I have codes in app designer of MATLAB, through the codes I can send data to FT232 board serial, then the LED is lighted successfully by the circuit I connected.
And I try to design the circuit by connecting some pins uesd in the above successful experiments, but the new circuit does not work. I made PCB and connect it to PC, but PC can not recognize this serial even though I install the driver.
Thank you for your answer!
However, I still have some questions.
1.I remove the connection from 3V3out to VCCIO, and connect VCCIO and VCC, but PC can not recognize the serial, either.
2.I connected the LED backwards in my test as figure1 above and it does not work. However, the original direction can make it work, so I feel strange.
3.I read the FT232 data sheet and know the function of CBUS0 and CBUS1. However, in my test circuit as figure 1, I used TXD to drive the LED and it can work. Therefore, I wonder why it can not work in figure 3.
Looking forward to your reply. Thank you again!
I can't see how you have things connected in figure 1.
Maybe you may have an error in your layout or PCB assembly.
Maybe you have damaged the IC.
The values of the resistors and capacitors may be wrong.
Maybe your USB cable is bad or you are using the wrong type of cable.
I'm not there with you so I can't check these things. You must check and tell me.
I delete the connection from shield to ground, but it does not work. The ID pin is grounded in some examples I saw. Could you please tell me why it shoule not be connected?
Thank you again for you kindness! Looking forward to your reply.
It is there for devices to know which end of an OTG cable it is connected to. If you ground it and you use the wrong cable you could burn out your computer and/or board.
What is the value of R1?
What is the forward voltage of the LED?
Why didn't you just copy the schematic of the FT232 board you already have??
The usb is different because I can not find the same usb as which used in the schematic of the FT232 board in she shop I made the PCB board.
I also change the cable, but there is also no use. Maybe the question is caused by USB. I will delete the connection of ID pin and ground.
Thank you for your reply!
As I pointed out 330 is too low. The TX pin can only source a few milliamps. Besides you should use the CBUS pins for the LEDs, that is why they are there.
actually I designed my schematic refer to the schematic of the FT232 board, using this part.
Then there must be a bad solder connection or a broken or shorted PCB trace. I can't tell without actually seeing the board.
Dear Jim-p,
Thank you for your answer! I follow your advice and redraw the schematic, then make the PCB board again, so it takes two weeks.
I use resister of 2kΩ, and delete the connection of ID pin and ground. I also use two methods, one is use TXD of FT232 to drive LED, the other is use CBUS0 to drive LED. However, both of their PCB boards still can not be recognized by PC.
It really trouble me. Could you please help me find the mistakes?
Here are my schematic and PCB. The PCB board up and down are separated.
