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I'm trying to get the FT245RL chip to work but am running into an issue where it is not successfully connecting to my computer.

I also have a separate device which also uses the FT245RL chip which connects correctly so I know that it is not an issue with my computer.

When my device is connected dmesg spits out

[1174250.282775] usb 2-1.3: new low-speed USB device number 108 using ehci-pci

[1174250.347768] usb 2-1.3: device descriptor read/64, error -32

[1174250.518754] usb 2-1.3: device descriptor read/64, error -32

[1174250.685755] usb 2-1.3: new low-speed USB device number 109 using ehci-pci

[1174250.750753] usb 2-1.3: device descriptor read/64, error -32

[1174250.919744] usb 2-1.3: device descriptor read/64, error -32

[1174251.085730] usb 2-1.3: new low-speed USB device number 110 using ehci-pci

[1174251.501718] usb 2-1.3: device not accepting address 110, error -32

[1174251.565708] usb 2-1.3: new low-speed USB device number 111 using ehci-pci

[1174251.981689] usb 2-1.3: device not accepting address 111, error -32

[1174251.981787] usb 2-1-port3: unable to enumerate USB device

[1174325.139540] usb 2-1.3: new low-speed USB device number 113 using ehci-pci

[1174356.370191] usb 2-1.3: new low-speed USB device number 114 using ehci-pci

[1174356.435191] usb 2-1.3: device descriptor read/64, error -32

When plugging in the working device (that wasn't designed by me) that uses the RT245RL it says that it is a full-speed USB device. I know that there is a program which you can use to write the manufacturer and serial number so maybe you can also select wether it's low speed or full speed?

From trying to research I see errors that are somewhat related to this are due from not having sufficient power going to the usb device. Maybe the low-speed issue is some fault with my power line.

I've tried continuity checking all the connections from my schematic to make sure everything is correct.

A schematic of my designs can be viewed at http://gyroninja.net/files/schematic.pdf

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2 Answers 2

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Those error messages you are getting are enumeration errors. They basically mean that something basic is missing. The USB data pairs are actually communicating but do not understand each other. I have a feeling that the DM and DP line is swapped but you say that you tested it, so here are a few questions:

  • Can you specify the exact type of USB-B connector you used and can you post a section of the PCB where it is connected and we can see the corresponding traces?
  • How long are these traces? Did you route them at a specific impedance?
  • What is the layer stackup of your PCB?`
  • Is the JTAG port for your controller working?
  • Can you confirm that you can measure the voltages VCC (5V), VCREF, VCCIO? What level do VCREF and VCCIO have?
  • Can you confirm you're using the RL package and not the RQ package?
  • When measuring with a multimeter on the DM and DP lines with USB unconnected, what's the level you're measuring on those lines?
  • Can you confirm there is no short between DM and DP?
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  • \$\begingroup\$ * I'm using this micro usb port. Here's pic related showing the usb port. * The traces are ~1.5mm. *No clue what that is, so no. *PCB stackup is 2 layers (copper) *Yes, I programmed my cpld earlier. *VCC: 1.379 VCCIO: 1.227 *What do you mean, there would be no power *There is no short \$\endgroup\$
    – gyroninja
    Commented May 7, 2017 at 10:40
  • \$\begingroup\$ Micro USB-B is NOT USB-B .. your connector in the schematic has 4 pins, wheras micro-usb-b has 5. In your connector, Pin 4 is ground - for Micro-USB-B GND would be 5. \$\endgroup\$
    – Tom L.
    Commented May 7, 2017 at 10:56
  • \$\begingroup\$ Your VCCIO doesn't match the CPLD OR the FT245RL, something is wrong with your voltage generation. VCREF appears to be wrong as well. I'm wondering: Either you're measuring wrong or you shouldn't have been able to program the CPLD \$\endgroup\$
    – Tom L.
    Commented May 7, 2017 at 11:00
  • \$\begingroup\$ In addition, it appears that all your pins are backward (at least if the unconnected pin is pin 5). Double check with the datasheet (right side of the datasheet shows the footprint from Top and labels Pins1 and 5) \$\endgroup\$
    – Tom L.
    Commented May 7, 2017 at 11:05
  • \$\begingroup\$ Thanks man. I just shorted pin 4 and 5 and it worked. :) \$\endgroup\$
    – gyroninja
    Commented May 7, 2017 at 11:30
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new low-speed USB device number 108 using

You have swapped D+ and D- somehow. The FT232RL is a full speed device, these are recognized on the host by pulling up D+ instead of D- for low speed.

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  • \$\begingroup\$ I tested continuity between D+ on my microusb and USBDP on the FT232RL and it was successful, so was D- and USBDM. These 2 connections are direct with nothing in between the port and the chip. For the port I used this. Perhaps the order of the pins on the usb is backwards? If viewed so the port is in the back left pin 1 is in the back and pin 5 would be the front. The pins are in the order of VCC, D-, D=, GND, NC. \$\endgroup\$
    – gyroninja
    Commented May 7, 2017 at 10:29

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