Update README.md

Author: rjtokenring

README.md

@@ -2,6 +2,7 @@
 
 This project provides a way to extract time series samples from Arduino cloud, publishing to a S3 destination bucket.
 Data are extracted at the given resolution via a scheduled Lambda function. Then samples are stored in CSV files and saved to S3.
+By default, data extraction is performed every hour, extracting samples aggregated at 5min resolution. Non numeric values like strings are sampled at the given resolution.
 
 ## Architecture
 
@@ -12,11 +13,11 @@ By default, all Arduino things present in the account are exported: it is possib
 
 CSV produced has the following structure:
 ```console
-timestamp,thing_id,thing_name,property_id,property_name,value
-2024-09-04T11:00:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,3.000
-2024-09-04T11:01:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,7.000
-2024-09-04T11:02:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,11.000
-2024-09-04T11:03:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,15.000
+timestamp,thing_id,thing_name,property_id,property_name,property_type,value
+2024-09-04T11:00:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,FLOAT,3
+2024-09-04T11:01:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,FLOAT,7
+2024-09-04T11:02:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,FLOAT,11
+2024-09-04T11:03:00Z,07846f3c-37ae-4722-a3f5-65d7b4449ad3,H7,137c02d0-b50f-47fb-a2eb-b6d23884ec51,m3,FLOAT,15
 ```
 
 Files are organized in S3 bucket by date and files of the same day are grouped.
@@ -97,4 +98,4 @@ To compile code:
 ```console
 foo@bar:~$ ./compile-lambda.sh
 arduino-s3-integration-lambda.zip archive created
-```
+```