I am using the ALFAT in I2C mode and I need to detect when a PC is connected to the USB port. I understood that this could be seen with the U1 Connect line. I am stepping through my code and the manual says that when the media is initialized the line will be raised and then it will lower when a PC connects. Is this the way this works? The schematics don’t show a pull up resistor so I have a 10k resistor between the ALFAT and my microcontroller. Could that be why I don’t see anything changing? Thanks.
@ Makares -
The document might not correct with that description.
U1_CONNECT is only high when ALFAT is connected to PC successfully , other than that it will be low.
“ALFAT is connected to PC successfully” means:
- ALFAT is in SD reader mode (by “I D:H” command)
- ALFAT is connected to PC (U1 port)
- Usually a pop up “New Media” will be shown on the PC’s screen.
Alright. So I am connecting with the “I D:” command without the “H” as I did not want to populate that on my board. Will the U1 Connect line not work without the high-speed chip. I do get the “new device” message on my machine. At any rate I was hoping to use this line as an indicator that a PC was out there. If that is not possible then I will have to come up with a different plan.
@ Makares -
No, that pin should turn on in both cases.
You have to remove the HS_PHY chip, it will work, I just tried it.