I've been trying to connect my Pi to my Mac using a USB-TTL cable. I followed this tutorial. On the terminal I get nothing when the Pi connects (not even sure if it connects at all). I've tried everything:
- checked the connection with the GPIO pins
- launched the terminal well after the Pi booted
- tried CoolTerm: it seems to connect but the screen is blank (just like with the terminal)
- tried two different SD cards
- tried two different laptops (Mavericks and Snow Leo
- checked the driver on both laptops: when the TTL cable is connected it appears in both the terminal (ls /dev/tty.*) and in the System Profiler
- tried both 'screen /dev/tty.usbserial 115200' and the screen /dev/tty.PL2303-000014FA 115200
- tried replacing 'tty' with 'cu'
- remove WIFI dongle
Still no luck. What did I do wrong?
Update: hooked up a logic analyzer to the TX pin and got no signal during booting and when doing a serial test. Is there any reason why the UART wouldn't work?
Update2: disabled the boot messages and the login using this tutorial and hoked up an arduino to the pi (important: the Pi's GND must be connected to the Arduino's GND pin). The arduino sends a single character and echos everything back. Once I fired up minicom and with the right Baud-rate, I could see the characters coming in and all the typed characters being echoed back. So the UART works but it won't send any boot messages or allow login with a console.