Merge pull request #7 from skickar/patch-1

Logging values to .CSV with no SD card

Author: tekktrik

examples/csv_disklogger.py

@@ -0,0 +1,36 @@
+# SPDX-FileCopyrightText: 2022 @Skicka for Adafruit Industries / Hakcat
+# Logging data to .CSV file on CircuitPython Disk
+# SPDX-License-Identifier: MIT
+
+# If you get a read-only filesystem error, add "storage.remount('/', False)" in boot.py
+# Make sure you add a way to reverse this in boot.py or your CP device won't show up via USB
+# See example below:
+# https://learn.adafruit.com/getting-started-with-raspberry-pi-pico-circuitpython/data-logger
+
+import os
+import random
+import circuitpython_csv as csv
+
+# Check if .CSV file is already present. If not, we write CSV headers.
+all_files = os.listdir()  ## List all files in directory
+if "datelog.csv" not in all_files:
+    with open("datelog.csv", mode="w", encoding="utf-8") as writablefile:
+        csvwriter = csv.writer(writablefile)
+        csvwriter.writerow(["Year", "Month", "Day", "Hour", "Minute"])
+
+# Now that the file exists (or already did) we make a random date
+year = random.randint(1999, 2022)
+month = random.randint(1, 12)
+day = random.randint(1, 30)
+hour = random.randint(0, 23)
+minute = random.randint(0, 60)
+
+# We append this to the .CSV file
+with open("datelog.csv", mode="a", encoding="utf-8") as writablefile:
+    csvwriter = csv.writer(writablefile)
+    csvwriter.writerow([year, month, day, hour, minute])
+
+# Finally, we try to read back the last line in the CSV file to make sure it wrote.
+with open("datelog.csv", "r", encoding="utf-8") as file:
+    data = file.readlines()
+    print(data[-1])