Esphome string conversion

ESPHome
1

Hi

I’m trying to parse JSON in esphome using json::parse_json, but I think I’m hitting upon some weird wide character/utf8 type issues.

Following the example here HTTP Request — ESPHome under “GET values from a JSON body response” I have a sample configuration below: -

substitutions:
  device_name: screen-2
  friendly_name: Screen 2

esphome:
  name: $device_name
  friendly_name: $friendly_name

esp32:
  board: esp32dev
  framework:
    type: arduino

logger:

api:
  encryption:
    key: "obfuscated"

ota:
  password: "obfuscated"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Screen-2 Fallback Hotspot"
    password: "obfuscated"

captive_portal:

json:
  
http_request:
  id: http_request_data
  useragent: esphome/device
  timeout: 10s

button:
  - platform: template
    name: Test Button
    on_press:
      then:
        - http_request.get:
            url: http://ip.jsontest.com/
            on_response:
              then:
                - lambda: |-
                    json::parse_json(id(http_request_data).get_string(), [](JsonObject root) {
                      ESP_LOGD("one", "The value is: %s", root["ip"]);
                      ESP_LOGD("two", root["ip"]);
                    });

When I press the button, this calls a website which returns IP address in JSON. However, when I try and do something with the parsed output, I get issues if I try and use it as a string. See the first line in the output below: -

[23:30:46][D][one:052]: The value is: \x80\x80p"\xfb?X"\xfb?Y\xb3@?`
[23:30:46][D][two:053]: 69.69.69.69
[23:30:46][D][http_request:099]: HTTP Request completed; URL: http://ip.jsontest.com/; Code: 200; Duration: 302 ms

That’s with logging using %s, so clearly it isn’t just a char* - I think it’s probably utf8 or similar wide encoding. And if I pass it directly as per the “two” logger above, it comes out correct (albeit I’ve obfuscated the address).

So how do I make the output be a usable, displayable string? My actual use case is to display on a screen, and often I use .c_str() but it’s not a std::string object so that doesn’t work. I’ve tried casting with (char), doing sprintf() with “%ls” and can’t get a human readable output.

Any ideas?

Thanks

2

Anyone? Bueller?

3

Have you tried a different source? It may be because it is an IP address and it gets confused trying to convert it treating it as a number.