Configuring ext signals - Revision history

HelenF: Moved content to EXT Connector

2014-06-06T20:27:37Z

Moved content to EXT Connector

2014-05-30T14:30:16Z

‎UART: note about PySerial

2014-05-28T00:20:47Z

‎GPIOs: shell script is slow

2014-05-27T21:18:58Z

‎Power supply: expanded voltage warning

2014-05-27T16:35:36Z

Expanded UART and PWM

2014-05-25T13:22:12Z

‎Pad Configuration Register: Clarify PULLUDENABLE.

2014-05-25T13:18:38Z

‎GPIOs: Expanded.

2014-05-25T12:56:15Z

‎Setup: Removed hashes.

2014-05-24T20:35:14Z

Expanded: Pin functions (mux)

2012-11-19T14:28:29Z

update

← Older revision		Revision as of 14:30, 30 May 2014
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	See the [http://www.cmrr.umn.edu/~strupp/serial.html Serial Programming Guide for POSIX Operating Systems].		See the [http://www.cmrr.umn.edu/~strupp/serial.html Serial Programming Guide for POSIX Operating Systems].
		+
		+	[http://pyserial.sourceforge.net/shortintro.html PySerial] works for configuring and using the ports.

	==UART3==		==UART3==

@@ Line 208: / Line 208: @@
 echo NNN > /sys/class/gpio/unexport
 </source>
 =UART=

@@ Line 166: / Line 166: @@
 .5V, 1.8V, 2.5V, 2.8V and 3.0V, with 2.8V as default.
-'''warning''': at the time of this writing, both bootloaders (xload and u-boot) set this to 2.8V unconditionally, so don't rely on this providing other voltages during reboot until you patch both bootloaders.
+'''Warning''': at the time of this writing, both bootloaders (xload and u-boot) set this to 2.8V unconditionally, so don't rely on this providing other voltages during reboot until you patch both bootloaders. The digital I/O pins use 1.8V logic and must not be connected to the 2.8V from the power pin!
 =GPIOs=

@@ Line 209: / Line 209: @@
 </source>
-=UART3=
+=UART=
 On older firmwares, kernel messages are directed there. SuperZaxxon or later have that disabled.
 On all firmwares released so far terminal with a shell is attached to UART3. The port runs at 115200 8N1 baud rate.
 ==Disabling kernel messages==
 To disable kernel mesages, you need to edit kernel boot arguments. Probably easiest way to do it is to create autoboot.txt and place on root directory of a card in slot1 with this content:
 <source lang="bash">
@@ Line 219: / Line 232: @@
 </source>
 Alternatives are using u-boot environment (configure through USB or UART3 serial before system boots up) or patching and reflashing u-boot itself.
 ==Disabling attached terminal==
 For this you need to edit /etc/inittab on pandora rootfs and comment out these lines:
 <source lang="bash">
 #S0:2345:once:/sbin/getty 115200 ttyS0
 #O2:2345:once:/sbin/getty 115200 ttyO2
 </source>

@@ Line 66: / Line 66: @@
 | 3
 | PULLUDENABLE
-| 0: pull not active. 1: pull active if pin not configured as output.
+| 0: pull not active. 1: pull active when pin direction is configured as input.
 |-
 | 2,1,0

@@ Line 170: / Line 170: @@
 =GPIOs=
 Can be controlled using GPIO sysfs class device, as described in beagleboard tutorials [http://bbfordummies.blogspot.com/2009/07/1.html here].
 =UART3=

@@ Line 8: / Line 8: @@
 <source lang="bash">
-# mkdir /debug
+mkdir /debug
-# mount -t debugfs none /debug
+mount -t debugfs none /debug
 </source>

@@ Line 1: / Line 1: @@
 =Pin functions (mux)=
-==Changing pin functions under 3.2 kernel==
+By default the UART2 pins are set up as GPIOs, and UART3 is set up as an UART. The following describes how to change pin functions under a 3.2 kernel.
-Described in the [http://boards.openpandora.org/index.php?/topic/4497-talking-to-the-gpios-on-the-ext-connector/page__st__40#entry195457 following forum post]
 =Power supply=