Add : do not try again to write data on flash if it failed with read-only error

circuitpython/main.py

@@ -23,7 +23,7 @@ Use with:
  * Bosch BME280 sensor (air temperature, humidity, atmospheric pressure) on I2C
 
 TODO for v1 :
- * write data on flash drive
+ * write data on flash drive (work-in-progress)
  * send data through UART (one more !)
 """
 __version__ = 0.1
@@ -133,6 +133,7 @@ class Data:
                                                       self.data['BME280']['press']['val']))
         except OSError as e:
             print("Err. {} : R-O FS".format(e))
+            backup_data = False      #to avoid trying again till next reset
 
 
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