gzip bin files

pio/gzip-firmware.py

@@ -0,0 +1,29 @@
+Import('env')
+import os
+import shutil
+import gzip
+
+OUTPUT_DIR = "build_output{}".format(os.path.sep)
+
+def bin_gzip(source, target, env):
+    variant = str(target[0]).split(os.path.sep)[1]
+    
+    # create string with location and file names based on variant
+    bin_file = "{}firmware{}{}.bin".format(OUTPUT_DIR, os.path.sep, variant)
+    gzip_file = "{}firmware{}{}.bin.gz".format(OUTPUT_DIR, os.path.sep, variant)
+
+    # check if new target files exist and remove if necessary
+    for f in [gzip_file]:
+        if os.path.isfile(f):
+            os.remove(f)
+
+    # write gzip firmware file
+    fp = open(bin_file,"rb")
+    data = fp.read()
+    bindata = bytearray(data)
+    with gzip.open(gzip_file, "wb") as f:
+        f.write(bindata)
+    fp.close()
+    f.close()
+
+env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", [bin_gzip])