RS485/GPIO Shield for Raspberry Pi - Revision history

Qian.zhang at 07:28, 16 September 2014

2014-09-16T07:28:46Z

Qian.zhang: /* Tutorial */

2014-09-16T07:27:33Z

‎Tutorial

Alvin at 04:57, 13 March 2014

2014-03-13T04:57:59Z

Alvin at 01:43, 13 March 2014

2014-03-13T01:43:28Z

Alvin at 09:37, 20 February 2014

2014-02-20T09:37:26Z

Jingfeng at 18:07, 7 November 2013

2013-11-07T18:07:17Z

Jingfeng: Created page with " ==Description== This is a shield to add a RS232 level shift to the UART of Raspberry Pi. Moreover, it also breakout the rest headers for easy access. ==Tutorial== T..."

2013-11-07T18:06:36Z

Created page with " ==Description== This is a shield to add a RS232 level shift to the UART of Raspberry Pi. Moreover, it also breakout the rest headers for easy access. ==Tutorial== T..."

New page

==Description==

This is a shield to add a RS232 level shift to the UART of Raspberry Pi. Moreover, it also breakout the rest headers for easy access.

==Tutorial==

The UART on Raspberry Pi is on P1 and shown below:

[[File:RPI UART.png]]

The UART is /dev/ttyAMAO, it defaults to output system log. But if user wants to use this UART to connect to other modules through UART, for example, GPS module, we need to change the configuration.

The detailed steps are as following:

We need to modify two files: /boot/cmdline.txt and /etc/inittab.

Modify /boot/cmdline.txt:

Replace the original content:

dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait

With:

dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait

Modify /etc/inittab:

Comment out the last line of /etc/inittab. To comment out, it simply addess a '#'.

$ sudo vi /etc/inittab
#T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100

Save the changes, and reboot. We will get an UART with baud rate of 115200.

@@ Line 1: / Line 1: @@
-==Description==
 This is a shield to add a RS485 level shift to the UART of Raspberry Pi. Moreover, it also breakout the rest headers for easy access.
-==Schematic==
+==Schematics==
-[[File:RS485GPIO Shield for RPI.jpg]]
+[https://s3.amazonaws.com/linksprite/Shields/RS485_RPI/RS485+shield+for+RPi.pdf Schematic]
 ==Tutorial==
@@ Line 56: / Line 54: @@
 *[http://learn.linksprite.com/raspberry-pi/shield/user-tips-of-rs485-shield-for-rpi/ User Guide of RS485 Shield for Raspberry Pi]
 ==How to buy==
 Here to buy RS485/GPIO Shield for Raspberry Pi on [http://store.linksprite.com/rs485-gpio-shield-for-raspberry-pi/ store]

← Older revision		Revision as of 07:27, 16 September 2014
Line 52:		Line 52:

	Save the changes, and reboot. We will get an UART with baud rate of 115200.		Save the changes, and reboot. We will get an UART with baud rate of 115200.
		+
		+	== Resources ==
		+
		+	*[http://learn.linksprite.com/raspberry-pi/shield/user-tips-of-rs485-shield-for-rpi/ User Guide of RS485 Shield for Raspberry Pi]

	==Download==		==Download==

@@ Line 52: / Line 52: @@
 Save the changes, and reboot. We will get an UART with baud rate of 115200.
 ==How to buy==
 Here to buy RS485/GPIO Shield for Raspberry Pi on [http://store.linksprite.com/rs485-gpio-shield-for-raspberry-pi/ store]

← Older revision		Revision as of 01:43, 13 March 2014
Line 4:		Line 4:

	This is a shield to add a RS485 level shift to the UART of Raspberry Pi. Moreover, it also breakout the rest headers for easy access.		This is a shield to add a RS485 level shift to the UART of Raspberry Pi. Moreover, it also breakout the rest headers for easy access.
		+
		+
		+	==Schematic==
		+
		+	[[File:RS485GPIO Shield for RPI.jpg]]
		+

← Older revision		Revision as of 09:37, 20 February 2014
Line 46:		Line 46:

	Save the changes, and reboot. We will get an UART with baud rate of 115200.		Save the changes, and reboot. We will get an UART with baud rate of 115200.
		+
		+	==How to buy==
		+	Here to buy RS485/GPIO Shield for Raspberry Pi on [http://store.linksprite.com/rs485-gpio-shield-for-raspberry-pi/ store]