From 754bc6dee355df05a51dba67bd5ad9a0aec01598 Mon Sep 17 00:00:00 2001 From: Black Swift Date: Thu, 28 May 2015 08:57:18 +0300 Subject: [PATCH] Update README.md --- README.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/README.md b/README.md index c9fd8a8..b7c301b 100644 --- a/README.md +++ b/README.md @@ -10,7 +10,7 @@ Default is timer 3 ##Usage -**Start**: *echo " " > /sys/kernel/debug/sqwave*
+**Start**: *echo "<GPIO> <freq>" > /sys/kernel/debug/sqwave*
"*GPIO*" is GPIO number, "*freq*" is square wave frequency in Hz. Maximum frequency with 200 MHz system bus (default clock) is 125 kHz; high settings may result in performance penalty or watchdog reset. **Example**: to blink Black Swift's system LED with 1 Hz frequency: *echo "27 1" > /sys/kernel/debug/sqwave*