Seven months after placing my order I finally received a SLG4DVKDIP. Unfortunately, it does not work: a blue LED lights up but otherwise the board behaves as if not being connected to the host's USB port at all, dmesg (Linux) is completely silent, that is, even the D+ pull up does not work. What shall I do?
Could you try another PC with a different operating system to double-check if the board is damaged?
I tried 3 computers (2 Linux, 1 Windows) with 3 USB ports (mixture of USB 2 and USB 3) each and 3 different USB cables. Same behavior for all 27 combinations: blue LED, nothing else.
BTW, the board version is v.1.0.3, the date code is probably 2305.
Measuring at the host end of a USB cable, GND, VBUS, D+, and D- are connected to somewhere on the SLG4DVKDIP board, there are no shorts.
thank you for the detailed investigation. I have to check with the HW team about your issue. Most likely, if the board is damaged, it should be replaced.
Could you show how GPAK designer looks when you enter the Debug, I would like to see the Debugging Controls widget.
The USB host adapter does not electrically see the SLG4DVKADV, therefore the OS does not see the SLG4DVKADV, therefore GreenPAK Designer does not see the SLG4DVKADV. The Debugging Controls widget looks exactly the same with and without the SLG4DVKADV connected.
Interestingly, the power LED (which is red according to the pictures in the manual) is off. The blue LED is labeled "status". The DC-DC converter seems to work, I measure 7.6 V. On the 5.3 V rail I measure 5.6 V, which is too high. No oscillation can be measured on the crystal with a 100:1 probe. Unfortunately, there's no schematic for the SLG4DVKDIP, so I have to use the SLG4DVKADV schematic...
A USB power meter measures 0.00 A, ie, less than 10 mA. The SLG4DVKADV creates the 5.3 V rail from the 5.6 V rail with a Schottky diode. Both facts combined could explain why the 5.3 V rail is too high (no voltage drop across the diode due to too little current). I guess the MCU is shot or idling along (using its internal oscillator) due to not being programmed.
Working from the SLG4DVKADV schematic and the observed behavior, I assume that the STATUS LED on the SLG4DVKDIP corresponds with the P1_STATUS LED on the SLG4DVKADV and indicates that VBUS is high enough. The other LEDs on the SLG4DVKADV are controlled by the MCU, so is probably the POWER LED of the SLG4DVKDIP.