Monday, December 28, 2020

An Italian VOM: Chinaglia "Cortina Major"

I own one of those superb VOMs.

It features 40kOhm/Volt both in CC and AC, not a so common feature.

Googling around I realized that the schematic diagram is not available on the net.

Here it is:

Chinaglia Cortina Major
Please note the galvanometer specs: 17.5uA FS!!

Enjoy.

Emanuele.

Thursday, April 2, 2020

how to recover a ck77 3.3V camera module from a scrap PC

Got a ck77 94v-0 3.3V (model 5SF001N2F) camera module out of a scrap ASUS K550V. It shows a Realtek RTS5806 chip on board.



ck77 94v-0 3.3V (model 5SF001N2F)
ck77 94v-0 3.3V (model 5SF001N2F)


There are plenty of instructables posts and videos out there teaching how to recover webcams out of scrap PC.
Unfortunately none of them covers the webcam module I have got so I had to find myself the pinout needed to successfully connect it to a USB port.

Here are my findings:


..and this is the prototype patch PCB to connect the module to a USB cable.






It works!
As you can see, to drop the USB 5Volt power voltage to the 3.3Volts required by the module I've chosen the quick and dirty way: two signal diodes connected in series. They work fine but if you want to be more professional think of a 3.3Volts LDO (eg. LM1117).

If the module is not correctly detected by your PC try swapping the two USB wires. Here is the detection sequence produced by my Linux PC:
Apr  2 16:04:52 emahome kernel: [24432.594683] usb 1-3.4: new high-speed USB device number 8 using xhci_hcd
Apr  2 16:04:52 emahome kernel: [24432.787321] usb 1-3.4: New USB device found, idVendor=0bda, idProduct=57de
Apr  2 16:04:52 emahome kernel: [24432.787323] usb 1-3.4: New USB device strings: Mfr=3, Product=1, SerialNumber=2
Apr  2 16:04:52 emahome kernel: [24432.787324] usb 1-3.4: Product: USB2.0 VGA UVC WebCam
Apr  2 16:04:52 emahome kernel: [24432.787325] usb 1-3.4: Manufacturer: 04081-0005570016271000832
Apr  2 16:04:52 emahome kernel: [24432.787326] usb 1-3.4: SerialNumber: 200901010001
Apr  2 16:04:52 emahome kernel: [24432.789595] uvcvideo: Found UVC 1.00 device USB2.0 VGA UVC WebCam (0bda:57de)
Apr  2 16:04:52 emahome mtp-probe: checking bus 1, device 8: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4"
Apr  2 16:04:52 emahome mtp-probe: bus: 1, device: 8 was not an MTP device
Apr  2 16:04:52 emahome kernel: [24432.790594] uvcvideo 1-3.4:1.0: Entity type for entity Extension 4 was not initialized!
Apr  2 16:04:52 emahome kernel: [24432.790595] uvcvideo 1-3.4:1.0: Entity type for entity Processing 2 was not initialized!
Apr  2 16:04:52 emahome kernel: [24432.790596] uvcvideo 1-3.4:1.0: Entity type for entity Camera 1 was not initialized!
Apr  2 16:04:52 emahome kernel: [24432.790676] input: USB2.0 VGA UVC WebCam: USB2.0 V as /devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.0/input/input19
Apr  2 16:04:53 emahome upowerd[2886]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.1
Apr  2 16:04:53 emahome upowerd[2886]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4/1-3.4:1.0
Apr  2 16:04:53 emahome upowerd[2886]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-3/1-3.4



Enjoy your 0 bucks webcam!