diff --git a/lib/zh_avr_pcf8574 b/lib/zh_avr_pcf8574
index 9a6d82f..3fa55b8 160000
--- a/lib/zh_avr_pcf8574
+++ b/lib/zh_avr_pcf8574
@@ -1 +1 @@
-Subproject commit 9a6d82fb64d9bb6a591b650c56e714f427055197
+Subproject commit 3fa55b8fa23d5263cf99a3666f6a1051a2bf71c4