Connecting esp8266 to AWS IoT - arduino

Question

I am trying to connect a WeMos D1 mini based on ESP8266 to the Amazon Web Service AWS IoT using https://github.com/heskew/aws-sdk-arduino.
However, when I flash the device, I get a 403 back, with the following message:
"Credential should be scoped to correct service: 'execute-api'. "
Changing
this->awsService = "iotdata";
to
this->awsService = "execute-api";
in AmazonIOTClient.cpp results in a 404:
"No method found matching route things/my-thing/shadow for http method POST."
and, according to this thread the service should be 'iotdata' for the request to succeed.
Has someone had the same problem and figured out a way to get it running? If so, help would be greatly appreciated. Thanks!
Here the full code for the example:
#include <AmazonIOTClient.h>
#include <Esp8266AWSImplementations.h>
#include <AWSFoundationalTypes.h>
#include "keys.h"
const int sleepTimeS = 30;
void printWiFiData();
void printCurrentNetwork();
void publish(const char *topic, String data);
void publishToAWS();
void setup() {
Serial.begin(9600);
Serial.println("Started!");
publishToAWS();
ESP.deepSleep(sleepTimeS * 1000000);
}
void loop() {
}
void printWiFiData() {
// IP address
Serial.print("IP Address: ");
Serial.println(WiFi.localIP());
// MAC address
byte mac[6];
WiFi.macAddress(mac);
Serial.print("MAC address: ");
Serial.print(mac[5], HEX);
Serial.print(":");
Serial.print(mac[4], HEX);
Serial.print(":");
Serial.print(mac[3], HEX);
Serial.print(":");
Serial.print(mac[2], HEX);
Serial.print(":");
Serial.print(mac[1], HEX);
Serial.print(":");
Serial.println(mac[0], HEX);
}
void printCurrentNetwork() {
// SSID
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// signal strength:
Serial.print("signal strength (RSSI): ");
Serial.println(WiFi.RSSI());
}
void publish(const char *topic, String data) {
AmazonIOTClient iotClient;
ActionError actionError;
Esp8266HttpClient httpClient;
Esp8266DateTimeProvider dateTimeProvider;
Serial.println();
Serial.print("Connecting to ");
Serial.print(wifiSsid);
Serial.println("...");
WiFi.begin(wifiSsid, wifiPwd);
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(50);
}
Serial.println("");
Serial.println("WiFi connected");
printCurrentNetwork();
printWiFiData();
delay(50);
Serial.println("Initializing IoT client...");
iotClient.setAWSRegion(awsIotRegion);
iotClient.setAWSEndpoint(awsIotEndpoint);
iotClient.setAWSDomain(awsIotDomain);
iotClient.setAWSPath("/things/my-thing/shadow");
iotClient.setAWSKeyID(awsKeyID);
iotClient.setAWSSecretKey(awsSecKey);
iotClient.setHttpClient(&httpClient);
iotClient.setDateTimeProvider(&dateTimeProvider);
delay(50);
Serial.println("Updating thing shadow...");
MinimalString shadow = ("{\"state\":{\"reported\":{\"text\":" + data + "}}}").c_str();
char* result = iotClient.update_shadow(shadow, actionError);
Serial.print("result: ");
Serial.println(result);
}
void publishToAWS() {
Serial.println("Publishing to AWS IoT Broker");
publish("my-thing/text", "Hello World!");
}
keys.cpp file:
#include "keys.h"
// AWS User Credentials
const char* awsKeyID = "XXXXXXXXXXXXXXXXXXXX";
const char* awsSecKey = "X1xxx23xxxxXXXX34XXxxxxX56xXxxxxxxXx789x";
// AWS IoT
const char* awsIotRegion = "eu-central-1";
const char* awsIotEndpoint = "xxxxxxxxxxxxxx";
const char* awsIotDomain = "iot.eu-central-1.amazonaws.com";
// Init and connect WiFi to local WLAN
char* wifiSsid = "mySSID";
char* wifiPwd = "password";

Answer 1

I can finally contribute something :)
I got this very same example working a few days ago. However I used the same library just a different branch iot-get-shadow-and-cleanup. I don't recall having to make any changes as the one you mentioned:
this->awsService = "iotdata"; to this->awsService = "execute-api";
Here are the correct settings for your AWS endpoint that goes into keys.cpp
awsIotRegion = "us-east-1";
awsIotEndpoint = "amazonaws.com";
awsIotDomain = "axxxxs2pxxxrlx.iot.us-east-1.amazonaws.com";`
Also add delete[] result; to the end of the publish() to save some precious heap space.
I would recommend using the iot-get-shadow-and-cleanup branch since it has fixes for memory leaks.
I made one more change to resolve all issues with running out of heap space when updating the shadow continiously. In AWSClient4.cpp I changed // delete[] server; to delete[] data; - I am not 100% sure if this was necessary but combined with the addition of delete[] result; I was able to update the shadown every minute continuously for an hour without loosing any heap.
Hope this helps.