Update:
I searched for solutions, and tried the instruction from one post After Firmware update, one motor runs constantly on reboot,
I tried  sudo bash firmware_update_v16.sh, and it seemed works. Gopigo is moving forward again~~
To make sure it’s really good now, I did the troubleshoot,
can anyone help check my latest log to see if anything is wrong now?
Check space left
Filesystem      Size  Used Avail Use% Mounted on
/dev/root       3.6G  2.8G  615M  82% /
devtmpfs        427M     0  427M   0% /dev
tmpfs           432M     0  432M   0% /dev/shm
tmpfs           432M  6.1M  425M   2% /run
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           432M     0  432M   0% /sys/fs/cgroup
/dev/mmcblk0p1   63M   21M   43M  33% /boot
tmpfs            87M     0   87M   0% /run/user/1000
Check for dependencies
python 2.7.9-1 install ok installed
python-pip 1.5.6-5 install ok installed
git 1:2.1.4-2.1+deb8u2 install ok installed
libi2c-dev 3.1.1+svn-2 install ok installed
python-serial 2.6-1.1 install ok installed
python-rpi.gpio  unknown ok not-installed
i2c-tools 3.1.1+svn-2 install ok installed
python-smbus 3.1.1+svn-2 install ok installed
arduino 2:1.6.0 install ok installed
minicom 2.7-1 install ok installed
scratch 1.4.0.6~dfsg1-5 install ok installed
wiringPi Not Found (ERR)
wiringPi Found
I2C already removed from blacklist
SPI already removed from blacklist
Check for addition in /modules
I2C-dev already there
i2c-bcm2708 already there
spi-dev already there
Hardware revision
gpio version: 2.36
Copyright © 2012-2015 Gordon Henderson
This is free software with ABSOLUTELY NO WARRANTY.
For details type: gpio -warranty
Raspberry Pi Details:
Type: Pi 3, Revision: 02, Memory: 1024MB, Maker: Sony
- Device tree is enabled.
*–> Raspberry Pi 3 Model B Rev 1.2 
- This Raspberry Pi supports user-level GPIO access.
 
Check the /dev folder
i2c-1
spidev0.0
spidev0.1
ttyAMA0
USB device status
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/5p, 480M
|__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=smsc95xx, 480M
Checking for Atmega chip
avrdude: Version 5.10, compiled on Jun 18 2012 at 12:38:29
Copyright © 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright © 2007-2009 Joerg Wunsch
     System wide configuration file is "/etc/avrdude.conf"
     User configuration file is "/root/.avrduderc"
     User configuration file does not exist or is not a regular file, skipping
     Using Port                    : unknown
     Using Programmer              : gpio
     AVR Part                      : ATMEGA328P
     Chip Erase delay              : 9000 us
     PAGEL                         : PD7
     BS2                           : PC2
     RESET disposition             : dedicated
     RETRY pulse                   : SCK
     serial program mode           : yes
     parallel program mode         : yes
     Timeout                       : 200
     StabDelay                     : 100
     CmdexeDelay                   : 25
     SyncLoops                     : 32
     ByteDelay                     : 0
     PollIndex                     : 3
     PollValue                     : 0x53
     Memory Detail                 :
                              Block Poll               Page                       Polled
       Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
       ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
       eeprom        65     5     4    0 no       1024    4      0  3600  3600 0xff 0xff
       flash         65     6   128    0 yes     32768  128    256  4500  4500 0xff 0xff
       lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
       hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
       efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
       lock           0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
       calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
       signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00
     Programmer Type : GPIO
     Description     : Use sysfs interface to bitbang GPIO lines
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e950f
avrdude done.  Thank you.
Checking I2C bus for devices
Checking I2C bus 0
Error: Could not open file /dev/i2c-0' or/dev/i2c/0’: No such file or directory
Checking I2C bus 1
 0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
Checking for firmware version and CPU Speed and Voltage
v 1.6
CPU speed: 2
10.05 V
CHECKING ENCODER READINGS
0 0
Both motors moving Forward with LED On
after 5 sec 161 155
Both motors stopped with LED Off
None after stop cmd 167 160
None after 2 more sec 169 160
Both motors moving back with LED On
after 5 sec 282 262
Both motors stopped with LED Off
None after stop cmd 282 262
None after 2 more sec  282 262
CHECKING ENCODER TARGETING
Initial encoder read vals: 0 0
Enc tgt Status:  1
Enc tgt Status:  0
Final encoder read vals: 0 0
Initial encoder read vals: 0 0
Enc tgt Status:  1
Enc tgt Status:  1
Traceback (most recent call last):
File “/home/pi/Dexter/GoPiGo/Software/Python/tests/enc_tgt_test.py”, line 69, in 
enc_stat=read_enc_status()
File “build/bdist.linux-armv7l/egg/gopigo.py”, line 610, in read_enc_status
File “build/bdist.linux-armv7l/egg/gopigo.py”, line 601, in read_status
IOError: [Errno 5] Input/output error