#qi-hardware IRC log for Friday, 2016-07-22

rohhm. anybody played with miniature (<3mm diameter) cmos cameras before?20:06
rohi got some for free and am wondering how to get them to talk to me.. it got i2c, some vout line and a '4mhz' labeled one. still not sure if i need to provide a clock in there or what20:07
whitequarkprobably has ntsc output20:42
rohwhitequark: maybe... any idea why 4mhz?21:07
rohntsc should eat 4.433 something i thought21:08
rohor 3.5something21:09
rohwell.. i found a 3.6864 oscillator in the misc parts box and hooked it up.. voila.. there is the i2c working somehow. a device on 0x36 which wasnt there before21:09
DocScrutinizer05hook your scope to vout21:57
DocScrutinizer05but I'm afraid you will need to initialize the thing via I2C21:58
DocScrutinizer05not exactly simple to guess or RE how to do that21:58
DocScrutinizer05wpwrak: http://bucket1.glanacion.com/anexos/fotos/30/medio-ambiente-2239330w640.gif  is deviation from long term average22:01
DocScrutinizer05no 'icy spot'22:01
rohhm. scoped it. i2c dumped it... and i guess my clock is too far off... anyhow.. the available brief-sheet says its not anything normal like regular video... 400x400 pixels says that quite directly.22:20
rohi fear i need to build some digizer extra for this22:31
DocScrutinizer05err, teh horizontal "pixels" (correctly lines) are irrelevant in a CVBS signal. And 400 lines vertical would be "normal" for NTSC, I.E should still show a picture when the frame rate is 45 to 65Hz22:45
DocScrutinizer05worst case use an old CRT TV, those are usually even more tolerant against out-of-specs  framerates, vertical resolution lines etc. Just the line frequency should be 15kHz to 16KHz22:49
DocScrutinizer05attaching a scope to vout you's easily see the line frequency, either it's TV ~16kHz, or VGA ~32kHz22:50
DocScrutinizer05problem would be progressive n H * 400 V for TV, you have interleave there and so a usual TV could only show cope with max ~700/2 lines per frame22:52
DocScrutinizer05progressive22:53
DocScrutinizer05VGA works also with 60Hz frame rate but 400 progressive, so the line frequency is twice as high22:53
DocScrutinizer05aka 640H*400Vprog@6022:55
DocScrutinizer05while PAL TV is nH*~512Vinterleave@5022:57
DocScrutinizer05oops sorry NTSC has 486V22:57
DocScrutinizer05and VGA 640*48022:58
DocScrutinizer05bottom line: as long as you see a semi-decent CVBS signal on vout, you'll most likely find a monitor (or TV) to sync and display that signal23:03
DocScrutinizer05nasty when vout has a serial digital signal though23:04
DocScrutinizer05dunno if https://en.wikipedia.org/wiki/Camera_Serial_Interface#CSI-1 would come with one non-differential line, for example23:08
DocScrutinizer05lane, not line23:16
DocScrutinizer05nope, even CSI-1 comes with differential lanes (and clock) only, at least CSI-1 actually has only one lane23:18
DocScrutinizer05http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=sn65lvds315&fileType=pdf23:19
DocScrutinizer05more convenient URL: http://www.ti.com/product/SN65LVDS31523:21
rohits not digital as far as i can guess. its a coax line and the sheet says analog out23:32
rohhttp://www.buyemp.com/product/ambu-ascope-3-5-0-2-223:32
rohthis is what i got ;)23:32
rohand i do NOT have this one to just 'sniff it' ;) http://www.buyemp.com/product/ambu-aview-monitor23:33
rohbecause the monitor gets reused, the camera-endoskop gets thrown away as medical trash usually23:35
rohmy plan is to recycle those for weird uses... maybe my friends with their beehives want some more sensors?23:38
DocScrutinizer05nice23:40
DocScrutinizer05yeah, coax and analog out are very good signs23:41
DocScrutinizer05I'd suggest to connect it to a cinch and plug it into a CVBS-in23:41
DocScrutinizer05;-)23:42
DocScrutinizer05could you mod one to wiretap the I2C and connect to a monitor device while sniffing?23:44
DocScrutinizer05since you will most likely need to confirure one or two dozen registers to make the critter behave23:45
rohi dont have access to a monitor. it sits in a sterile room which i dont have access to ;)23:47
rohwell.. next i'll get some better oscilator.. like 4mhz instead of 3.56someting23:48
DocScrutinizer05wore, not only you but also any laptops or whatever you would bring doesn't have access too23:48
DocScrutinizer05worse*23:48
rohatleast ive spoken a few bytes i2c or SCCB like omnivision calls it with something today23:48
rohSCCB seems to be i2c with no ack bits... which is kinda stupid but well...23:49
DocScrutinizer05meh23:49
DocScrutinizer05did a i2cdump?23:50
rohhttp://pastebin.com/UnZNpRzy23:50
DocScrutinizer05hmm 19 to 20 registers23:51
rohsome omnivision devices have an 16bit id register at address 0x300a23:51
DocScrutinizer05to 2523:51
rohso i just guessed that 69 30 is this.. at 0xa23:52
DocScrutinizer05:nod:23:53
DocScrutinizer05no manuf logo?23:53
rohand voila.. some google brought up http://www.ovt.com/products/sensor.php?id=49 , which is the first sensor ive looked at today which had some kind of analog out at all and is small enough to fit what i see as case (its 5.5mm total diameter and has a 2.2mm tool-shaft)23:54
rohhttp://www.ambu.de/deu/produkte/area_of_interests/anaesthesia/product/ambu%C2%AE_ascope%E2%84%A2_3_5-0-2-2-prod17261.aspx23:54
DocScrutinizer05:-D23:54
rohthis one23:54
DocScrutinizer05nah on the sensor, but you already found it23:55
DocScrutinizer05here you are 400*200@60, "full @30"23:57
rohwell.. thats my best guess so far. i am not sure at all... the numbers is just plain guessing from the i2cdump23:57
rohif that pcb in the handpiece would not have been labeled with silkscreen at the solderpads for the cable from the camera and to the monitor...   i would still not have power on it.23:58
rohthe 2 leds in the head get their own vcc and seem to like 20mA at 6.0-6.1V just fine... and my 'doctor friend' who uses these on a daily basis gave me his best guess when testing out different currents about how bright its on the original device23:59
--- Sat Jul 23 201600:00

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