googlecloudplatform / google-cloud-iot-arduino

Google Cloud IOT Example on ESP8266

Google Cloud IoT JWT

This is an example of how to generate JSON Web Token (JWT) credentials for connecting to Google Cloud IoT Core.

This contains two parts: a library to make a JWT (json web token) which is used to authenticate with Google Cloud IoT, and Arduino sketches that demonstrate how to connect to Google Cloud IoT using the available MQTT bridge.

This example is not an officially supported Google product, does not have a SLA/SLO, and should not be used in production.

Supported hardware targets

Currently, we support the following hardware targets:

• Genuino MKR1000 and WiFi1010
• Espressif ESP32
• Espressif ESP8266

Dependencies

Some examples use specific dependencies that need to be installed via the Arduino Library manager.

• lwMQTT

Quickstart

First, install the library using the Arduino Library Manager.

• Open Arduino and select the Sketch > Include Library > Library Manager menu item.
• In the filter box, search for "Google Cloud IoT JWT".
• Install the library

Next, enable the Cloud IoT Core API by opening the Google Cloud IoT Core console.

Next, create your device registry as described in the Quickstart or by using the Google Cloud SDK.

If you're using the SDK, the following commands will setup PubSub and Cloud IoT Core for testing on your Arduino device:

Create the PubSub topic and subscription:

gcloud pubsub topics create atest-pub --project=YOUR_PROJECT_ID
gcloud pubsub subscriptions create atest-sub --topic=atest-pub

Create the Cloud IoT Core registry:

gcloud iot registries create atest-registry \
  --region=us-central1 --event-notification-config=topic=atest-pub

Generate an Eliptic Curve (EC) private / public key pair:

openssl ecparam -genkey -name prime256v1 -noout -out ec_private.pem
openssl ec -in ec_private.pem -pubout -out ec_public.pem

Register the device using the keys you generated:

gcloud iot devices create atest-dev --region=us-central1 \
    --registry=atest-registry \
    --public-key path=ec_public.pem,type=es256

At this point, your registry is created and your device has been added to the registry so you're ready to connect it.

Select one of the available samples from the File > Examples > Google Cloud IoT Core JWT menu and find the configuration section (ciotc_config.h in newer examples).

Find and replace the following values first:

• Project ID (get from console or gcloud config list)
• Location (default is us-central1)
• Registry ID (created in previous steps, e.g. atest-reg)
• Device ID (created in previous steps, e.g. atest-device)

You will also need to extract your private key using the following command:

openssl ec -in ec_private.pem -noout -text

... and will need to copy the output for the private key bytes into the private key string in your Arduino project.

When you run the sample, the device will connect and receive configuration from Cloud IoT Core. When you change the configuration in the Cloud IoT Core console, that configuration will be reflrected on the device.

Before the examples will work, you will also need to configure the root certificate as described in the configuration headers.

After you have published telemetry data, you can read it from the PubSub topic using the Google Cloud SDK. With the SDK installed, run the following command to create a :

gcloud pubsub subscriptions create <your-subscription-name> --topic=<your-iot-pubsub-topic>

Then read the telemetry messages:

gcloud pubsub subscriptions pull --limit 500 --auto-ack <your-subscription-name>

Notes on the certificate

The root certificate from Google is used to verify communication to Google. Although unlikely, it's possible for the certificate to expire or rotate, requiring you to update it.

If you're using the ESP8266 project, you need to either install the Certificate to SPIFFS using the SPIFFS upload utility or will need to uncomment the certificate bytes in the sample. Note that the SPIFFS utility simply uploads the files stored in the data subfolder. The sample assumes the file is called ca.crt:

├── Esp8266...
│   ├── data
│   │   └── ca.crt

To convert the certificate to the DER format, the following command shuold be used:

wget pki.goog/roots.pem
openssl x509 -outform der -in roots.pem -out ca.crt

If you're using the ESP32, you can paste the certificate bytes (don't forget the \n characters) into the sample. You can use any of the root certificate bytes for the certificates with Google Trust Services (GTS) as the certificate authority (CA). This is easy to get using curl, e.g.

curl pki.goog/roots.pem

If you're using Genuino boards like the MKR1000, you will need to add SSL certificates to your board as described on Hackster.io. The MQTT server address is mqtt.googleapis.com and the port is either 8883 for most cases or 443 in case your device is running in an environment where port 8883 is blocked. For long-term support, the server is mqtt.2030.ltsapis.goog.

In future versions of this library, the MQTT domain and certificates will be changed for long term support (LTS) to:

• MQTT LTS Domain - mqtt.2030.ltsapis.goog
• Primary cert - https://pki.goog/gtsltsr/gtsltsr.crt
• Backup cert - https://pki.goog/gsr4/GSR4.crt

The following examples show how to regenerate the certificates:

Create Registry keys

openssl genpkey -algorithm RSA -out ca_private_registry.pem -pkeyopt rsa_keygen_bits:2048
sudo openssl req -x509 -new -nodes -key ca_private_registry.pem -sha256 -out ca_cert_registry.pem -subj "/CN=unused"
gcloud iot registries credentials create --path=ca_cert_registry.pem  --project=secret  --registry=secret --region=us-central1

Create Elipitic device keys

openssl ecparam -genkey -name prime256v1 -noout -out ec_private_device1.pem
sudo openssl req -new -sha256 -key ec_private_device1.pem -out ec_cert_device1.csr -subj "/CN=unused-device"
sudo openssl x509 -req -in ec_cert_device1.csr -CA ca_cert_registry.pem -CAkey ca_private_registry.pem -CAcreateserial -sha256 -out ec_cert_device1.pem
gcloud iot devices create device1 --region=us-central1  --registry=secret  --public-key path=ec_cert_device1.pem,type=es256-x509-pem

Print info to copy to code

openssl ec -in ec_private_device1.pem -noout -text
echo "Copy private part of above to esp8266 code"

For more information

• Access Google Cloud IoT Core from Arduino
• Building Google Cloud-Connected Sensors
• Arduino and Google Cloud IoT
• Experimenting with Robots and Cloud IoT Core
• Arduino Hexspider Revisited
• TBD FAQ
• As featured in Google Cloud I/O 2018

Demos

You can see the Arduino client library in action in the Cloud IoT Demo from Google I/O 2018

Error codes, Debugging, and Troubleshooting

The error codes for the lwMQTT library are listed in this header file.

If you're having trouble determining what's wrong, it may be helpful to enable more verbose debugging in Arduino by setting the debug level in the IDE under Tools > Core Debug Level > Verbose.

If you are using newer versions of the ESP8266 SDK, you need to set SSL support to "All SSL Cyphers" and you may need to modify the memory settings in BearSSL by modifying Arduino/cores/esp8266/StackThunk.cpp.

A few things worth checking while troubleshooting:

• Is billing enabled for your project?
• Is the PubSub topic configured with your device registry valid?
• Is the JWT valid?
• Are the values setup in ciotc_config.h appearing correctly in *_mqtt.h?

Known issues

Some private keys do not correctly encode to the Base64 format that required for the device bridge. If you've tried everything else, try regenerating your device credentials and registering your device again with

gcloud iot devices create ...

Some users have encountered issues with certain versions of the Community SDK for Espressif, if you've tried everything else, try using the SDK 2.4.2.

License

Apache 2.0; see LICENSE for details.

Disclaimer

This project is not an official Google project. It is not supported by Google and Google specifically disclaims all warranties as to its quality, merchantability, or fitness for a particular purpose.

google-cloud-iot-arduino's Issues

Write to specific Pub/Sub

Hello, I'm able to connect to library and everything work smoothly.

On google not core I setup specific state topic related to pub/sub

projects/registry1/topics/temp | temp
projects/registry/topics/ledstate | led

Now, I'm wondering how to write and get notified about those specific topics.

Error, client state: -2

Getting an "Error, client state: -2" error. I'm unsure where to start looking for the root cause, as the CloudIoTCoreMQTTClient::mqttConnect() function doesn't make it clear where 'state' is set.

I think it may be related to a JWT auth issue, as when I turn on debug, get the generated JWT, and run it through a debugger (https://jwt.io/#debugger) the signature is invalid with my private key.

Is there any more verbose debug logging that can be used to find out what the cause of an abnormal client state could be?

three bugs

when compiled into esp-idf structure I obtain this errors:

google-cloud-iot-arduino/src/CloudIoTCoreMQTTClient.cpp:94:46: error: format '%ld' expects argument of type 'long int', but argument 3 has type 'int' [-Werror=format=]
     Serial.printf("Waiting: %ld\n", currDelay);

google-cloud-iot-arduino/src/CloudIoTCoreMQTTClient.cpp:147:1: error: control reaches end of non-void function [-Werror=return-type]
 }
 ^

in jwt.cpp:
there is this:

String CreateJwt(String project_id, long long int time, NN_DIGIT *priv_key) {
  CreateJwt(project_id, time, priv_key, 3600); // one hour default
}

the correct is this:

String CreateJwt(String project_id, long long int time, NN_DIGIT *priv_key) {
  return CreateJwt(project_id, time, priv_key, 3600); // one hour default
}

I made the trivial corrections :P, so excuse me if I don't make a PR

Exception after running code for >5mins

I am able to successfully communicate with the HTTP example. However, after running the code for about 5mins or so, I get an exception. Any idea why?

Exception (29):
epc1=0x402155d6 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000004 depc=0x00000000
ctx: cont
sp: 3fff0d70 end: 3fff1290 offset: 01a0

Board-independent MQTT to Google Cloud IoT

Trying to understand how to use Libraries with another board (for ex. Arduino Uno + Ethernet Shield).
Is that possible to do myself with not lots of knowledge?
But, at first, I just can't compile any example because of header issue: cstring in some h-files.
Compiling with Arduino IDE 1.8.7 on Mac OS.

Confirm configuration

Hi :)

Testing the flow of configuration everything work ok . I’m able to send config to device via console or nodejs cloud function without problem .

Data arrive to the device , I do stuffs (ex power up the led ) and so on

Only point Is that I probably not understand how the device acknowledge the conf . Looking at registry console in fact looks like configuration is never confirmed from device .

Do I need to send back special ack message ?

https://ibb.co/Gd4bX8d

Also would add an esp32 specific problem resolution. Seems that power management on esp32 WiFi make the connection lag like hell and generating ex hearbeat problem over long period. Setting :

WiFi.setSleep(false)

Before WiFi begin would improve so much the reliability and speed of connection . This unfortunately happen on esp32 only , esp2866 is not affected

Jwt Refresh and Timing

Hi Gus,

working a lot on this library, you made a really nice job!
I'm actually facing of other pair of points I could not understand:

• JWT refresh: Actually IoT Core need need to refresh key maximum every 24 hours. looking at code seems this is actually not covered I'm saying wrong ?
• Timing. I'm trying (successfully ) to set device config via cloud functions. it works but has a really hi delay ( about 9 sec). would u suggest put my attention on firmware side or this kind of delays are normal into Mqtt enviroments?

TRYING TO CONNECT SPARKFUN ESP-32 THING TO GOOGLE CLOUD IOT

I have some problems trying to connect the microcontroller sparkfun esp32 thing to google cloud iot. My objetive is to send telemetry from the groove data sensor to google cloud iot. In my case, I am using the DTH11 sensor to send both temperature and humidity.

Here is the error on Arduino Ide program as a result of executing the google cloud iot library skectch obviously changing some values to fulfill my requirements:

Connecting to WiFi
Waiting on time sync…
Connecting to cloudiotdevice.googleapis.com
Verifying certificate
Error: Certificate not verified! Perhaps the fingerprint is outdated.
GET /v1/projects/product12/locations/europe-west1/registries/iot-sample-registry/devices/iot-sample-device/config?local_version=0 HTTP/1.1

Connecting to cloudiotdevice.googleapis.com
Waiting for response…
headers received
7b

{
“error”: {
“code”: 401,
“message”: “No \”authorization\” header found.”,
“status”: “UNAUTHENTICATED”
}
}

My doubt is when I create the certificates , Do I need to save them at any directory at my pc? It looks like it doesn’t find the certificates when is connecting to google cloud iot once I runned the script at Arduino IDE.

I can send you my scripts on Arduino IDE with those changes, so you can understand better my problem.

If it seems difficult to do, I could try to use Mongoose Os which is a firmware that supports ESP32 and can upload telemtry to google cloud iot, but I don't know if it supports groove sensors.

Thank you!

Publish state

I could setup a working example with publish telemetry but I still cannot make the publish state work .
Actually , for test , I used same payload of telemetry and, on server side , I used the same “telemetry topic” for the state . Looking on iot core interface look like device never sent an information state , the code on device look running well . Am I missing something ?

keepalive/heartbeat on google iot core

In google cloud IoT Core the heartbeats (PINGREQ) are billed.
In my test (see the screenshot) with this librari I've 8 heartbeats/minute!!!

I tested with 60seconds (the default is 10 seconds) but the results are the same: 8 heartbeats/minute!!!
How to reduce these useless heartbeats?

Not leaving the while loop (connecting)

I am trying the MKR1000 lwMQTT example.
I created everything in the GCP following the commands in README.md, and added the correct values in ciotc_config.h.
The board connects to wifi, is refreshing the JWT, but doesn't exit the while loop after the "connecting" message.
The loop returns "0" for both, the lastError and returnCode.
I also printed the returned jwt before the lastError and returnCode, and it looks correct.
There are no logs in the GCP's Stackdrive.
I don't understand why the device doesn't connect.

403 Error

Hi,

We have WeMos D1 R2 mini connected to the Arduino board. Our setup works well with BLYNK app but we would like a customized solution using GC. However, we receive 403 error as follows:

{
  "error": {
    "code": 403,
    "message": "The caller does not have permission",
    "status": "PERMISSION_DENIED"
  }
}

We followed all the instructions related to devices, pub/sub registrations.

You can see IAM config below:
IAM Members: https://imgur.com/luq0hkF
IAM Roles: https://imgur.com/a/rYD7hjc

I also set certificate expiry to 12 hours just in case.

For example, should we add a certificate to registries section?
https://imgur.com/CB0uRJ2

We'll appreciate for your help.

Corrupted memory

I tried to use the MQTT ESP32 sample and simplify it.

A call to mqttClient.setCallback(callback); in the setup() should be enough.
By logging the address of callback in PubSubClient.cpp, I realized that the address changed between the PubSubClient::setCallback() and the PubSubClient::loop().
The example resets the callback pointer just before subscribing to the config topic.
If you comment that, the example will crash when calling the callback.

I lost a lot of time before understanding that.
I do not know where the memory get corrupt.

I have other projects using PubSubClient and a Mosquitto server without any issue.
I think it's related to the IoT Core layer.

ESP8266_HTTP example not working.

Refreshing JWT

ets Jan 8 2013,rst cause:4, boot mode:(3,7)

wdt reset

refreshing jwt doesn't work

Hi,
I use heltek wifi kit 32 device and Esp32-ssd1306 example to connect to google iot.
Following the steps, it's good for me to connect to google cloud.
Unfortunately, I get trouble when I like to refresh jwt.
After many trouble shooting, I find a question that the jwt string produced from createJWT function is invalid signature at https://jwt.io(The header and payload look good from the jwt string).
I try to use the signature verified jwt string which is produced from https://jwt.io to connect to google iot and refresh jwt, it does work fine.
Does the invalid signature jwt cause the refresh failed? or Do I have something wrongs?
Could you please give me a hand, thank you very much.

hi..I want to know is it possible to store data in firebase and have the sub / pub in the same function using the iot core in google cloud? any suggestion?

Cannot connect MQTT using esp8266

I can not connect MQTT and I receive an error is : " last error :-10 return code : 5". Could someone tell me where I am wrong?

publishTelemetry with binary data

Please support publishTelemetry with binary data (aka const uint8_t* payload, unsigned int plength, like PubSub library)

Array bounds error CloudIoTCoreDevice.cpp:91

Trying to run esp32-mqtt compiling give this error:
CloudIoTCoreDevice.cpp: In member function 'void CloudIoTCoreDevice::fillPrivateKey()':
CloudIoTCoreDevice.cpp:91:13: error: array subscript is above array bounds [-Werror=array-bounds]
priv_key[8] = 0;

in CloudIoTCoreDevice.h:30, priv_key is declared:
NN_DIGIT priv_key[8];

So this does seem to be an out of bound memory access on CloudIoTCoreDevice.cpp:91.

Commenting this line out solves the problem but I'm not sure the intent of this assignment.

ESP32 MQTT-GCP connectivity Example code:setCAcert()

1. The key has to be in hex format
2. It has to be typecasted to unit_8* format
3. The key size has to be passed as second parameter.

Solution : use the "xxd" command on DER format of the public key.

How to obtain Root certificate?

I'm trying to run the esp8266 mqtt sample but cannot get my device to connect. I assume this is because I did not change the ca.crt file that is in the data folder before uploading it to my microcontroller. Which root crt should I be using?

Error: Header Includes not found

Hello, this may be a silly question, but I'm newbie in iot.
Recently I try to upload esp8266-http example in node mcu ESP8266MOD,
and it give error

where can i get this rBase64 header file

ESP32 lwmqtt connection denied

Hello

I am trying out the v1.1.0 esp32-lwmqtt sample with the following board with connection denied on mqtt_connect

https://www.cnx-software.com/2017/10/13/this-ttgo-board-combines-esp32-lora-radio-and-oled-display-for-just-10/
I rechecked my device, registry, project and private key ciotc config. Infact I follow the same commands (even the names) in readme to tryout things first time by keeping it simple.

On the root certifcate part, the openssl command in the instructions of ciotc returns a certifcate chain with two certificates in the gcould shell and I am not sure which one to copy. I just tried with the first certificate.

And also it says to copy the content to root.cert. I do not understand where the root.cert should be placed (or flashed into esp32 with some tool?!?!)

Any help is appreciated. Thanks

Add support for RSA keys

We originally were targeting the ATmega328p, which constrained us to Elliptic Curve, with faster MCUs available, it should be feasible to also support RSA-256 keys.

This issue is to capture any progress and requirements for RSA.

Error, client state: -1

in the esp32-mqtt example I obtain always this result. I'm using platformio with platform espressif 32 v1.5.0.

Exponential Back-off

All of the code where devices connect needs to use exponential backoff to prevent DOS-style connection attempts in the case of large numbers of devices being unable to connect.

private key str length variance

[bytes have been changed to protect the innocent]

depending on the keygen, the step to get an encoded private string for MQTT example:

openssl ec -in ec_private.pem -noout -text

generates hex string of a different number of bytes:

const char* private_key_str =
    "63:dc:3c:27:fe:4c:11:c4:a1:21:f2:90:70:b4:42:"
    "e0:02:12:95:25:2a:cf:31:fc:78:95:9f:99:54:4d:"
    "2b:a9";    

const char* private_key_str =   
    "00:ab:64:4a:10:ed:7e:d8:4b:8a:0f:ac:12:94:27:"
    "2d:61:10:02:fc:45:06:8c:ab:bc:07:cd:50:05:ef:"
    "32:a1:15";    

The shorter form works, the longer form does not.

fill_priv_key is at least one of the functions that would need to be modified, not sure about others.

Esp8266-http error403

I understand you have mentioned that you have no idea why error 403 pops up. I keep getting this error whenever I try to run the http code.
{
"error": {
"code": 403,
"message": "The caller does not have permission",
"status": "PERMISSION_DENIED"
}
}
Do you think this error is because of some key mismanagement?

ESP8266 MQTT?

This async MQTT library supports SSL+TLS. If it possible to use MQTT provided by this library to connect to Google IoT? All I see is the example for MQTT for ESP32.

Add Enterprise WiFi settings to configurations

If the boards support it, add enterprise configuration:

#define EAP_ANONYMOUS_IDENTITY "[email protected]"
#define EAP_IDENTITY "[email protected]"
#define EAP_PASSWORD "password"

And use it when starting WiFi:

  esp_wifi_sta_wpa2_ent_set_identity((uint8_t *)EAP_ANONYMOUS_IDENTITY, strlen(EAP_ANONYMOUS_IDENTITY)); 
  esp_wifi_sta_wpa2_ent_set_username((uint8_t *)EAP_IDENTITY, strlen(EAP_IDENTITY));
  esp_wifi_sta_wpa2_ent_set_password((uint8_t *)EAP_PASSWORD, strlen(EAP_PASSWORD));
  esp_wpa2_config_t config = WPA2_CONFIG_INIT_DEFAULT();
  esp_wifi_sta_wpa2_ent_enable(&config); //set config settings to enable function

string.h -> String.h conversion in pull_crypto.sh

After getting header-not-found compile errors in my dev environment (linux, building for ESP32), I discovered that pull_crypto.sh is changing all includes of string.h in src/crypto to String.h. Switching these back to string.h resolved the problem.

Is there a reason this conversion is being done? My understanding is that the string.h desired here is the standard C string.h with prototypes for memcpy and the like. All of the instances of this file I have in my Arduino IDE are all lowercase.

memcopy not found

I am getting error:
Arduino: 1.8.1 (Windows 10), Board: "WeMos D1(Retired), 80 MHz, 921600, 4M (3M SPIFFS)"

C:\Users\kashy\Documents\Arduino\libraries\google-cloud-iot-arduino-master\src\crypto\nn.cpp: In function 'void NN_Assign(NN_DIGIT*, NN_DIGIT*, NN_UINT)':

C:\Users\kashy\Documents\Arduino\libraries\google-cloud-iot-arduino-master\src\crypto\nn.cpp:85:35: error: 'memcpy' was not declared in this scope

memcpy(a, b, digits*NN_DIGIT_LEN);

                               ^

C:\Users\kashy\Documents\Arduino\libraries\google-cloud-iot-arduino-master\src\crypto\nn.cpp: In function 'void NN_Div(NN_DIGIT*, NN_DIGIT*, NN_DIGIT*, NN_UINT, NN_DIGIT*, NN_UINT)':

C:\Users\kashy\Documents\Arduino\libraries\google-cloud-iot-arduino-master\src\crypto\nn.cpp:248:11: error: 'NULL' was not declared in this scope

if(a != NULL) {

PubSubClient Issues (and fixes)

Couple of comments from someone who has just recently been able to get this client to work with an ESP32. Perhaps a README update might be helpful for others?

I ran into 2 issues which were resolved by PubSubClient fixes...

1. In the README for Google Cloud IoT JWT, it says to comment out line 266 of the PubSubClient.cpp. That line is now actually line 272; might be better to say which code needs to be commented out

2. I was receiving a very frustrating error in my device info in IOT Core - "mqtt: SERVER: The connection was closed because MQTT keep-alive check failed.". I updated the MQTT_KEEPALIVE in PubSubClient.h, however that didn't help. It turns out the non-intuitive root cause was that my MQTT payload was too big... updating the MQTT_MAX_PACKET_SIZE from 128 to 256 solved the problem.

Basic MKR Appears to Fail at Fill Private Key

Hi, thanks so much for all your work on this.

Advanced apologies as the following is most likely due to my lack of understanding rather than anything being wrong with the code - I'm new to Arduino...

I'm trying to run the Basic MKR example - it seems to run as far as Refreshing JWT and returning a string but then jumps over to printing time and LED OFF. My IoT Core console doesn't seem to be registering the connection as under last seen it's showing -- so I assume somethings going wrong in the fill private key section and it's eventually timing out and jumping on to the next bit of code?

Here's what my serial reads:

Connecting to WiFi
14:11:02.445 -> Waiting on time sync...
Connecting to: cloudiotdevice.googleapis.com
Getting jwt.
14:11:03.477 -> Refreshing JWT
eyJhbGciO......

14:11:12.114 ->
14:11:12.114 -> LED OFF

14:11:16.110 ->
14:11:16.110 -> LED OFF

14:11:20.159 ->
14:11:20.159 -> LED OFF

Any pointers would be greatly appreciated,

Many thanks,

Sam

Question:

hi gus,

still exploring your code. I see in device a variable called:

CONFIG_CALLBACK_SIGNATURE_PARAM

can u explain what is used for in case is not NULL ?

WiFi and pubsub instances

Actually WiFi and pubsub instances are declared inside the class, privately . For the project i’m making I need to create those instances outside in my setup() and access it . So , could WiFi and pubsub be passed as parameter whe I create the device object in my code ?

Add PlatformIO to the project to improve development workflow

As I mentioned on the PR #4, I use PlatformIO for embedded environment. I never used for developing a library but I think that we can have a lot of advantages, like declaring the project dependencies from Git or from other Arduino Libraries. This way the current "compile" flow on the jwt folder can be changed to use PlatformIO.

http://docs.platformio.org/en/latest/librarymanager/config.html

Also, we can also how to configure a CI environment to test the library on different boards the project. An example of this can be seen in the PubsubClient project:

https://github.com/knolleary/pubsubclient

What do you think of this? Make sense for this project?

How to publishTelemetry/State with MKR1000?

Hi,
I have seen the examples/Basic-MKR1000/ but there isn't any publish data.
I have tried to use the CloudIoTCoreMQTTClient on MKR1000 but the class use WiFiClientSecure and the code doesn't compile.

Someone have an example to publishTelemetry/State with MKR1000?

thanks

error: 'NN_DIGIT' does not name a type

when i try to compile example Esp32 mqtt, it gives error

error: 'NN_DIGIT' does not name a type

Esp32-lwmqtt doesn't connect if xTaskCreate's priority is high

Basically I added XTaskCreate(sendHumidity, "sendHumidity", 10000, Null, 3,NULL) in the setup() from the example, but somehow esp32 is unable to connect to Google cloud over mqtt because of this, but when I change the task priority from 3 to 1, then it connects...
What might be the cause for this? I also tried other examples as well and they all seem to have the same issue as long as I change the task pirotiry to 1 then it works.
I am using PlatformIO.

Create CloudIoTCoreHTTPClient in library

In CloudIoTCoreDevice we should add:

• A common exponential backoff function based on ESP8266 / ESP32 HTTP examples
• Creates a common set of headers for GetConfig, SetState, and SendTelemetry

We should then create an HTTP equivalent to the MQTT client type that:

• Manages lifecycle of the HTTP connection
• Can be constructed from our supported device types

Cant connect Adafruit ESP32 Huzzah

Going off the Esp32-lwmqtt sample I am trying to connect my Adafruit ESP32 Huzzah board. Previously I had it working with using a RSA256 key that I would get from an AppEngine endpoint but I want the device to be able to generate the JWT to remove the app engine endpoint call.

I used openssl to create the public/private ec.pem keys
Replaced the private_key_str with the priv value from running the command

openssl ec -in ec_private.pem -noout -text

When I run the program I print the JWT to serial and put it in jwt.io and it says the JWT has a "Invalid Signature" so naturally the mqtt library kicks back saying back username or password.

Did I miss something?

Also what is the root_cert used for? I dont see it being used anywhere in the esp32 files

ESP32 Subscribe to Google Cloud IoT Topic

The current example sketch shows how to publish to pubsub, but does the current library have support for a device to subscribe to a separate topic in Google Cloud IoT?

esp32 advanced

Hi Man :)

tested the new esp32 advanced and got this strange behaviour. I'm using exactly same previous ctcio_config with working key. Seems to connect then die then reconnect and so on ...

I have not touched code except for CTCIO . saw u put a waiting new waiting method in code, btw any way to have more info on debug ?

Publish message
Connecting to mqtt.googleapis.com
MQTT connecting ...
JWT now:
eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE1NDU0MTExNjAsImV4cCI6MTU0NTQxNDc2MCwiYXVkIjoiY2hhcmdlc3BsIn0=.m6ZyoAWPmyumJZB6ZsXmKcpW1HgPZSsx/r7+8OHpXImXoy9A+Ww/RLkbpVhQbVEGgWZIj1jwfIGhrF07BbKKgw==
projects/spl/locations/europe-west1/registries/pipger/devices/esp32_02
eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE1NDU0MTExNjAsImV4cCI6MTU0NTQxNDc2MCwiYXVkIjoiY2hhcmdlc3BsIn0=.m6ZyoAWPmyumJZB6ZsXmKcpW1HgPZSsx/r7+8OHpXImXoy9A+Ww/RLkbpVhQbVEGgWZIj1jwfIGhrF07BbKKgw==
Waiting: 5542
Connecting to mqtt.googleapis.com
MQTT connecting ...
JWT now:
eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE1NDU0MTExNjcsImV4cCI6MTU0NTQxNDc2NywiYXVkIjoiY2hhcmdlc3BsIn0=.BOSlS4ZR4j/JatL7nA4NiQ3A6iTK0pF1R3XK2Tc0OBmsrfjLcsuLbUg2NM2hYWH0jbWBJAoVB7misybBnNKhvw==
projects/spl/locations/europe-west1/registries/pipger/devices/esp32_02
eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE1NDU0MTExNjcsImV4cCI6MTU0NTQxNDc2NywiYXVkIjoiY2hhcmdlc3BsIn0=.BOSlS4ZR4j/JatL7nA4NiQ3A6iTK0pF1R3XK2Tc0OBmsrfjLcsuLbUg2NM2hYWH0jbWBJAoVB7misybBnNKhvw==
Waiting: 5083
Publish message
Connecting to mqtt.googleapis.com
MQTT connecting ...
projects/spl/locations/europe-west1/registries/pipger/devices/esp32_02

Waiting: 5309
Connecting to mqtt.googleapis.com
MQTT connecting ...
projects/spl/locations/europe-west1/registries/pipger/devices/esp32_02

Waiting: 5768
Publish message
Connecting to mqtt.googleapis.com
MQTT connecting ...
projects/spl/locations/europe-west1/registries/pipger/devices/esp32_02

Waiting: 5309
Connecting to mqtt.googleapis.com
MQTT connecting ...
projects/spl/locations/europe-west1/registries/pipger/devices/esp32_02

Waiting: 5268

MQTT code - Crash cused by lack of disable watchdog before getjwt

Mqtt code crashes while executing getjwt. This is caused when the CPU heavy crypto code is executed.

Solution: Disable CPU watchdog before getJWT and enable atfer returning from getJWT.

In Http example: fingerprint does not work, instead use RS/EC key in Hex format

Fingerprints are deprecated.
The Following code in the Http example's config has to be changed.
const char* fingerprint =
"7C:D4:99:11:FE:FC:0D:78:C0:A9:C1:18:52:1D:3F:0B:8B:38:C9:90";

Solution: Instead use RSA/EC key in Binary format.

Use "xxd" command on der format of the public key to obtain the Hex format of the key aling with its length. : https://www.poftut.com/use-linux-xxd-command-tutorial-hex-binary-operations-example/

API support for multiple topics

Since February 21, 2018 (https://cloud.google.com/iot/docs/release-notes) "device registries can now have multiple associated Cloud Pub/Sub topics". Your API support only one topic. I'm in wrong?

https://cloud.google.com/iot/docs/how-tos/devices#creating_a_device_registry_with_multiple_pubsub_topics

Move NTP server to ciotc_config.h

To make it more convenient and faster for local NTP, move NTP to ciotc_config.h.

how to configure keys ?

I tried to follow documents on here and generated RSA-256. And uploaded public key in the cloud. but when I try to do
openssl ec -in rsa_private.pem -noout -text

I get this.

read EC key
unable to load Key
140735833293704:error:0608308E:digital envelope routines:EVP_PKEY_get1_EC_KEY:expecting a ec key:p_lib.c:328:

how do I go with this ? I am embedded engineer I don't understand a lot of openssl :P I am just starting to use google IoT core. I have previously used AWS IoT. but those generate certs and keys online also some steps you can generate locally but ca cert needs to be added to AWS IoT.

ESP8266 MQTT - Callback function is null - Causes crash (https://github.com/GoogleCloudPlatform/google-cloud-iot-arduino/tree/master/examples/Esp8266-http) is the only supported version. I I have been working on porting MQTT to work for the 8266 but there's some strange issue that causes crashes.

Originally posted by @gguuss in #27 (comment)

Mqtt crashes at multiple points. The callback function pointer is found to be Null and crashes. I suspect memory over write or mishandling of the call back pointer.