Brickpi docs update (input port 5) (ev3dev#167)

bmegli · dlech · commit 12d8bddc416d · 2016-06-06T18:11:57.000-05:00
* typo: providpe -&gt; provide

* Added docs for input 5 in BrickPi

* Added suggested changes for Input Port 5 on the BrickPi

* Better docs

Changed some wording
Added link to using-i2c-sensors
Clarified which sensors work on port 5, added link to supported sensors
table

* Improved readability

Added some sections etc

* Added back link to using-i2c-sensors
diff --git a/docs/ports/brickpi-in-port-5.md b/docs/ports/brickpi-in-port-5.md
@@ -0,0 +1,39 @@
+---
+title: Dexter Industries BrickPi Input Port 5
+---
+
+Input Port 5 on the BrickPi is physically wired to the I2C pins on the Raspberry Pi 
+and I2C is supported by i2c_bcm2708 kernel module. Port 5 is not present in BrickPi+. 
+
+Only `I2C/NXT` and `I2C/Other` sensors work on port 5. See `Connection` column 
+in [supported-sensors] to determine if particular sensor will work.
+
+## Using Sensors 
+
+For detailed I2C information see [using-i2c-sensors]. 
+
+For Input Port 5 you have to make sure that correct baudrate for the sensor is set 
+and load the driver manually. I2C/NXT sensors should work with slow 9600 baudrate 
+used originally in Mindstorms NXT.
+
+{% include icon.html type="warning" %}
+Some devices behave erratically if baudrate is changed while they are plugged in. 
+If needed unplug your sensor, change the baudrate and plug the sensor again.
+{: .alert .alert-warning}
+
+Example: Setting RaspberryPi I2C baudrate:
+
+    modprobe -r i2c_bcm2708 #remove module
+    modprobe i2c_bcm2708 baudrate=9600 #load module specifying baudrate
+
+
+Alternatively add `dtparam=i2c_baudrate=9600` to the end of `/boot/flash/config.txt` and reboot.
+
+Example: loading Microinfinity CruizCore XG1300L I2C/NXT driver manually:
+
+    echo mi-xg1300l 0x01 > /sys/bus/i2c/devices/i2c-1/new_device 
+
+Finally you can use the sensor through `/sys/class/lego-sensor/sensor#` interface.
+	
+[using-i2c-sensors]: /docs/sensors/using-i2c-sensors
+[supported-sensors]: /docs/sensors#supported-sensors
diff --git a/docs/ports/index.md b/docs/ports/index.md
@@ -10,6 +10,9 @@ sensor multiplexers fall into this category (see list below). Simple
 multiplexers that only support one connection type will not have a separate
 driver for the port.
 
+Input Port 5 on the BrickPi is physically wired to the I2C pins on the RaspberryPi.
+See [brickpi-in-port-5] for the details.
+
 Port drivers use the [lego-port class] to provide a common interface for
 interacting with individual ports. Follow the link for more information.
 
@@ -44,4 +47,5 @@ kernel.
 
 [sensors]: ../sensors
 [motors]: ../motors
-[lego-port class]: /docs/drivers/lego-port-class
+[brickpi-in-port-5]: /docs/ports/brickpi-in-port-5
+[lego-port class]: /docs/drivers/lego-port-class
diff --git a/docs/sensors/using-i2c-sensors.md b/docs/sensors/using-i2c-sensors.md
@@ -7,7 +7,7 @@ title: Using I2C Sensors
 
 The I2C standards only specify how data is sent from device to device. It does
 not specify the layout of the registers of a device. LEGO, however, has
-guidelines for 3rd party manufactures so that they can providpe sensors with
+guidelines for 3rd party manufactures so that they can provide sensors with
 a (fairly) uniform register layout.
 
 We call sensors that were designed following LEGO's guidelines **NXT/I2C**
