Reply To: I cannot conect to CHR Serial Interface
The Serial Interface will attempt to send the command 3 times before giving up. If the UM7 is receiving the packet (as evidenced by a behavior change), then somehow the acknowledgement packets are not making it to the serial port. The only condition in which I’ve seen this happen is if the bus is swamped with too much data (because the baud rate was dropped or lots of data transmission is turned on) or if the serial conversion hardware can’t keep up.
An FTDI board should be able to keep up if it is functioning properly and designed correctly. We can’t vouch for other hardware, but we do know that our serial expansion works well: http://www.chrobotics.com/shop/usb-expansion-board