Thanks for the response. It's a shame that the RS-232 is 1.8V - I was hoping to connect directly to my smart card reader which is probably way more than that. One would think that, since the Palo is a development board, they would have driver circuit/chips to allow connecting to higher voltages (as is common in most serial devices). Thanks for offering to provide pointers, I will certainly appreciate any help you can give me wrt connecting my reader.
Ah, I was not aware of the -8 switch. Glad you came right.
No, I can't say I know how to remove a serial port from being the console. My guess would be that you might have to change /etc/inittab or /etc/ttytab or something similar (I don't have access to my Overo right now, so I can't have a look right away). Sorry, I am sure this is not that useful at all.
On 26 May 2009, at 17:57, Daniel Riegel wrote:
Yes, we are using the Rx/Tx connectors on the Palo43. We hooked up both, not sure which I am currently using, but the other one seemed to interfere with console output, so we disconnected it. The one my signals come out from is /dev/ttyS0. The voltage levels coming out of the Palo43 are 1.8 V. We had to make a level shifter circuit to boost the signal to 3.3 V on the way to our radio, and reduce the signal to 1.8 V on the way to the Palo43. If you'd like some pointers on how to put together that circuit, I can ask our electrical engineer. BTW, since I sent the last message, I discovered that the -8 flag fixed most of the serial problems I was having, so the new agetty command is
agetty -8 19200 ttyS0
There are still some odd characters at the beginning of some lines I'd love to share findings on the serial interfacing front. Do you understand how to change a serial output from being a console to being usable for device I/O?