This is an old revision of the document!

WIOpi

WIO Overview | WIO Setup | WIO Control | User Bitmaps | WIO Firmware | WIO CAM | WIO Mobile | Cable | LEDScript | WIOpi

Work In Progress

Before mounting the header on the Zero, check this WIOpi-01

Introduction

WIOpi is a program targeted for the Raspberry Pi and its GPIO. (Model 1, 2, 3, 4 and Zero.)
The hardware requirements and support are the same as for RocNetNode.
By running the WIOpi program on the Raspberry Pi, it will behave and process like a WIO on ESP base.

WIOpi runs in context of user pi.

The user pi is default in the groups gpio, i2c and spi, so no need to run WIOpi in super user context.
Note: Type mobile should run in root context to be able to run a high performance motor thread.

$ groups
pi adm dialout cdrom sudo audio video plugdev games users input netdev gpio i2c spi

The following files and directories are extracted:

.
├── cam
│   └── cam.py
├── reboot.sh
├── scripts
│   └── Disco00.led
├── startwiopi.sh
├── update.sh
└── wiopi

The commands to start and stop the cam.py Python script can be specified in the wiopi.ini.
Defauls are:

    <var name="startcam" vt="string" defval="nohup python3 cam/cam.py &amp;"/>
    <var name="stopcam" vt="string" defval="killall python3"/>

Install

Activate I2C, SPI and UART in the raspi-conf utility.

cd
mkdir WIOpi
cd WIOpi
wget https://wiki.rocrail.net/rocrail-snapshot/WIOpi-ARMHF.tar.gz
tar xf WIOpi-ARMHF.tar.gz
rm WIOpi-ARMHF.tar.gz

Add a crontab task:

@reboot /home/pi/WIOpi/startwiopi.sh

The ARMHF build runs also under PiOS 64bit. (ARM64)

Command Line Options

Option	Description
-t <filename>	trace filename
-server <ip>	Rocrail server IP or DNS name
-id <1…255>	WIOpi Node ID
-softpwm	Use software PWM for servos to enable play sound.

Pinout

The Pinout and mapping is printed in the console after startup.
It depends on the configuration found in the wiopi.ini.
See for Raspberry Pi Pinout information: https://de.pinout.xyz

Supported Hardware

Pi01
Pi01CAN
Pi02 (max. 4 = 128 I/O)
Pi03 (max. 4 = 64 Servo)
Pi06 (Power & Patch)
Pi08 (max. 8 = 128 LED. Output address < = 128)
ID12 RFID reader on Pi01
SSD1306 / SH1106 OLED (max. 2, restricted by the I2C addressing of the SSD1306 / SH1106)
Note: The SH1106 seems incompatible with the Pi01, I2C Driver, so it must be connected directly to the I2C pins.
HT16K33 (max. 2 Clock)
4 or 3 wire stepper motor
BMx280 (max. 2 Environment)
GCA214 RailCom reader on Pi01 (PiOS 32bit only because of the none standard baudrate of 250000.)
Play sound with "omxplayer" (Without prefix forward slash)
Mobile soft PWM for controlling a DC Motor, MOSFET or H-Bridge. ¹⁾
WS2801 RGB LEDs over SPI (Output address > 128)
- LEDScript support in case Port Type is set to Macro.
2 Servos on the hardware PWM pins (phys. 32 & 33). ²⁾
Analog inputs: PCF8591

Sound

The Servo outputs, PWM0 and PWM1, can also be used for audio:

dtoverlay=pwm-2chan,pin=12,func=2,pin2=13,func2=4

The filter is quit simple: (Example is for just one channel, and not tested.)

                  1µ
                 || | 
Servo0 -+---+----|| |----+
        |   |    || |    |   /|
       +-+  |            |  / |
       |1| ---         +---+  |
       |5| --- 33n     |   |  |
       |0|  |          |   |  |
       +-+  |          +---+  |
        |   |            |  \ |
   GND -+---+------------+   \|

Pi01

LED functions

Both LEDs will flash fast on a show command to identify itself.
Another show command will stop this flashing.

LED1 (green)	Description
Off	WIOpi does not run, or no GPIO access granted.
Slow flash	Normal function.
Fast flash	No Rocrail server connection.

LED2 (red)	Description
Off	Idle communication.
Flash	Packet received.

Pushbutton

In case both LEDs are flashing to identify itself, it will stop this mode.
Otherwise it sends a query response to the Server.

Signals on Pi02/Pi08/WS2801

Signals Support is also available on the Pi02, in case no Pi08 is connected.

Pi08: 1…128
Pi02: 1…128
WS2801: 129…256 (mapped on 1…128)

Stepper Control

See for turntable setup: WIO Stepper

Function	Header	GPIO
4 Wire
IN1 (Coil 1)	27	0
GND	9	-
IN2 (Coil 2)	29	5
IN3 (Coil 3)	31	6
IN4 (Coil 4)	35	19
HALL (Calibrate)	37	26

Function	Header	GPIO	Example TB6600
3 Wire
STEP(Clock)	27	0	CLK+
GND	9	-	EN-, DIR-, CLK-
DIR	29	5	DIR+
ENABLE	31	6	EN+
HALL (Calibrate)	37	26

WS2801

WS2801	Header	I/O1	Function
DI	19 MOSI	6	Digital In
CI	23 SCLK	8	Clock In
GND	25 GND	2	Ground

Output settings for LEDScript

Address > 128 or count, ON Parameter, is set to zero.
Options Color, Type Macro.

WIOpi-01

Files

https://gitlab.com/rocrail/wio/-/tree/master/hardware/WIOpi

The Rpi-Zero header mounted on the bottom side. (without factory header)
The Rpi-1/4 header mounted on the top side. (factory default)
Short header on the Rpi-1; No native servo support.

 --------------------  
| Rpi0 bottom hdr    |
 --------------------
 |  |
  --       Zero set top
 |  |
 |  |
 ----------------------------------------
| WIOpi-01                               |
 ----------------------------------------
 |  |                                 || 
 |  |                                 ||
  --       Pi2++ piggy bag            ||
 |  |                                 ||
 ----------------------------------------
| Rpi1/4 top hdr                         |
 ----------------------------------------

CAM

The CAM can be used parallel with WIOpi as documented here:

Raspberry Pi Zero & CAM

top - 11:54:34 up 26 min,  2 users,  load average: 1.53, 1.27, 0.85
Tasks:  77 total,   1 running,  76 sleeping,   0 stopped,   0 zombie
%Cpu(s):  7.2 us, 15.4 sy,  0.0 ni, 71.9 id,  0.0 wa,  0.0 hi,  5.5 si,  0.0 st
MiB Mem :    368.4 total,    222.4 free,     73.5 used,     72.5 buff/cache
MiB Swap:      0.0 total,      0.0 free,      0.0 used.    244.2 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                                              
  527 root      20   0       0      0      0 I   8.1   0.0   0:00.48 kworker/u2:2-brcmf_wq/mmc1:0001:1                                                    
  435 pi        20   0  120260  20208   8232 S   7.8   5.4   1:56.07 python3                                                                              
  301 pi        20   0    9944   2528   2072 S   7.5   0.7   2:00.87 wiopi                                                                                
  526 root      20   0       0      0      0 I   2.9   0.0   0:00.61 kworker/0:1-events                                                                   
  521 pi        20   0   10280   2972   2516 R   1.3   0.8   0:01.73 top

Link to stream:

http://<zero-name>:8081

Mobile

Function 8 can be used to activate and deactivate the CAM.

I2C Slaves

WIOpi supports up to 4 I2C Slaves.
The reserved I2C device addresses are 0x7C, 0x7D, 0x7E and 0x7F.

To address a pin on a slave, the following parameters are involved:

Node ID: The ID of the WIOpi
Address: Pin number
Port: Slave I2C ID

Supported Rocrail objects:

Digital output

Monitor trace DOUT(0x0A) on Pin 5(data[0]) off(data[1]):

opc=0x0A dlc=5 data=05 00 00 00 7C 00 00 00

Ten times a second, the slaves are polled for their input pin state. (If any defined.)

20210105.083513.532 w9999I main     OWire    0187 I2C device found at 0x7C
20210105.083513.542 w9999I main     ODisplay 0392 init SSD1306 device 0x3C geometry=3
...
20210105.083513.886 w9999I doManage OManager 0101 read reg array slave 0x7C rc=2: opc=0x99 11 66

Note 1: The Arduino Nano cannot handle error free I2C speeds above the default 100kHz.

User Pin Definitions

To remap pins for Pi01, Stepper and Mobile, the following child nodes in the wiopi.ini can be used:

<wiopi server="localhost">
  <pindef fn="PWM" nr="12"/>
  <pindef fn="IN1" nr="7"/>
</wiopoi>

The nr attribute resembles the connector number, not the GPIO.

Name(fn)	Description	Remark
LED1	Pi01 LED1 output
LED2	Pi01 LED2 output
Button	Pi01 Button input
IN1	Stepper IN1 output	3W Clock
IN2	Stepper IN2 output	3W Dir
IN3	Stepper IN3 output	3W Enable
IN4	Stepper IN4 output
CAL	Stepper calibration input
PWM	Mobile PWM output
FWD	Mobile forwards relay pulse output
REV	Mobile reverse relay pulse output
LIGHTS1	Mobile lights Cab 1 output
LIGHTS2	Mobile lights Cab 2 output

Auto Server Connect

WIOpi use the R2RNet service to detect the Rocrail server in the LAN.
This service must be activated in the server settings.

If Auto Server Connect doesn't work (f.e. if the router doesn't support UDP Multicast) you can at the Server IP to the winopi.ini:

<wiopi server="hier die IP den RR Servers" serialdev="/dev/ttyAMA0" nid="90" nodename="WIOpi">

Mobile Dual Motor

Locomotives with dual motors require dual H-Bridge support.
Set the "dualmotor" option to "true" in the wiopi.ini to enable this.
The second H-Bridge connects to the I/O2 connector on pin 4, 5 and 6.
The WIO-Drive, without ESP, can be used as second H-Bridge. Mount only those parts needed for controlling the H-Bridge. Do not place the rectifier, but wire it.

I/O2	H-Bridge	Rpi Conn	WIODrive
2	GND	25	IBB1-3
4	IN2	29	IBB1-2
5	IN1	31	IBB1-1
6	ENA	35	ESC1-3

¹⁾

WIOpi must be started with sudo to generate a good quality PWM.

²⁾

WIOpi must be started with sudo to be able to use the PWM outputs.

Innovative Model Railroad Control System

Table of Contents