Camera module serial communication challenge - Page 1
Forum section: electronics / projects

author: Red Dwarf
author_rank: Newbie
timestamp: December 21, 2014, 07:44:35 am
content: GdayI have fewSAMSUNG SCM-2271Pmodules from blown up PTZ cameras.Those have zoom lens, the module is controlled via RS232C in TTL.I happen to also have USB/RS232TTL modules from eBay.I'm little inexperienced in this territory, how would you start talking to the camera from a PC?Some technical:the module has 6pin connector -VideoGND / Video / GND / +12 / TXD / RXD (gives great picture)the Tx pin pulls up tp 3V3 on powerup, rx stays on 0Vthe whole PTZ cameras usually have large OSD menus, usually controlled via RS485 Pelco protocol - there are commands for 'open menu(save preset95)', 'close menu(save preset94)', select(iris open), back(iris close), up, dn, left, rightI would imagine the OSD is in the mainboard that blew up, however the module itself should listen for zoom commands.I'd like to be able to control the zoom on this module, just for fun.any ideas..?

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 21, 2014, 07:55:02 am
content: Not clear what you mean by "the mainboard that blew up"?Do you mean something in the camera module blew up?Or do you mean something in the pan/tilt unit the camera came out of?The specs for the camera module claim there is an OSD menu in the camera itself.The specs also say that it wants RS-232 serial at TTL levels.What are the levels coming out of your USB/RS232TTL modules?Be careful to not connect the legacy +/- 15V RS-232 to that camera.The only question is how it detects the baud rate?Can you get the full manual for the camera module?It should show all the commands and protocol, etc.There are a great many more controls than just the zoom, of course.

author: Red Dwarf
author_rank: Newbie
timestamp: December 21, 2014, 08:19:59 am
content: Thanks Richard.The whole PTZ camera consists of this video module (that has the zoom lens), then motherboard with some RS485 receiver and stepper motor drivers to pan & tilt this module.In complete functioning PTZ camera, there is a large multi-level menu with many settings for the pan&tilt functionality so I guess they are not in the camera module itself(it does only zoom)I was unable to get any other info then in the link. It saysExternal control RS-232C TTL Level?2400.4800.9600.19200.38400.57600.115200bps?and that's all I've got.I'm just hooking up the camera onto my TTL serial convertor:http://www.ebay.com/itm/161103531292?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AITI want to try Putty on various baud rates, hooked up the Rx to Tx and vice versa plus the GND pin.I have no idea if it's going to do anything.

author: Red Dwarf
author_rank: Newbie
timestamp: December 21, 2014, 09:53:46 am
content: OK I tried PuTTY on COM4 serial (Sillicon Labs CP210x USB to UART bridge)speed: anydata bits 8stop bits 1parity noneflow ctrl XON/XOFFconnected TX on PC to RX on cameraconnected RX on PC to TX on cameraI opened many sessions, tried all speed combinations, disconnected RX on PC, rebooted camera, rebooted camera while attempting to connect, tried another serial convertor..etcI get only solid cursor in the serial session, obviously I'm not talking to it.Also it's strange to me that the rx/tx lights on the convertor did not flash once.any ideasanyone needs hi-res cam module with big lens

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 21, 2014, 01:49:21 pm
content: But you aren't really using ANY "flow ctrl" at all. Turn that off.You can also test the serial gadget by "loop-back", connect the RX back to the TX and confirm that you are getting your keystrokes echoed back to the window.Look around on the camera module for (perhaps Sony) model numbers that might be clues what to Google to find the protocol information.

author: Red Dwarf
author_rank: Newbie
timestamp: December 22, 2014, 07:32:11 am
content: great info, cheers.I turned off the flow control and tried all speeds again.The adapter does echo through loopback....nothing.The cameras were hit by lightning through the utp telemetry wire. They were all dead but I decided to keep them from landfill.Jan de ZL2CZE

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 22, 2014, 07:40:03 am
content: I would love to play with one, but it probably costs more to ship than it is worth.

author: Red Dwarf
author_rank: Newbie
timestamp: December 22, 2014, 08:05:16 am
content: pm me and get one for xmas

author: Jeroen3
author_rank: Super Contributor
timestamp: December 22, 2014, 09:14:21 am
content: Quote from: Red Dwarf on December 21, 2014, 09:53:46 amGo and get Hterm. It also shows bad data.http://www.der-hammer.info/terminal/If it says "2400.4800.9600.19200.38400.57600.115200bps" it might have auto-baud. Or it will start on any default one selected by jumpers, the slowest or the common 9600 8N1.You have only about 400 possible ways to communicate, so you'll be of the streets this holiday.

author: htassell
author_rank: Unknown
timestamp: December 22, 2014, 09:34:26 am
content: I couldn't find the manual for that exact module, but here's a link for the technical manual (with command set) for a similar Samsung SCM camera modulehttp://www.vanthinkcctv.com/UploadFiles/soft/SCM-2370%20Technica%20Manul_V1.0.pdfHope its of some help

author: Red Dwarf
author_rank: Newbie
timestamp: December 23, 2014, 09:03:45 am
content: Quote from: Jeroen3 on December 22, 2014, 09:14:21 amBrilliant.This is nice piece of software, I just need to learn how to output the right data. There is a little hope the camera is on "38400bps default" as per the pdf from htassell so I might be finished with it this yearExcuse my ignorance but how do I type A3h 04h 00h 00h 00h FFh AFh command in that program, what format is this and what the 'h' stands for?I was trying to google different serial data commands but it's hard to find answer to what I'm looking for.

author: Red Dwarf
author_rank: Newbie
timestamp: December 23, 2014, 09:09:47 am
content: Quote from: htassell on December 22, 2014, 09:34:26 amWell that is a big leap from yesterday, thanks mate!Looking at page 9, there could be the option to attach a keyboard; the first 5 pins are surely k(keyboard) s(select) r(right) l(left) d(down) u(up)As soon I have the time I'll definitely give it a go - that would be a winner.

author: Jeroen3
author_rank: Super Contributor
timestamp: December 23, 2014, 11:39:49 am
content: Put the "input control" drop-down to HEX instead of ASC.Does it accept keyboard scan codes? I've never seen that before.