More info on connecting via serial connection BY id7:
*** AT YOUR OWN RISK ***
How to got serial console access to your CMU:
- if your CMU is in bootloop,
- stuck at mazda logo
- or you not have access to it via ssh
I go with my car to a service, who specialized in car alarms and gps-es (car electronics)
I said what I want (show pictures, explain,...)
1) I said "I want 1 cable with 3 wires to be installed in my car"
- get out the middle console of car
- get out the CMU fixed with one screw
If you want help to get out the CMU see this video
2) one part of cable connect to CMU TX + CMU RX + ground of car (connected to one screw of CMU)
CMU TX/RX can be reached in two ways:
2a) "the elegant way", put new pins in existing connector to 2S/2T (our service guy don't have this kind of pin)
in this situation you not needed to open the CMU
the whole process is described here http://mazda3revolution.com/forums/attachment.php?attachmentid=209650&d=1498149733
2b) "my way", open the CMU and solder two wires on baseboard of CMU (for service guy this is the easy way if not have compatible pins for that special connector)
3rd wire (ground) can be used from anywhere, I used from external box of CMU from a screw
like the orange cable in http://mazda3revolution.com/forums/attachment.php?attachmentid=209098&d=1497973030
3) other part of 3wire cable with some connector put in fuse box (not need to put in fuse box, this is my personal option. because this cable is not used only once a month)
CONNECTOR: You need something that simply can be connected to your TTL serial converter
if you don't have any type of connector a stereo audio jack is perfect (you need to connect somehow 3 wire, Left/Right/Ground)
solder a stereo jack female
to car part of cable, and solder a stereo jack male
to your TTL convertor
my original post http://mazda3revolution.com/forums/...714-infotainment-project-515.html#post1631825
DON'T left USB serial TTL to be connected always to CMU !!!
left the cable free with a connector! When you need connect the cable to the converter
and the converter to your computer/laptop directly or http://mazda3revolution.com/forums/attachment.php?attachmentid=155833&d=1459377916
4) need a serial to TTL converter
this is a "USB->serial + serial->TTL in one"
you need TTL 3.3V signal converter (exists 5V variants - not good)
I used one "Arduino programmer" (about 2USD) search ebay for "usb serial Arduino programmer uart TTL" (many have 5V power output, no problem, the RX/TX signal need to be 3.3V ==> UART TTL)
My serial convertor have 3.3V power output, RX, TX, GND, +5V power output. we use only RX,TX,GND
if this usb converter (without any wire) is connected to your computer will be recognized as a serial port, possible that you need some driver for it
you can test for example with a raspberry pi. (RPi have serial console and you can got experience with connecting to serial console, rpi3 have a problem with serial console speed and you need to put rpi3 to a fixed CPU freq to serial console work correctly)
5) connect usb-serial-ttl to your laptop
with a terminal client you can connect to that serial port (in my ex. COM11)
you need a serial terminal client (hyper-terminal), my favorite is securecrt
if your terminal client can transfer files via Zmodem protocol you can send/receive files via serial console between laptop and CMU
to send from CMU to laptop type on CMU "sz filename"
to send from laptop to CMU type on CMU "rz" and select files on laptop
rz command NOT OVERWRITE existing files on CMU !!!
connect to CMU with over COMx with 115200,8,N,1 (baud rate,databits,parity,stop bits) without DTR/DSR, RTS/CTS, XON/XOFF
more info at http://mazda3revolution.com/forums/...id-auto-headunit-app-beta-62.html#post1735122
6) if you press ENTER the CMU will respond with a "cmu login:"
and you have a bash command-line
you can modify files, execute commands, transfer files via USB/SDCARD/Zmodem over serial
if your CMU is not "bricked" you will got a LOT of log messages, and you not see what you type and what respond you got
You can see an example in http://mazda3revolution.com/forums/...22458-aio-all-one-tweaks-404.html#post2075554
meanwhile I type "reboot" CMU show five lines and I see my command in different lines. BUT the command is in one logical line.
my hyper-terminal client can save to file the whole session and I can verify output of my commands in hyper-terminal own log file.
the best way is to copy/paste commands
*** AT YOUR OWN RISK ***
7) after you are connected with user/jci to cmu
prepare a usb with a directory "XX" on it
extract autorun.v2.zip in this XX dir on usb
modify / delete that you need/not need
put this usb to your CMU
wait 5 sec (to be mounted)
and copy/paste this commands in hyper-terminal for CMU
cp -r /tmp/mnt/sd?/XX/* /tmp/mnt/data_persist/dev/bin/
chmod +x /tmp/mnt/data_persist/dev/bin/autorun
after restart the scripts are running
rename attachment to 'autorun.v2.zip'