Low cost / low power sleep / WiFi Camera

I was thinking that it could be useful for someone that just needs to read a water metric or anything from a remote place in a different network, it could be useful to try the bigiot.net example.

The only disadvantage is that is in Chinese and online translators don't seem to work well to translate private admin dashboards (Or at least not Google and Bing that I tried)

So to simplify it in a few steps you need to : 

1. Register in bigiot : https://www.bigiot.net/User/register
   
2. Create a device and an interface
3. Use the Apikey, Device ID and interface ID in the demo example here:

https://github.com/martinberlin/ESP32-Camera/tree/master/examples/BIGIOT_UpdateImage

I modified the original code to add WiFi Manager and to publish some information in the oled display.

Then you can make a camera that uploads an image every X seconds without needing to code or prepare any backend for this, you can see a preview here:

https://twitter.com/martinfasani/status/1086506846679109632

So after that and uploading the code with the right credentials you can log in to BIGIOT and just click on the Camera device eye, to see the latest picture, or also see a log of the sent uploads.

If you select the interface to be public, then the URL is public as well:

https://www.bigiot.net/Public/upload/inputImg/9110/7832/ -> No matter what settings I've tried, it keeps always the last 9 images.

I though it was an interesting thing to share. If it does not have much to do with the project feel free to move this away @James Newton 

While the standard ESPAsyncWebServer does work on the ESP32, the author does not support the Arduino IDE for it's use, preferring PlatformIO. I want to stay with the ugly beast because it makes the code accessible to a wider range of people (Ok, really I just don't want to learn Yet. Another. IDE). Specifically, the the examples for web servers do not work in the Arduino IDE. However, this page provides a series of examples (See "Related Posts") which document how to make it work. 

https://techtutorialsx.com/2018/08/14/esp32-async-http-web-server-websockets-introduction/

e.g. a simple web server via access point:

#include "WiFi.h"
#include "ESPAsyncWebServer.h"
 
const char *ssid = "MyESP32AP";
const char *password = "testpassword";
 
AsyncWebServer server(80);
 
void setup(){
  Serial.begin(115200);
 
  WiFi.softAP(ssid, password);
 
  Serial.println();
  Serial.print("IP address: ");
  Serial.println(WiFi.softAPIP());
 
  server.on("/hello", HTTP_GET, [](AsyncWebServerRequest *request){
    request->send(200, "text/plain", "Hello World");
  });
 
  server.begin();
}
 
void loop(){}

 I'm assuming the Async Web Server is still a better option than the built in web server which requires polling (VERY unstable if you do anything of note in the main loop). Please let me know if you have a better option. 

Got the TTGO-CAMERA hardware. It works... ish... the picture quality is... less than fantastic. Here is a sample:

https://hackaday.io/project/162968/gallery#f19805f77b13adad91ca41d4d607a9ec

Both units have about the same picture quality. If anything, this was the better one. 

I included some objects in the foreground so you can see the focus isn't any better there. 

I'm not at all convinced that lousy focus is going to work for reading even the most bold meters. Anyone have ideas on improving the optics? Lense seem very glued on, not removable. So it would need "corrective lenses" and I'm not an optician.

Compute Engine can be setup to use Googles (very nice) image processing tools:
https://cloud.google.com/functions/docs/tutorials/ocr

The nice thing about google is that you get a certain amount each month free. And they use Node.js so moving part of it local is easy. The down side is that you must hope google doesn't abandon the service, change the pricing, or generally dick something else up on you. Hopefully, others have better options for local FOSS OCR.