Connected
12:45:57.764 -> Discovering service 0xffe0 ...
12:45:57.797 -> HCI ACLDATA TX -> 02000007000300040002F700
12:45:57.947 -> HCI EVENT RX <- 0413050100000100
12:45:57.947 -> HCI ACLDATA RX <- 020020070003000400031700
12:45:57.947 -> HCI ACLDATA TX -> 0200000B0007000400100100FFFF0028
12:45:57.947 -> HCI EVENT RX <- 0413050100000100
12:45:57.947 -> HCI ACLDATA RX <- 0200201800140004001106010005000018060008000F1809000B000218
12:45:57.947 -> HCI ACLDATA TX -> 0200000B0007000400100C00FFFF0028
12:45:57.947 -> HCI EVENT RX <- 0413050100000100
12:45:57.996 -> HCI ACLDATA RX <- 0200200C000800040011060C000E00E0FF
12:45:58.029 -> HCI ACLDATA TX -> 0200000B0007000400100F00FFFF0028
12:45:58.095 -> HCI EVENT RX <- 0413050100000100
12:45:58.128 -> HCI ACLDATA RX <- 02002009000500040001100F000A
12:45:58.128 -> HCI ACLDATA TX -> 0200000B0007000400080C000E000328
12:45:58.194 -> HCI EVENT RX <- 0413050100000100
12:45:58.194 -> HCI ACLDATA RX <- 0200200D000900040009070D00120E00E1FF
12:45:58.261 -> HCI ACLDATA TX -> 0200000B0007000400080F000E000328
12:45:58.294 -> HCI EVENT RX <- 0413050100000100
12:45:58.327 -> HCI ACLDATA RX <- 02002009000500040001080F000A
12:45:58.327 -> Service discovered
12:45:58.360 -> Subscribing to simple key characteristic ...
12:45:58.360 -> HCI ACLDATA TX -> 020000090005000400120F000100
12:45:58.393 -> HCI EVENT RX <- 0413050100000100
12:46:03.361 -> subscription failed!
12:46:03.394 -> HCI COMMAND TX -> 01060403000013
12:46:03.427 -> HCI EVENT RX <- 040F0400010604
12:46:03.427 -> HCI EVENT RX <- 04050400000016
12:46:03.461 -> Disconnected ff:ff:00:xx:yy:zz 
12:46:03.461 -> HCI COMMAND TX -> 010C20020001
12:46:03.461 -> HCI EVENT RX <- 040E04010C2000
12:46:03.494 -> HCI COMMAND TX -> 010B200701100010000000
12:46:03.527 -> HCI EVENT RX <- 040E04010B2000
12:46:03.527 -> HCI COMMAND TX -> 010C20020101
12:46:03.560 -> HCI EVENT RX <- 040E04010C2000
12:46:03.560 -> HCI COMMAND TX -> 010A200101
12:46:03.593 -> HCI EVENT RX <- 040E04010A2000
12:46:04.388 -> HCI COMMAND TX -> 010C20020001
12:46:04.421 -> HCI EVENT RX <- 040E04010C2000
12:46:04.454 -> HCI COMMAND TX -> 010B200701100010000000
12:46:04.487 -> HCI EVENT RX <- 040E04010B2000
12:46:04.521 -> HCI COMMAND TX -> 010C20020101
12:46:04.521 -> HCI EVENT RX <- 040E04010C2000

[sandeepmistry]

Thanks @gdsports,

Have you tested the peripheral with other centrals like iOS or Android? Do they work when subscribing?

It seems macOS and iOS will send a write request as this library does.

[gdsports]

gatttool running on a raspberry pi works with the iTag. And light blue on IOS.

[gdsports]

I got an old SensorTag based on the CC2541 working with a small change to the
SensorTag example sketch. The localName is slightly different. Works fine without
changing BLERemoteDescriptor::writeValue.

--- a/examples/Central/SensorTagButton/SensorTagButton.ino
+++ b/examples/Central/SensorTagButton/SensorTagButton.ino
@@ -51,7 +51,10 @@ void loop() {
 
     // Check if the peripheral is a SensorTag, the local name will be:
     // "CC2650 SensorTag"
-    if (peripheral.localName() == "CC2650 SensorTag") {
+    // For very old SensorTags based on the CC2541, the local name will be
+    // "SensorTag"
+    String local_name = peripheral.localName();
+    if ((local_name == "CC2650 SensorTag") || (local_name == "SensorTag")) {
       // stop scanning
       BLE.stopScan();

[mockendon]

Found this bug report while trying to understand why the only thing I can get to accept a .subscribe request is a very old devkit TI keyfob. That works perfectly but nothing else (physical or virtual) will accept a request to subscribe using the arduinoBLE library on my Nano 33 IoT.

gsports 'fix' for int BLERemoteDescriptor::writeValue (I'm assuming is to be added to BLERemoteCharacteristic.cpp) is a great idea but didn't help me.

Is there an authentication problem in the library?

[sandeepmistry]

Is there an authentication problem in the library?

@mockendon Currently authentication is not supported in this library. #36 is open to track that feature.

[mockendon]

Thank you sandeepmistry! I had assumed the authentication that was missing was for pin codes and encryption. It all becomes clear!

[Jamal-Nazzal]

has this been solved ever?