For my ESP32 Project it serves as a server for a LIDAR simulation; meaning that it hosts a server that's open to HTTP requests that contain a param specifying a certain array of scan points it wants. HTTP request
to a server containing a database of Lidar Scan points and receives about 13000 bytes worth of scan-points stores as a JSON response from the serve; which it must then forward to the original client.
So far I have been trying to use the ESP library to processe the data and send it through but it keeps giving me errors and saying that there's no data in the response from the serve(which is incorrect as I have confirmed by manual curl responses from the command line). Is there a better way to acomplish this task ?
[Codebox]static esp_err_t root_get_handler(httpd_req_t *req)
{
static char buf[18000] = {0};
size_t buf_len = sizeof(buf);
char param_value[5];
int content_length = 0;
// Get the value of the 'param' query parameter
if (httpd_query_key_value(req->uri, "param", param_value, sizeof(param_value)) == ESP_OK) {
ESP_LOGI(TAG, "Received param value: %s", param_value);
// Create an HTTP client to send a request to the destination server
esp_http_client_config_t config = {
.url = "http://192.168.97.37:8080",
};
esp_http_client_handle_t client = esp_http_client_init(&config);
esp_http_client_set_method(client, HTTP_METHOD_GET);
// Add the 'param' query parameter to the request
char dest_url[100];
snprintf(dest_url, sizeof(dest_url), "%s?param=%s", "http://192.168.97.37:8080", param_value);
esp_http_client_set_url(client, dest_url);
esp_err_t err = esp_http_client_perform(client);
if (err != ESP_OK) {
ESP_LOGE(TAG, "Failed to open HTTP connection: %s", esp_err_to_name(err));
// Get the response from the destination server
} else {
content_length = esp_http_client_fetch_headers(client);
if (content_length < 0) {
ESP_LOGE(TAG, "HTTP client fetch headers failed");
}
else {
int data_read = esp_http_client_read_response(client, buf, MAX_HTTP_OUTPUT_BUFFER);
if (data_read >= 0) {
ESP_LOGI(TAG, "HTTP GET Status = %d, content_length = %"PRId64,
esp_http_client_get_status_code(client),
esp_http_client_get_content_length(client));
ESP_LOG_BUFFER_HEX(TAG, buf, data_read);
}
else {
ESP_LOGE(TAG, "Failed to read response");
}
}
}
// Cleanup
esp_http_client_cleanup(client);
}
else {
httpd_resp_send_err(req, HTTPD_400_BAD_REQUEST, "Missing 'param' query parameter");
}
return ESP_OK;
}[/Codebox]