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Hi I'm trying to build my own custom arduino board. The FT232rl doesn't want to accept the address given to it. I've wired in all the gnd and vcc wires. Including the gnd wire for the usb port. I'm getting this error in my dmesg

[23289.780022] usb 4-3: new full speed USB device using ohci_hcd and address 75
[23290.201047] usb 4-3: device not accepting address 75, error -62
[23290.370021] usb 4-3: new full speed USB device using ohci_hcd and address 76
[23290.790020] usb 4-3: device not accepting address 76, error -62
[23290.790030] hub 4-0:1.0: unable to enumerate USB device on port 3

I've wired pin 2 of the usb port (D-) to pin16 and pin 3 to pin 15. Am I not correct in saying the FT232RL has a build in usb transceiver so therefore it should be able to register as full speed device by itself? I have a ttl converter using the same chip that registers as soon as I plug it in.

According to my scope the chip is oscillating at 38MHZ so I can only assume I didn't damage it when I was soldering it. I have to admit this is the first ssop I've soldered.enter image description here

Wired the same except I've not wired in the tx/rx. I've also wired the test pin to gnd because the DS told me to. Windows detects as unknown device but in device manage it said it's been disabled because the device reported issues.

http://docs-europe.electrocomponents.com/webdocs/0aa3/0900766b80aa32f9.pdf The same ds sheet on rs website which is where O brought the chip from

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    \$\begingroup\$ what bypassing do you have on 5V line? FTDI recommends 0.1 + 0.1 + 4.7uF \$\endgroup\$ – markrages Jun 24 '11 at 21:25
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    \$\begingroup\$ for that matter, since you are not bus-powering, what is the source of 5V? \$\endgroup\$ – markrages Jun 24 '11 at 22:19
  • \$\begingroup\$ 38MHz? Where are you measuring that? is it a typo for 48MHz? \$\endgroup\$ – Martin Thompson Sep 7 '11 at 12:30
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I've heard you need to wire the TEST pin down to GND. Otherwise you leave the Device in test mode and nothing works.

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  • \$\begingroup\$ Spot on: From the datasheet pg7 "Must be tied to GND for normal operation, otherwise the device will appear to fail." \$\endgroup\$ – Martin Thompson Sep 7 '11 at 15:52
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Your J3 pin numbering is the opposite to that specified for a USB connector - check that it all maps out correctly on the PCB (I'd be surprised if it did anything remotely sensible with the connector backwards, but you never know!)

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Have you used another FT232 with that machine? I believe you need to have a kernel module installed for it to function properly.. If you could test on another that you're more sure should work, then that helps rule our your machine's config.

If you're unsure about how to use that chip still, please be sure you're looking at the correct datasheet for it.

Have fun! Sounds cool.

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  • \$\begingroup\$ Yes I have. I was once hacking a netgear router with a ttl convertor using the same chip. Am positive it's the correct ds because it's from FTDI for the FT232R range. 232RL for the 28pin SSOP version \$\endgroup\$ – Ageis Jun 24 '11 at 19:36
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    \$\begingroup\$ Would you please link your datasheet and a diagram of how you've connected this up? I'm not sure I can help you otherwise - may not be able to anyway.. But I'll try. \$\endgroup\$ – James T Snell Jun 24 '11 at 19:42

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