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--- traincontrol [2021/10/12 23:45]
dpisuperadmin [Next Steps]
+++ traincontrol [2021/10/15 02:45]
dpisuperadmin [Software]
@@ Line 43: / Line 43: @@
 A wireviz generated wiring diagram for the system is shown below.
 {{ wiki:trainwiring.png }}
+/*  Wiringviz source file for the above
+connectors:
+  Switch-Left:
+    type: Soldered wires
+    pinlabels: [Coil-Left, Common, Coil-Straight]
+    show_name: false
+    notes: Track Switch Left
+  Switch-Right:
+    type: Soldered wires
+    pinlabels: [Coil-Right, Common, Coil-Straight]
+    show_name: false
+    notes: Track Switch Right
+  DC-IN:
+    type: Barrel
+    subtype: female
+    pinlabels: [V+, GND]
+    show_name: false
+    notes: Power Adapter
+  SMR-5:
+    type: screw terminal
+    pinlabels: [V+, GND, V5.0, GND]
+    show_name: false
+    notes: SMR-5 regulator
+  DRV4:
+    type: screw terminal
+    pinlabels: [V+, GND, O1, O2, O3, O4]
+    show_name: false
+    notes: DRV4 Open-Drain Driver
+  D7HB:
+    type: screw terminal
+    pinlabels: [V+, GND, A1, A2, B1, B2]
+    show_name: false
+    notes: D7HB H-bridge
+  SBC:
+    type: Soldered wires
+    pinlabels: [V5.0, GND]
+    show_name: false
+    notes: Single Board Computer
+  Track:
+    type: screw terminal
+    pinlabels: [Rail-1, Rail-2]
+    show_name: false
+    notes: Track
+cables:
+  W1:
+    colors: [RD,BK]
+  W2:
+    colors: [RD,BK]
+  W3:
+    colors: [RD,WH]
+  W4:
+    colors: [RD,WH]
+  W5:
+    colors: [GN,YE,RD]
+  W6:
+    colors: [GN,YE,RD]
+  W7:
+    colors: [RD,WH]
+connections:
+  -
+    - DRV4:  [4,1,3]
+    - W5:    [1,2,3]
+    - Switch-Left: [1,2,3]
+  -
+    - DRV4:  [5,1,6]
+    - W6:    [1,2,3]
+    - Switch-Right: [1,2,3]
+  -
+    - DRV4:  [1,2]
+    - W7:    [1,2]
+    - D7HB:  [5,2]
+  -
+    - DC-IN: [1-2]
+    - W1:    [1-2]
+    - SMR-5: [1-2]
+  -
+    - D7HB:  [1-2]
+    - W2:    [1-2]
+    - SMR-5: [1-2]
+  -
+    - SMR-5: [3,4]
+    - W3:    [1-2]
+    - SBC:   [1-2]
+  -
+    - D7HB:  [3,4]
+    - W4:    [1,2]
+    - Track: [1,2]
+*/
 ==== Peripherals ====
-The four daughter cards in the system are the D7HB dual H-bridge, the DRV4 quad open-drain driver, the SW4 quad slide switch, and the SLIDE4 quad slide pot.  The Linux (and FPGA) drivers for these are the DC2 dual DC motor controller, the OUT4 quad binary output, the IN4 quad binary input, and the SLIDE4 quad slide pot input.
+The four  //cards// in the system are the D7HB dual H-bridge, the DRV4 quad open-drain driver, the SW4 quad slide switch, and the SLIDE4 quad slide pot.  The Linux (and FPGA) //peripherals// for these are the DC2 dual DC motor controller, the OUT4 quad binary output, the IN4 quad binary input, and the SLIDE4 quad slide pot input.
 We used the Demand Peripherals support page "Build your FPGA Image"
@@ Line 74: / Line 164: @@
 <tab10> dpset out4 outval f \\
 Test one switch with the commands: \\
-<tab10> dpset out4 outval e ; sleep 0.1 ;dpset out4 outval f \\
+<tab10> dpset out4 outval e ; sleep 0.05 ;dpset out4 outval f \\
 Once the program starts we can read the state of the switches and the position of the slide pots using dpget commands.
@@ Line 105: / Line 195: @@
 At program start time we want to force the speed of the engine to be zero until the slide pot is actually set to zero, at which time the pot can start to control the engine speed.
+<code>
+#!/usr/bin/env python
+import socket
+import sys
+import time
+# The purpose of this program is to control the speed
+# and direction of model railroad.  The underlying
+# hardware is a Demand Peripherals Baseboard4 FPGA card
+# along with a quad slide switch card, a quad slide pot,
+# and dual H-bridge.
+#   FPGA based peripherals control this hardware through
+# a daemon supplied by Demand Peripherals.  The Linux
+# visible peripherals are a in4 peripheral in slot 2,
+# a slide4 peripheral in slot 3, and a dc2 peripheral
+# in slot 4.  Please see their respective pages at :
+# http://demandperipherals.com/peripherals.html
+#
+# This program opens one socket to dpserver for commands
+# to the FPGA card.  Normally there is one socket per
+# sensor and one for commands.  In this simple program
+# we use polling to read the slide pot and direction
+# switch.
+#
+# Switch 0x1 sets the direction. Slide pot 1 sets the
+# speed.  As a safety measure, the direction can not
+# be set unless the speed is set to zero.
+def send_cmd(socket , str ) :
+    "Send Command to FPGA deamon"
+    socket.send(str)
+    response = ''
+    while True :
+        c = sock_cmd.recv(1).decode()  # for the four \\ character responses
+        if c =='\\' :
+            break
+        response += c
+    if ((len(response) > 0) and (response[0] == 'E')) :
+        # Error if first character of response is an E
+        print("Command : ", str)
+        print("Response : ", response)
+    #print("Command : ", str)
+    #print("Response : ", response)
+    return response
+try:
+    sock_cmd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    sock_cmd.connect(('localhost', 8870))
+    # Init H-bridge PWM frequency to 50 Hz and mode to brake.
+    # Set the H-bridge watchdog timer to 300 ms.
+    response = send_cmd(sock_cmd, b'dpset dc2 mode0 b \n') # brake is only at init time
+    response = send_cmd(sock_cmd, b'dpset dc2 power0 0 \n')
+    response = send_cmd(sock_cmd, b'dpset dc2 pwm_frequency 50 \n')
+    response = send_cmd(sock_cmd, b'dpset dc2 watchdog 400 \n')
+    # init track swith states to unknown
+    switch_left = "u"
+    switch_right = "u"
+    # loop forever getting speed and direction
+    while True:
+        # Get speed and switch settings
+        positions = send_cmd(sock_cmd, b'dpget slide4 positions\n')
+        position1 = int(positions[:4])
+        speed = int(100 * (1024 - position1) / 1024)
+        switches = send_cmd(sock_cmd, b'dpget in4 inputs\n')
+        # Set track switches if controlling slide switches changed
+        if (int(switches[0],16) & 8 == 8) and (switch_left != "l") :
+            switch_left = "l"
+            response = send_cmd(sock_cmd, b'dpset out4 outval d \n')
+            time.sleep(0.05)
+            response = send_cmd(sock_cmd, b'dpset out4 outval f \n')
+        elif (int(switches[0],16) & 8 == 0) and (switch_left != "s") :
+            switch_left = "s"
+            response = send_cmd(sock_cmd, b'dpset out4 outval e \n')
+            time.sleep(0.05)
+            response = send_cmd(sock_cmd, b'dpset out4 outval f \n')
+        if (int(switches[0],16) & 4 == 4) and (switch_right != "r") :
+            switch_right = "r"
+            response = send_cmd(sock_cmd, b'dpset out4 outval b \n')
+            time.sleep(0.05)
+            response = send_cmd(sock_cmd, b'dpset out4 outval f \n')
+        elif (int(switches[0],16) & 4 == 0) and (switch_right != "s") :
+            switch_right = "s"
+            response = send_cmd(sock_cmd, b'dpset out4 outval 7 \n')
+            time.sleep(0.05)
+            response = send_cmd(sock_cmd, b'dpset out4 outval f \n')
+        #print("switches : ", switch_left, switch_right)
+        # Set engine direction if speed is zero
+        if speed == 0:
+            if int(switches[0],16) & 1 == 1 :
+                response = send_cmd(sock_cmd, b'dpset dc2 mode0 f \n')
+            else :
+                response = send_cmd(sock_cmd, b'dpset dc2 mode0 r \n')
+        # Always set engine speed to keep watchdog alive
+        response = send_cmd(sock_cmd, b'dpset dc2 power0 ' b"%d" b'\n' % speed)
+        time.sleep(0.05)
+        #print("speed : ", speed)
+except KeyboardInterrupt:
+    # exit on Ctrl^C
+    sock_cmd.close()
+    sys.exit()
+except socket.error:
+    print("Couldn't connect to dpdaemon")
+    sys.exit()
+</code>

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