From dcfaba0069e1f49973050fb06539f31a94c7324b Mon Sep 17 00:00:00 2001
From: Baozhu Zuo <zuobaozhu@gmail.com>
Date: Thu, 27 Apr 2017 17:41:39 +0800
Subject: [PATCH] update readme file

---
 README.md | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 55ebce0..94ef4f7 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ sudo BRANCH=next rpi-update
 sudo reboot
 ```
 
-Install matching kernel header files:
+Install matching kernel header files(come from https://www.raspberrypi.org/forums/):
 eg. Get your kernel verson "uname -r", then
 ```
 wget  https://www.niksula.hut.fi/~mhiienka/Rpi/linux-headers-rpi/linux-headers-4.9.13-v7%2B_4.9.13-v7%2B-2_armhf.deb 
@@ -54,8 +54,9 @@ pi@raspberrypi:~/seeed-voicecard$
 ```
 Next apply the alsa controls setting
 ```
-alsactl --file ./asound.state restore
+sudo alsactl --file ./asound.state restore
 ```
+If you want to change the alsa settings, You can use "sudo alsactl --file ./asound.state store 1" to save it.
 
 Test:
 ```