need serial console help. DVR

[korin1]

hi guys, im a pretty new to jtag\uart
right now i am trying to connect to a device via uart , but when opening putty to the COM i am seeing some gibberish,
my setup is like so , 3 cables to the uart on the board , 1 ground (black) 1 tx (white) 1 rx (green), which they are connected to rs232 which rs232 is connected to usb to pc, black (ground) goes to pin 5 , white (tx) goes to pin 2 , green (rx) goes to pin 3

hopefully one of u can help me out
thanks

 

[alastairstevenson]

Some possibilties to try:
Your PC serial interface cable / device (eg a USB to TTL serial convertor) is connecting to an RS232 interface on the DVR. These are quite different signal levels.

Your DVR TTL serial interface is connecting to a PC RS232 cable / device. These are quite different signal levels.

Your interfaces in the DVR and the serial cable / device are compatible, but the baud rate is incorrect. A common value is 115,200 with 8 bits, no parity.

You have the GND and RX swapped.

*edit* I can see from your last pic that it looks like you are connecting to a PC RS232 cable (the DB9 connector is the clue).
These use bipolar signals, +-3 to +-15 V signals
Common on a DVR are TTL level unipolar signals, 0- 3.3v
For this you'd need a TTL to serial convertor, eg a PL2303-based device.

 

[korin1]

Some possibilties to try:
\

hi, thanks alot for replying back

i did not quiet understand what u mean by saying "Your PC serial interface cable / device (eg a USB to TTL serial convertor) is connecting to an RS232 interface on the DVR. These are quite different signal levels."
what do i need to look for?

"Your interfaces in the DVR and the serial cable / device are compatible, but the baud rate is incorrect. A common value is 115,200 with 8 bits, no parity"
first think i've tested was 115200 with 8 bits
then i try all serial speeds , same result gebrish (different gebrish but still gebrish )

You have the GND and RX swapped
i dont think so, i've checked like 4 times

 

[alastairstevenson]

It does look like you have a PC RS232 interface connecting to a DVR TTL serial interface.
You can't do that - they use quite different signal levels and are not compatible.

If so, what you need on the PC is a 'Serial TTL to USB convertor'.
A common type which you will find in large numbers on eBay is a 'PL2303HX-based serial TTL to USB convertor'

 

[korin1]

It does look like you have a PC RS232 interface connecting to a DVR TTL serial interface.
You can't do that - they use quite different signal levels and are not compatible.

If so, what you need on the PC is a 'Serial TTL to USB convertor'.
A common type which you will find in large numbers on eBay is a 'PL2303HX-based serial TTL to USB convertor'

well i've watch this video (which apparently use rs232) i do have an rs232 connected to the pc via usb,
the TTL from the board is connect to this (to the back side of it to pin 2,3,5) and this (white one) rs232 female is connected to this > which is connected to the pc via usb.

do u think it might be the problem why it cant output regular text ?

 

[alastairstevenson]

do u think it might be the problem why it cant output regular text ?

Yes, as already explained.

 

[alastairstevenson]

It does look like you have a PC RS232 interface connecting to a DVR TTL serial interface.
You can't do that - they use quite different signal levels and are not compatible.

 

[korin1]

hey,

can this FTDI FT232RL USB works?
like one of these SparkFun FTDI Basic Breakout - 3.3V - DEV-09873 - SparkFun Electronics ?

or this
Pocket AVR Programmer - PGM-09825 - SparkFun Electronics

or this
RS232 Board SP3232 RS-232 UART TTL Transceiver Evaluation Development Module Kit | eBay

or this

CP2102 USB 2.0 to UART TTL 6PIN Module Serial Converter Adapter Blue+Silver LW | eBay

or this

USB to TTL Serial Cable - Debug / Console Cable for Raspberry Pi ID: 954 - $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits


(what im seeing is their is different chipset what i wounder is every one of these will work if pluged right into the mobo of the dvr)

 

[alastairstevenson]

Not all of the above are suitable, for both electrical and mechanical reasons.
As already explained, this type works well :

A common type which you will find in large numbers on eBay is a 'PL2303HX-based serial TTL to USB convertor'

416 matches here : PL2303HX | eBay

 

[korin1]

Not all of the above are suitable

hi,
im trying to learn i've guessed that some are not suitable, could u tell me which one is suitable and which one is not ?
that would also help other ppl to understand if their stuff doesn't work
thanks again !

 

[alastairstevenson]

can this FTDI FT232RL USB works?
like one of these SparkFun FTDI Basic Breakout - 3.3V - DEV-09873 - SparkFun Electronics ?

Requires a custom cable, bad reputation for driver quality and features.

or this
Pocket AVR Programmer - PGM-09825 - SparkFun Electronics

It's a programmer - not a TTL serial to USB convertor.

or this
RS232 Board SP3232 RS-232 UART TTL Transceiver Evaluation Development Module Kit | eBay

That might work - if you already have a genuine RS232 port on the PC, and the right form of connecting cable (modem, null modem).

or this

CP2102 USB 2.0 to UART TTL 6PIN Module Serial Converter Adapter Blue+Silver LW | eBay

That should work, according to the product specs. For me at least, the CP2102 drivers are an unknown quantity.

or this

USB to TTL Serial Cable - Debug / Console Cable for Raspberry Pi ID: 954 - $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits

That looks like a PL2303HX based product and should be OK.

 

[korin1]

Requires a custom cable, bad reputation for driver quality and features.

It's a programmer - not a TTL serial to USB convertor.

That might work - if you already have a genuine RS232 port on the PC, and the right form of connecting cable (modem, null modem).

That should work, according to the product specs. For me at least, the CP2102 drivers are an unknown quantity.

That looks like a PL2303HX based product and should be OK.

after month of waiting for the shipment
i got PL2303HX USB To RS232 TTL Auto Converter Module Converter Adapter For arduino | eBay

and
USB To RS232 TTL UART PL2303HX Auto Converter USB to COM Cable Adapter Module | eBay

and the result is the same..
like exactly the same.

what am i doing wrong ?

 

[korin1]

UPDATE
its working with USB To RS232 TTL UART PL2303HX Auto Converter USB to COM Cable Adapter Module | eBay
i just set it to 115200 bits and i was able to see
thanks alot

new question
i have a dvr SA-8200AHD-1(MM) which does not work properly nothing boot up, when powering it on it just beeping non stop.
when i connected my self to uart on the board on all bits possible (expect 115200) it shows me white question marks ???? and symbols one after another.
when changing the bit to 115200 it output me (while beeping . . .) blank spaces, not letters no nothing.
anyidea what could that be ? and how can i approch this problem ?