FT245R read problem

[tintin_99]

Hoi, I tried the example on the FTDI site ( loopback test ). all the function works fine except the read function and I read nothing. Do I need to physically attach something oir they are internally connected.?

How can I change the mode from loop to debug?

Any help really appercaited

[LaThoS]

Hi tintin_99,

I can't find the loopback test example on the FTDI site, but I imagine that is for the bidirectional serial port transceivers (eg FT232L chips) if it is a generic D2xx driver example.

According to the datasheet, the chip is internally connected to both the RX and TX buffers, but as you can only use one at a time, you will only read zeroes unless you have connected something to the inputs of the chip. In order to read from the FIFO buffer you will need to make #WR go from HIGH to LOW. This indicates to the chip that there is data ready on the port, and the chip should buffer it. The labview driver will only read back what has been buffered in hardware.

Let me know if this helps,