It's a while since I posted; other projects got in the way, but I'm hoping to get back on track with a project from a couple of years ago. I've done some research on JSON parsing and the aJson library and read items and posts on github and interactive-matter, specifically
http://interactive-matter.eu/blog/2010/08/14/ajson-handle-json-with-arduino/
Most seem to deal with extracting elements of the strings for display, or assume knowledge of techniques that I am not familiar with such as:-
"Storing the original string and the JSON object is a bit too much for your Arduino - it will most likely use up all the memory. Therefore it is better to parse streams instead of strings. A stream in C is a FILE* - on Arduino there are some special streams, but later adapters will be provided. So if you for example read from a FILE* stream you can simply call
aJsonObject* jsonObject = aJson.parse(file);
By that you will not have to store the JSON string in memory."
I'm afraid I've not previously come across streams and FILE* so don't know if these help with what I am trying to do, or if they do, how to use them.
Can anyone help me out by suggesting a means of transferring numerical elements from a JSON response into int variables that I can then manipulate mathematically or use to make decisions within my programme? I belive that I will only need to extract 4 or 5 of them, and all the rest of the data except the associated identification letters are redundant and do not need to be kept.
An example of the type of JSON return I want to process follows, and the numbers of interest are toward the end in the JSON return following the word "REP":
{"SiteRep":{"Wx":{"Param":[{"name":"F","units":"C","$":"Feels Like Temperature"},{"name":"G","units":"mph","$":"Wind Gust"},{"name":"H","units":"%","$":"Screen Relative Humidity"},{"name":"T","units":"C","$":"Temperature"},{"name":"V","units":"","$":"Visibility"},{"name":"D","units":"compass","$":"Wind Direction"},{"name":"S","units":"mph","$":"Wind Speed"},{"name":"U","units":"","$":"Max UV Index"},{"name":"W","units":"","$":"Weather Type"},{"name":"Pp","units":"%","$":"Precipitation Probability"}]},"DV":{"dataDate":"2015-12-15T23:00:00Z","type":"Forecast","Location":{"i":"324268","lat":"51.5859","lon":"-2.1014","name":"MALMESBURY","country":"ENGLAND","continent":"EUROPE","elevation":"86.0","Period":{"type":"Day","value":"2015-12-16Z","Rep":{"D":"WSW","F":"11","G":"27","H":"91","Pp":"50","S":"13","T":"14","V":"VG","W":"12","U":"1","$":"720"}}}}}}