ESP32 Technical Tutorials: BLE Notifications

[@axa.axa.]

12:50 Neil doesn't monitor this project anymore, but others should know he got the notification and indication definitions backwards. Its a Indication that requires a response, while a Notification doesn't

[@fabioricardodeoliveira9451]

Hello Mr Kolban, this is a wonderful class...

[@RaadYacu]

Very Informative Kolban - need to put this info to use. I have to say, this is the most detailed about BT I have seen so far

[@kolbantechnicaltutorials4715]

Thanks Raad. I'm still walking the learning path for BLE myself so my posts and videos should always have the disclaimer "... To the best of my knowledge" and I welcome questions as those cause me to query my own models as well as guide on where I should study and try and assist others. I recommend the ESP32 forum for posting questions on BLE in general. That way as many folks as possible might benefit and chime in with thinking. See esp32.com/index.php.

[@RaadYacu]

Got your book also. You will mentoring me without knowing it. Again - great job

[@RaadYacu]

Neil I was reading your book and it referred to the iTAG as a BLE to test against with ESP acting as the master and the iTAG as a peripheral However, for the life of me I cannot get the service to notify me when a button is pressed. Am I missing something? I am able to connect to the device from esp32 but thats about it. Is that not the 0xffe0 service ?

[@MURATSPLAT]

Hello from Turkey @kolban it is great stuff for understanding a BLA device and ESP32 communication..

[@koz]

Excellent clear explanation. Thank you!

[@Set1ish]

Great video and speak! Very crystal exposition.

[@SkyRiderJavelin]

Excellent video well presented clear and understandable , thanks very much

[@juergenwickenhaeuser3329]

Thanks for your very good explanation!

[@olaniyioluseun8250]

Thank you so much for this comprehensive tutorial. Almost 2 years made available and still very relevant. Have carefully used your steps but I will like to know how to read temperature data via a simple python code on raspberry-pi. Pardon my ignorance, I am entirely new to python, and I've been using it for a project which the ESP32 has become useful and with your explanatory tutorial, much more resourceful. Thanks.

[@Olfox2]

Great tutorial Kolban... as usual :) . I want to test now !

[@michaellin6696]

nice tutorial, thanks heaps.

[@siowlimchow7755]

Very well explained.

[@larsfagerbakke2140]

Very useful, thanks!

[@justdoingodswork]

Great tutorial helped me clear lots of thing regarding BLE. But Still I need help with to know how to disconnect client from server after certain counter value. Then starts new service with different UUID & Characteristics. For connection of new client.

[@frankji2410]

very nice

[@iiilllii140]

Could you link the video to the c++ classes that encapsulate those BLE functions, you mentioned, I can't find it.

[@ljay0778]

Wonderfull!

[@sdplusm3]

Dear Kolban, thank you for the nice video tutorial. At 13:02 you indicate that when the server performs a notification it will receive an ACKnowledge when the server performs an Indication, it is fire and forget. Shouldn't it be reversed? I mean notification is fire and forget, Indication requires an ACKnowledge. Thank you.

[@axa.axa.]

youre right

[@marcotulio-analogchannel306]

Hello Kolban!!! Thanks for sharing!!! is it possible to connect two esp32 with BLE (one as a server an another as a client) ? how to do it?

[@vishnunaikdhanavath]

Hi, Kolban thanks for your clear explanation. I am having a doubt If the client(Sensor) has to send data to the server(ESP32) over Bluetooth what are the changes I need to do in the above code?

[@adiqal697]

Respect, thank you for your valuable tips. I am asking for advice, I am building an application based on ESP32C3 Supermini which is to collect pressure samples and remember them. The entire program is already working. When someone connects via Bluetooth with a phone (as a server client) - ESP32 is to send them all the saved pressure samples as a packet of 2000 16-bit samples. I am creating an application for the phone in the APP Inventor environment. Could you suggest how to organize the sending of a measurement packet from ESP32 to the phone on a request sent from it? Thank you very much! Greetings from Poland :)

[@diegosantosinsua]

ehhhh, it is great !!! thk a loat !! please conitune put more videos men !!

[@piotrolczyk2679]

Do you have any example of communication between a BLE server and a BLE client in INDICATE characteristic mode. Any hint?

[@omarcampos6520]

hi :) can u help me? how can i disconnect bluetooth after 5 second?

Thanks for great tutorial. What is this phone emulator?

[@sanshotur]

vysor

[@kolbantechnicaltutorials4715]

As Alexander says, the software I am using is Vysor but it isn't an emulator. Its the ability to visually expose my Android phone onto my Windows 10 PC desktop. Gives me keyboard and mouse without me having to peer over my phone.

[@Turbo_Tastic]

The Android app he is using is called nRF Connect for Mobile

[@swapniilkanwar8598]

Sir can you please clarify the 'notification' and 'indication' definition. On various websites it is said that indicate needs acknowledgement and notify doesn't. This is creating a problem in an experiment I am conducting.

[@MoodersInit]

brilliant :D

[@xyber2]

Hi, great videos, I learned a lot, thanks! I'm thinking on using ESP32 in my engineering thesis on WSN bluetooth network. Would You consider covering also programming ESP32 as client, and communicating 2 ESP32's with each other using BLE? That would be great!

[@kolbantechnicaltutorials4715]

Howdy and thanks for the kind words. My immediate thinking is that since we have got videos for using an ESP32 as a server and a second video for using ESP32 as a client, the idea of using two ESP32s to talk to each other should just "fall out" from using them in that fashion. Let me suggest you might have a go and then if you have issues, you can post the questions/comments to this forum thread ... esp32.com/viewtopic.php?f=13&t=2330

[@Fantonrko]

I dont know why, but BLE taking 70-110 mA in works, how i can decrease value ?

[@matthewhenderson4690]

I get a ton of red error messages from this code and it doesn't compile :(

[@tinkerk6019]

Hello Kolban Thanks for this great tutorial. I am doing one project in which I need to transfer an audio file from our mobile phone to esp32 via bluetooth, please provide some sort of guidance for it.

[@gudimetlakowshik3617]

Hey kolban.....That's really very nice work...Thanks....I have a small issue....I established a connection between server and client successfully and I am able to send the data successfully. But, I want a small change here. I will be manually writing the data to the server using a mobile application and I want to transmitt the same data to the client over BLE. Is this possible?? Please help me out..

[@InfoRoboteaK]

Hi! Thanks for the video! I have an issue. I'm using Arduino IDE and I don't know how to get the device UUID of the ESP32. Do you have an idea? I need it for show it on a QR code and connect it from an iOS app. Thanks!

[@FLBRGZ]

Hello, you are a very smart person, one who likes a challenge?. I have a problem. I want to connect to Zwift cycling program as ble ftms and receive gradient or resistance data, I want to build my own smart indoor trainer. I can connect as heart rate, speed and cadence with my esp32 but not as fitness machine. Any ideas? Anyway I will check out your other videos. Regards Paul.

[@Usuaurio-kj1ym]

Hello thanks, can you helpme im try to do with HM-10 BLE module

[@AgilityJumps]

Hi Kolban, very interesting thank you, can you post a link to the sample code?

[@AgilityJumps]

Sorry i found it .... thank you :-) github.com/nkolban/esp32-snippets/tree/master/cpp_utils/tests/BLE%20Tests

[@AgilityJumps]

Hi Kolban i try to load into my ESP32 your sample code, but i bekome errors: C:/esp/BLE_Test/components/cpp_utils/BLEDescriptor.cpp: In member function 'void BLEDescriptor::executeCreate(BLECharacteristic*)': C:/esp/BLE_Test/components/cpp_utils/BLEDescriptor.cpp:67:12: error: invalid conversion from 'int' to 'esp_gatt_perm_t' [-fpermissive] &control); ^ In file included from C:/esp/BLE_Test/components/cpp_utils/BLEService.h:13:0, from C:/esp/BLE_Test/components/cpp_utils/BLEDescriptor.cpp:16: C:/msys32/home/user/esp/esp-idf/components/bt/bluedroid/api/include/esp_gatts_api.h:393:11: note: initializing argument 3 of 'esp_err_t esp_ble_gatts_add_char_descr(uint16_t, esp_bt_uuid_t*, esp_gatt_perm_t, esp_attr_value_t*, esp_attr_control_t*)' esp_err_t esp_ble_gatts_add_char_descr (uint16_t service_handle, ^ make[1]: *** [/home/user/esp/esp-idf/make/component_wrapper.mk:177: BLEDescriptor.o] Error 1 make: *** [C:/msys32/home/user/esp/esp-idf/make/project.mk:386: cpp_utils-build] Error 2 I make flash.... Can you check ? Thankyou....

[@kolbantechnicaltutorials4715]

howdy ... post to this thread ... esp32.com/viewtopic.php?f=13&t=2330 the puzzle or ping me on IRC in ESP32 channel. ... We'll get you going.

[@kolbantechnicaltutorials4715]

I just did a clean build with no issues ... however, that doesn't mean that what was on Github didn't contain some error so I just synched the best so far with Github right now as of this time.

[@AgilityJumps]

Thankyou i try now :-)

[@browaruspierogus2182]

What IDE and environment is it? How to set it up?

[@naasikhendricks1501]

Browarus Pierogus Eclipse, and IDF.

[@seigel]

Looks like CLion

[@siowlimchow7755]

Hi Kolban, Would you please share the Git link of the source? I tried to google it. However, i found github.com/nkolban?page=2&tab=repositories, but I could not find the BLE notifications source. Help please?

[@kolbantechnicaltutorials4715]

The samples can be found here ... github.com/nkolban/esp32-snippets/tree/master/cpp_utils/tests/BLETests I think this is where the source is likely to be found.

[@leonvilfand2192]

Excellent tutorial! Thanks. Question: BLE 5.0 support on newer ESP32 SoC means that in theory our BLE signal range should increase 4 times (compared to ESP SoC with BLE4.2, which should only be around 10m or so). But what is it in practice? Is there a real difference in BLE range between ESP32 SoC running BLE4.2 vs the newer ESP32 SoC running BLE5.0. ?

[@Menarafineart]

Hi thanks for the tutorials please can you refer me to a book. I am trying to adapt this technologie to my b2b saas any help will be very welcome

[@akshaypohankar3784]

hi, thank you for all these interesting videos. I want to ask for a small help "I want to use BLE to communicate with a smartphone app i am using Sparkfun esp 32 things and Arduino for programming " can you point me to a suitable code or tutorials. thank you all in advance

[@kolbantechnicaltutorials4715]

It might be that Blynk is what you need ... www.blynk.cc/ For the ESP32, have a look at this thread. esp32.com/viewtopic.php?f=13&t=2330

[@akshaypohankar3784]

no we can not use blynk one of my team members is making Android app he just want me a way communicate with SparkFun esp 32 things using Bluetooth a lot of other parts of this project are programmed in Arduino hence Arduino is preferred

[@akshaypohankar3784]

hi thanks for all the help you are doing today i found your esp 32 ble Arduino library in library manager so i dawnloaded to my arduino 1.6 and tryed to run it in my esp32(wroom 32 dev kit ) but it gave me fallowing error C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp: In static member function 'static std::__cxx11::string BLEUtils::gattClientEventTypeToString(esp_gattc_cb_event_t)': C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:344:8: error: 'ESP_GATTC_CONNECT_EVT' was not declared in this scope case ESP_GATTC_CONNECT_EVT: ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:346:8: error: 'ESP_GATTC_DISCONNECT_EVT' was not declared in this scope case ESP_GATTC_DISCONNECT_EVT: ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp: In static member function 'static void BLEUtils::dumpGattClientEvent(esp_gattc_cb_event_t, esp_gatt_if_t, esp_ble_gattc_cb_param_t*)': C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:684:8: error: 'ESP_GATTC_CONNECT_EVT' was not declared in this scope case ESP_GATTC_CONNECT_EVT: { ^ In file included from C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:22:0: C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:686:44: error: 'union esp_ble_gattc_cb_param_t' has no member named 'connect' BLEUtils::gattStatusToString(evtParam->connect.status).c_str(), ^ C:\Users\Akshay\Documents\Arduino\hardware\espressif\esp32/tools/sdk/include/log/esp_log.h:144:168: note: in definition of macro 'ESP_LOGD' #define ESP_LOGD( tag, format, ... ) if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) { esp_log_write(ESP_LOG_DEBUG, tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:687:15: error: 'union esp_ble_gattc_cb_param_t' has no member named 'connect' evtParam->connect.conn_id, ^ C:\Users\Akshay\Documents\Arduino\hardware\espressif\esp32/tools/sdk/include/log/esp_log.h:144:168: note: in definition of macro 'ESP_LOGD' #define ESP_LOGD( tag, format, ... ) if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) { esp_log_write(ESP_LOG_DEBUG, tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:688:26: error: 'union esp_ble_gattc_cb_param_t' has no member named 'connect' BLEAddress(evtParam->connect.remote_bda).toString().c_str() ^ C:\Users\Akshay\Documents\Arduino\hardware\espressif\esp32/tools/sdk/include/log/esp_log.h:144:168: note: in definition of macro 'ESP_LOGD' #define ESP_LOGD( tag, format, ... ) if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) { esp_log_write(ESP_LOG_DEBUG, tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:700:8: error: 'ESP_GATTC_DISCONNECT_EVT' was not declared in this scope case ESP_GATTC_DISCONNECT_EVT: { ^ In file included from C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:22:0: C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:702:44: error: 'union esp_ble_gattc_cb_param_t' has no member named 'disconnect' BLEUtils::gattStatusToString(evtParam->disconnect.status).c_str(), ^ C:\Users\Akshay\Documents\Arduino\hardware\espressif\esp32/tools/sdk/include/log/esp_log.h:144:168: note: in definition of macro 'ESP_LOGD' #define ESP_LOGD( tag, format, ... ) if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) { esp_log_write(ESP_LOG_DEBUG, tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:703:15: error: 'union esp_ble_gattc_cb_param_t' has no member named 'disconnect' evtParam->disconnect.conn_id, ^ C:\Users\Akshay\Documents\Arduino\hardware\espressif\esp32/tools/sdk/include/log/esp_log.h:144:168: note: in definition of macro 'ESP_LOGD' #define ESP_LOGD( tag, format, ... ) if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) { esp_log_write(ESP_LOG_DEBUG, tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } ^ C:\Users\Akshay\Documents\Arduino\libraries\ESP32_BLE_Arduino\src\BLEUtils.cpp:704:26: error: 'union esp_ble_gattc_cb_param_t' has no member named 'disconnect' BLEAddress(evtParam->disconnect.remote_bda).toString().c_str() ^ C:\Users\Akshay\Documents\Arduino\hardware\espressif\esp32/tools/sdk/include/log/esp_log.h:144:168: note: in definition of macro 'ESP_LOGD' #define ESP_LOGD( tag, format, ... ) if (LOG_LOCAL_LEVEL >= ESP_LOG_DEBUG) { esp_log_write(ESP_LOG_DEBUG, tag, LOG_FORMAT(D, format), esp_log_timestamp(), tag, ##__VA_ARGS__); } ^ exit status 1 Error compiling for board ESP32 Dev Module. what have i done wrong any suggestions. i tried several options but all my other codes are complining and uploading except exampal codes from this library .

[@kolbantechnicaltutorials4715]

Howdy, Have a look at the following Github issue which I hope will explain the story.... github.com/nkolban/esp32-snippets/issues/59 If not, please feel free to create issues on this repository for resolution.

[@akshaypohankar3784]

a very nice and detailed explanation I did what you said removed my old esp 32 Arduino files and added new using git GUI and then tried your BLE_uart example it worked very well thank you i wish i could show you images

[@kolbantechnicaltutorials4715]

Ashkay ... the knowledge that it worked for you is thanks enough.

[@akshaypohankar3784]

sorry for disturbing you again but when I tried to use this library for Sparkfun things board it gave me following error i tried no of different things but the problem is not solved. the error message Rebooting... ets Jun 8 2016 00:22:57 rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT) configsip: 0, SPIWP:0xee clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00 mode:DIO, clock div:1 load:0x3fff0010,len:4 load:0x3fff0014,len:588 load:0x40078000,len:0 load:0x40078000,len:9880 entry 0x400789d8 abort() was called at PC 0x400d8cd3 on core 0 Backtrace: 0x4008832c:0x3ffdc360 0x4008842b:0x3ffdc380 0x400d8cd3:0x3ffdc3a0 0x400da342:0x3ffdc3c0 0x400da4ce:0x3ffdc3e0 0x400da819:0x3ffdc420 0x400da859:0x3ffdc450 0x400da869:0x3ffdc470 0x400d667e:0x3ffdc490 0x400d52f9:0x3ffdc4b0 0x400d410d:0x3ffdc4f0 0x400f340d:0x3ffdc510 0x400ef4b2:0x3ffdc550 Rebooting... ets Jun 8 2016 00:22:57 rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT) configsip: 0, SPIWP:0xee clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00 mode:DIO, clock div:1 load:0x3fff0010,len:4 load:0x3fff0014,len:588 load:0x40078000,len:0 load:0x40078000,len:9880 entry 0x400789d8 abort() was called at PC 0x400d8cd3 on core 0 Backtrace: 0x4008832c:0x3ffdc360 0x4008842b:0x3ffdc380 0x400d8cd3:0x3ffdc3a0 0x400da342:0x3ffdc3c0 0x400da4ce:0x3ffdc3e0 0x400da819:0x3ffdc420 0x400da859:0x3ffdc450 0x400da869:0x3ffdc470 0x400d667e:0x3ffdc490 0x400d52f9:0x3ffdc4b0 0x400d410d:0x3ffdc4f0 0x400f340d:0x3ffdc510 0x400ef4b2:0x3ffdc550 Rebooting...

[@kolban1]

Howdy, let me suggest you create an issue on the Github repository to try and debug problems. The repository can be found here: github.com/nkolban/esp32-snippets

[@JoeyBlade]

So much good stuff. For anyone looking for the SampleNotify.cpp file, as of this comment it is found here: github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLETests/

[@hikolanikola8775]

how the fck do we send data by notifications bidirectional...

[@kaz4mi]

Нифига не понятно, пж снимай на русском языке

[@unlokia]

Careful now, you're gonna have the girls falling *all over you* talking like this...

[@beypazariofficial]

i was expecting indian accent