Here is a picture of the module I am trying to get the right pinout to this module from a Canon MX492. I would like to know which one is goes to red, black, green and white for a usb connector. I don't have the whole printer to test what goes where and I'm fairly new to the whole hardware hacking thing. This has eight pins on a ribbon cable. I would like to use it for a RPi. All I know is it is possibly a USB module.

Edit: enter image description here

Edit: Chip markings. Marvell

88W8782U-NAP2 P14V750A2JW 1436 B0P TV C005

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  • \$\begingroup\$ Maybe you'd like to try again with that 2nd pic, or at least transcribe all of the markings... \$\endgroup\$ – brhans Nov 11 '17 at 18:31
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    \$\begingroup\$ Considering the cost in connectors, resistors and cabling of converting this to a device that you can connect to your pi, if that even is possible: just go and buy a WiFi dongle \$\endgroup\$ – Marcus Müller Nov 11 '17 at 18:36
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    \$\begingroup\$ I am good at soldering and buying a WiFi dongle defeats the purpose of repurposing items. I'm doing this and lots of others to save money and learn new things. I have done stuff like this with laptop webcams and other items. This item is a bit of a challenge for me. (Just makes me want to try that much harder) \$\endgroup\$ – Little Big MAC Nov 11 '17 at 18:42
  • \$\begingroup\$ The ground pin is connected to the ground plane and packaging. You may be able to get the power voltage from the datasheet, but USB cables only provide 5V, an embedded controller may need a lower voltage. power supply has wider traces and is connected to decoupling capacitors. For the USB signal pins, you can try all combinations until it works, you won't break anything swapping the wires. \$\endgroup\$ – TEMLIB Nov 11 '17 at 18:46
  • \$\begingroup\$ It looks like the chip itself is 3v3. Even if it is 3v3 for the module itself the RPi has 3v3 out from the board. Not sure if it has the amperage but it has the power. I still think it is 5vdc. \$\endgroup\$ – Little Big MAC Nov 11 '17 at 18:54

So - the pages of the datasheet you're posted don't show any USB interface pins ... but:
- this Marvell Databrief says is has a USB 2.0 interface
- this Panasonic module which uses the Marvell 88W8782 indicates that it has a USB option, and that the USB D-/D+ pins are shared with SD_CMD & SD_DAT[0] respectively.

USB D+ (green) -> pin 53 (SD_DAT[0])
USB D- (white) -> pin 52 (SD_CMD)

I don't see anything on that board which looks like a regulator, and that IC appears to run on 3.3V, so you'll need a separate 3.3V regulator (because your RPi can't source enough current on the 3.3V rail) and feed it to pins 1 & 2.
Do not connect the USB 5V (red) to anything other than the input to that regulator or the smoke will come out somewhere...
You can probably hook Ground/0V (USB black) to anything connected to the shielding can.

Note that the pin numbers I'm referring are the IC pins, not the connector.
You could probably beep those through to the IC with a continuity tester.

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  • \$\begingroup\$ The rpi 3.3V cannot supply the current that this module needs. You need a separate 5 to 3.3V regulator or you can fry the onboard 3.3V reg \$\endgroup\$ – Passerby Nov 12 '17 at 4:12
  • \$\begingroup\$ Yeah I was just reading about that too. 50mA but it said that also if no hdmi and no ethernet you can pull maybe 100mA. They said it would "blow" the polyfuse. \$\endgroup\$ – Little Big MAC Nov 12 '17 at 4:24
  • \$\begingroup\$ Thx @Passerby - I'm not familiar with the RPi - adjusted my answer accordingly. \$\endgroup\$ – brhans Nov 12 '17 at 12:55

I have found that if you look at where the ribbon comes out, where the yellow triangle is pointing to pin 1 of the ribbon it goes as follows. From what I found both pin 1 and 8 have a resistor between it and the chip.

1 - GPIO[1] the paper says it is LED Out.
2 - Ground
3 - Goes to Pin 53 on the chip.
4 - Goes to Pin 52 on the chip.
5 - Ground
6 - Ground
7 - + 3.3VDC In
8 - PDn on Chip is in the picture.

PDn pin description

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