Raspi and EV3-G - Revision history

Mol: /* Projects */

2020-11-10T15:28:17Z

Projects

← Older revision		Revision as of 18:28, 10 November 2020
Line 3:		Line 3:
	[[Raspberry Pi Bluetooth controlled steerable robot]]		[[Raspberry Pi Bluetooth controlled steerable robot]]

			CV2:
			* Pacman
			* Maze
			* Swarm robots
			*

			Gyro controlled

	== Pairing ev3 and Raspi ==		== Pairing ev3 and Raspi ==

Mol: /* Pairing ev3 and Raspi */

2020-11-05T18:59:04Z

Pairing ev3 and Raspi

← Older revision		Revision as of 21:59, 5 November 2020
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	[[https://raspberrypi.stackexchange.com/questions/78155/using-dev-rfcomm0-in-raspberry-pi\| To establish Bluetooth]] connection, need to create the serial device that binds to the paired Ev3 robot:		[[https://raspberrypi.stackexchange.com/questions/78155/using-dev-rfcomm0-in-raspberry-pi\| To establish Bluetooth]] connection, need to create the serial device that binds to the paired Ev3 robot:
	<syntaxhighlight>		<syntaxhighlight>
	sudo rfcomm ~~connect~~ rfcomm0 00:16:53:53:64:E1		sudo rfcomm bind rfcomm0 00:16:53:53:64:E1
	</syntaxhighlight>		</syntaxhighlight>
	or use		or use
Line 67:		Line 67:
	</syntaxhighlight>		</syntaxhighlight>
	where the last number is the communication channel. It needs to be unique.		where the last number is the communication channel. It needs to be unique.


	== Transmitting From EV3-G To Raspberry Pi ==		== Transmitting From EV3-G To Raspberry Pi ==

Mol at 20:23, 2 November 2020

2020-11-02T20:23:57Z

← Older revision		Revision as of 23:23, 2 November 2020
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			== Projects ==

			[[Raspberry Pi Bluetooth controlled steerable robot]]


	== Pairing ev3 and Raspi ==		== Pairing ev3 and Raspi ==

Mol at 20:21, 2 November 2020

2020-11-02T20:21:53Z

← Older revision		Revision as of 23:21, 2 November 2020
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	~~== Error Messages so far ==~~

	~~raspberry pi device added succesfuly but failed to connect~~

	~~Connection failed: _blueman.RFCOMMError: Failed to get rfcomm channel~~

	~~Paired successfully but this device has no services which can be used with raspberry pi~~


	== Pairing ev3 and Raspi ==		== Pairing ev3 and Raspi ==

Line 131:		Line 122:

	The brick says once ''Hello' and after that wants to connect to raspi. If the wrong password is given, the Python code will shutdown. The <code>update</code> in the EV3-G's Bluetooth command do not work.		The brick says once ''Hello' and after that wants to connect to raspi. If the wrong password is given, the Python code will shutdown. The <code>update</code> in the EV3-G's Bluetooth command do not work.


			== Error Messages so far ==

			raspberry pi device added succesfuly but failed to connect

			Connection failed: _blueman.RFCOMMError: Failed to get rfcomm channel

			Paired successfully but this device has no services which can be used with raspberry pi

Mol at 20:21, 2 November 2020

2020-11-02T20:21:23Z

@@ Line 1: / Line 1: @@
 == Error Messages so far ==
 raspberry pi device added succesfuly but failed to connect
@@ Line 12: / Line 8: @@
-=== Pairing ev3 and Raspi ===
+== Pairing ev3 and Raspi ==
 Pairing and connecting is easy using X11.
@@ Line 76: / Line 72: @@
 where the last number is the communication channel. It needs to be unique.
-*http://www.geekdroppings.com/2018/01/21/raspberry-pi-and-the-lego-ev3-connected-by-bluetooth/
+== Transmitting From EV3-G To Raspberry Pi ==
 [[File:EV3BT_sendTo.png|thumb|Two simple scripts to send data to Raspberry Pi.]]
@@ Line 126: / Line 105: @@
 </syntaxhighlight>
-=== Transmitting From Raspberry Pi To EV3-G ===
+== Transmitting From Raspberry Pi To EV3-G ==
 First start the Python script on the Raspberry Pi and then run the EV3 code.
@@ Line 152: / Line 131: @@
 The brick says once ''Hello' and after that wants to connect to raspi. If the wrong password is given, the Python code will shutdown. The <code>update</code> in the EV3-G's Bluetooth command do not work.

Mol: Created page with " == Raspi and Ev3-G == === Error Messages so far === raspberry pi device added succesfuly but failed to connect Connection failed: _blueman.RFCOMMError: Failed to get rfc..."

2020-11-02T20:18:35Z

Created page with " == Raspi and Ev3-G == === Error Messages so far === raspberry pi device added succesfuly but failed to connect Connection failed: _blueman.RFCOMMError: Failed to get rfc..."

New page

== Raspi and Ev3-G ==

=== Error Messages so far ===

raspberry pi device added succesfuly but failed to connect

Connection failed: _blueman.RFCOMMError: Failed to get rfcomm channel

Paired successfully but this device has no services which can be used with raspberry pi

=== Pairing ev3 and Raspi ===

Pairing and connecting is easy using X11.

<code>bluetooth-agent</code> command do not exist on Jessie. Use <code>bluetoothctl</code> with the following script shown on [https://raspberrypi.stackexchange.com/questions/50496/automatically-accept-bluetooth-pairings Stackechange]:

<syntaxhighlight>
sudo bluetoothctl <<EOF
power on
discoverable on
pairable on
agent NoInputNoOutput
default-agent
EOF
</syntaxhighlight>

<syntaxhighlight>
bluetoothctl
power on
discoverable on
scan on
</syntaxhighlight>

<syntaxhighlight>
trust <ev3 address>
pair <ev3 address>
agent on OR default-agent
devices
quit
</syntaxhighlight>

<syntaxhighlight>
Device 24:71:89:BA:DA:61 ev3dev
Device 00:16:53:53:64:E1 EV3
</syntaxhighlight>

It helps to restart Ev3.

The file <code>/etc/bluetooth/rfcomm.conf</code>
<syntaxhighlight>
rfcomm0 {
# Automatically bind the device at startup
bind no;
# Bluetooth address of the device
device 00:16:53:53:64:E1 ;
# RFCOMM channel for the connection
channel 2;
# Description of the connection
comment "This is Device EV3's serial port.";
}
</syntaxhighlight>

[[https://raspberrypi.stackexchange.com/questions/78155/using-dev-rfcomm0-in-raspberry-pi| To establish Bluetooth]] connection, need to create the serial device that binds to the paired Ev3 robot:
<syntaxhighlight>
sudo rfcomm connect rfcomm0 00:16:53:53:64:E1
</syntaxhighlight>
or use
<syntaxhighlight>
sudo rfcomm bind /dev/rfcomm0 00:16:53:53:64:E1 1
</syntaxhighlight>
where the last number is the communication channel. It needs to be unique.

=== Some links ===

*http://www.geekdroppings.com/2018/01/21/raspberry-pi-and-the-lego-ev3-connected-by-bluetooth/
*https://www.hackster.io/KKE/raspberry-pi-lego-mindstorms-ev3-bluetooth-communication-aa42e2
*https://siouxnetontrack.wordpress.com/2013/09/27/connecting-the-pc-to-our-ev3/
*https://gipprojects.wordpress.com/2013/11/29/using-python-and-raspberry-pi-to-communicate-with-lego-mindstorms-ev3/
*https://ev3lessons.com/en/ProgrammingLessons/beyond/EV3PiLight.pdf
*https://ev3lessons.com/en/ProgrammingLessons/beyond/EV3PiCommunicator.pdf
*http://www.abrowndesign.com/2018/10/25/sending-bluetooth-messages-from-raspberry-pi-to-lego-ev3-stock-firmware/
*https://github.com/lehoff/ev3bt/

<gallery>
MaksymShyte.png|Maksym Shyte @ http://www.geekdroppings.com/2018/01/21/raspberry-pi-and-the-lego-ev3-connected-by-bluetooth/
KoenKempeneers.png|Koen Kempeneers @ https://www.hackster.io/KKE/raspberry-pi-lego-mindstorms-ev3-bluetooth-communication-aa42e2
HansOdenthal.png|Hans Odenthal @ https://siouxnetontrack.wordpress.com/2013/09/27/connecting-the-pc-to-our-ev3/
</gallery>

=== Transmitting From EV3-G To Raspberry Pi ===

[[File:EV3BT_sendTo.png|thumb|Two simple scripts to send data to Raspberry Pi.]]

<syntaxhighlight lang="python">
#hackster.io -> Raspberry Pi Lego Mindstorms ev3 bluetooth
import serial
import time
EV3 = serial.Serial('/dev/rfcomm0')
print("Listening to")
try:
while True:
n = EV3.inWaiting()
if n != 0:
s = EV3.read(n)
print( s )
for n in s:
print( "x%02X" % (n), end=' ' )
#print( chr( int(n) ) )
print()
time.sleep(0.5)
except KeyboardInterrupt:
pass
EV3.close()
</syntaxhighlight>

The received data looks like
<syntaxhighlight>
b'\x12\x00\x01\x00\x81\x9e\x07Status\x00\x04\x00Hei\x00'
x12 x00 x01 x00 x81 x9E x07 x53 x74 x61 x74 x75 x73 x00 x04 x00 x48 x65 x69 x00
</syntaxhighlight>

=== Transmitting From Raspberry Pi To EV3-G ===

First start the Python script on the Raspberry Pi and then run the EV3 code.

[[File:BT ev3g hello.png|thumb|Multiple hellos.]]

<syntaxhighlight lang="python">
#! /usr/bin/env/ python3
import serial
import time
import EV3BT

EV3 = serial.Serial('/dev/rfcomm0')
s = EV3BT.encodeMessage(EV3BT.MessageType.Text, 'abc', 'Have fun')
for i in range(10):
print(i)
s = EV3BT.encodeMessage(EV3BT.MessageType.Text, 'abc', 'Have fun'+ str(i))
#s = EV3BT.encodeMessage(EV3BT.MessageType.Numeric, 'abc', 123)
#s = EV3BT.encodeMessage(EV3BT.MessageType.Text, 'abc', 'Have fun')
print( EV3BT.printMessage(s) )
EV3.write(s)
time.sleep(1)
EV3.close()
</syntaxhighlight>

The brick says once ''Hello' and after that wants to connect to raspi. If the wrong password is given, the Python code will shutdown. The <code>update</code> in the EV3-G's Bluetooth command do not work.