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--- getting_started:tutorials:oneaxis_bbb [2019/10/14 17:02] – graf
+++ getting_started:tutorials:oneaxis_bbb [2021/02/12 17:22] (current) – [Experimental Setup with a Beaglebone Blue Board] ursgraf
@@ Line 1: / Line 1: @@
 ====== Experimental Setup with a Beaglebone Blue Board ======
-Use a [[https://wiki.ntb.ch/infoportal/embedded_systems/ti_sitara_am335x/beaglebone_blue/start|Beaglebone Blue]]. Connect all the necessary signals according to your hardware configuration file.
+Use a [[https://wiki.ntb.ch/infoportal/embedded_systems/ti_sitara_am335x/beaglebone_blue/start|Beaglebone blue]] board. Connect all the necessary signals according to your hardware configuration file.
 ===== Analog Output =====
-There are 4 connectors denoted with DC Motors. Connect number 1 with the motor. Before testing plug in the 12V DC power supply or the Li-Po battery, otherwise the motors won't run. ssh into the Beaglebone blue board and run
+There are 4 connectors denoted with //DC Motors//. Connect number 1 with the motor. Before testing plug in the 12V DC power supply or the Li-Po battery, otherwise the motors won't run. ssh into the Beaglebone blue board and run
 <code>
-debian@beaglebone:$ rc_test_motors -m 1 -d 1
+ost@bblue:$ rc_test_motors -m 1 -d 1
 </code>
 //-m 1// selects the first motor while //-d 1// specifies a duty cycle of 1. The motor should run in positive direction. If the motor turns in the opposite direction, change the + and - wire of the motor. You can stop the program by pressing ''Ctrl-C''. The test program is located in ///usr/bin// and can be run from anywhere.
+===== Enable Signal =====
+On the Beaglebone blue we do not use a motor controller and therefore, we do not use this signal. However, we put the signal onto the green led on the board.
-  * Analog output and enable signal to the motor controller
+===== Encoder Inputs =====
-  * Encoder outputs (A/B signals) to the decoder inputs
+There are 4 connectors denoted with //4 Quadrature encoder inputs//. Connect number 1 with your encoder. Make sure that your encoder works with 3.3V as delivered by this connector. Test the encoder with
-  * motor controller ready signal to a digital input
+<code>
-  * emergency button to a digital input
+ost@bblue:$ rc_test_encoders
+</code>
+Turning the motor in positive direction must lead to the encoder counting upwards. If not, change the A and B signals.
-IMPORTANT Make sure that a positive voltage on the motor leads to the encoder counting upwards. If the opposite is the case, either change the cables or change the hardware configuration file. \\
+===== Ready Signal =====
-IMPORTANT On the beaglebone blue board, you don't need a motor controller. Hence, you do not need the enable signal. Tie the ready signal to logic one.
+The ready signal signals to the controller that the motor controller has powered up. As there is no external motor controller on the Beaglebone blue we simply put this signal on a digital input pin which is connected to the on board push button //Mode//.
+===== Emergency Signal =====
+The emergency signal is used to bring the application in a safe mode. We put this input signal on a digital input pin which is connected to the on board push button //Pause//. Later when the application runs we can cause the safety system to switch to an emergency state by pressing the //Pause// button.