Raspberry Pi - pymodbus Youtube Series

I've been out of the game lately on my blog and wanted to give an update of my latest work on youtube.. I've been able to post a few video tutorials on pymodbus and wanted to show a preview of my youtube tutorial roadmap.

Pymodbus ModbusTCP - Reading Holding Registers
Pymodbus ModbusTCP - Reading & Writing Holding Registers
Pymodbus Raspberry Pi as Modbus Serial<->TCP Bridge
Pymodbus - RPi as ModbusTCP Slave Temperature Sensor
SCADA Datalogger - snap7 and Pymodbus
Pymodbus ModbusTCP - Reading And Writing Raspberry PI GPIO using ModbusTCP
Raspberry Pi - Tutorials - Snap7 Python - Raspberry Pi as S7 Device
Raspberry Pi - Tutorials - Snap7 Python - Reading & Writing Rpi GPIO using snap7 and Kepsever
Raspberry Pi - Tutorials - SCADA SQL Logger - snap7 and Pymodbus MSSQL

Dates are not yet decided.  I hope to get two of these a month. Let me know if you wish to see another one
So far these 4 are done:

Raspberry Pi - Tutorials - Pymodbus ModbusTCP - Setup & Quick Example (Writing To Twido M Memory)

 

Raspberry Pi - Python Snap7 - Mapping and Reading Datablocks

import snap7.client
from snap7.snap7types import *
from snap7.util import *


class DBObject(object):
    pass


offsets = { "Bool":2,"Int": 2,"Real":4,"DInt":6,"String":256}

db=\
"""
Temperature Real 0.0
Cold Bool 4.0
RPis_to_Buy Int 6.0
Db_test_String String 8.0
"""

def DBRead(plc,db_num,length,dbitems):
    data = plc.read_area(areas['DB'],db_num,0,length)
    obj = DBObject()
    for item in dbitems:
        value = None
        offset = int(item['bytebit'].split('.')[0])

        if item['datatype']=='Real':
            value = get_real(data,offset)

        if item['datatype']=='Bool':
            bit =int(item['bytebit'].split('.')[1])
            value = get_bool(data,offset,bit)

        if item['datatype']=='Int':
            value = get_int(data, offset)

        if item['datatype']=='String':
            value = get_string(data, offset)

        obj.__setattr__(item['name'], value)

    return obj

def get_db_size(array,bytekey,datatypekey):
    seq,length = [x[bytekey] for x in array],[x[datatypekey] for x in array]
    idx = seq.index(max(seq))
    lastByte = int(max(seq).split('.')[0])+(offsets[length[idx]])
    return lastByte


if __name__ == "__main__":
    plc = snap7.client.Client()
    plc.connect('10.10.55.109',0,0)
    itemlist = filter(lambda a: a!='',db.split('\n'))
    deliminator='\t'
    items = [
        {
            "name":x.split(deliminator)[0],
            "datatype":x.split(deliminator)[1],
            "bytebit":x.split(deliminator)[2]
         } for x in itemlist
    ]
    #get length of datablock
    length = get_db_size(items,'bytebit','datatype')
    meh = DBRead(plc,10,length,items)
    print """
    Cold:\t\t\t{}
    Tempeature:\t\t{}
    RPis_to_Buy:\t{}
    Db_test_String:\t{}
    """.format(meh.Cold,meh.Temperature,meh.RPis_to_Buy,meh.Db_test_String)
    plc.disconnect();

25+ Raspberry Compatible 1-Wire Host Boards/Hats

(sortable)

Image	Name / Link	Channels (Buses)	Extras	Price	Price per channel
	1-Wire Driver DS2482-800	8 ch.	---	£21.05	£2.63 / ch
	1-Wire Interface  Module	1 ch.	---	£5.93	£5.93 / ch
	R-Pi i2c 1-Wire OWFS Expansion Module	1 ch.	---	£17.99	£17.99 / ch
	I2C counter / 1-wire board	8 ch.	6x 16 bit Counter inputs	£69.99	£8.75 / ch
	Com Pi	1 ch.	RS232 Port	£12.99	£12.99 / ch
	1 Wire Pi Plus	1 ch.	---	£12	£12 / ch
	RP1 1-Wire GPIO Host Adapter	1 ch.	---	£7.95	£7.95 / ch
	RPI2 1-Wire Host Adapter	1 ch.	---	£14	£13.95 / ch
	RPI3 v1 1-Wire Host Adapter	8 ch.	RTC	£33	£4.12 / ch
	RPI3 v2 1-Wire Host Adapter	8 ch.	RTC	£33	£4.12 / ch
	AbioWire+	17 ch.	---	£42	£5.25 / ch
	1-Wire Mini Host	8 ch.	---	£15.26	£1.90 / ch
	1-Wire Automation System	8 ch.	expansion slot	£114	£14.25 / ch
	Raspberry Pi -9 Channel 1-Wire Board	9 ch.	RTC	£33	£3.66 / ch
	IoT-1Wire-1 module Board	8 ch.	---	£34	£4.25 / ch
	IoT-1Wire-1 module Board	1 ch. (5 ports)	---	£24	£24 / ch
	4 USB Hub & I2C AD/DA - 1-Wire   Board	1 ch.	RTC, 10bit ADC, 8bit DAC, 4 USB Hub	£52	£52 / ch
	7 USB Hub & I2C AD/DA - 1-Wire   Board	1 ch.	10bit ADC / 8bit DAC, 7 USB Hub	£58	£58 / ch
	Step Motor & I2C 1-Wire Board	1 ch.	8 ch output / step motor output	£21	£21 / ch
	One-Wire 17 Channels	17 ch.	---	£46.99	£2.76 / ch
	USB to One Wire converter	1 ch.	---	$24.60	$24.60 / ch
	S4: USB / 1-Wire Interface Card	1 ch.	---	€39	€39 / ch
	USB to 1-Wire RJ11	1 ch.	---	£26	£26 / ch
	I2C 1 Wire Click	8 ch.	---	£19.45	£2.43 / ch
	UART to 1 Wire Adapter (Retired)	1 ch.	---	---	---
	UniPi Expansion Board	1 ch.	Relays, Inputs, Outputs, Analog In/Out 0-10v	$134	$134 / ch
	PIGATOR Onewire	1 ch.	RTC, uplink header for expansion	£60	£60 / ch

Google Trends - Which Country Loves the Raspberry Pi the Most?

I often visit google.com/trends and decided to do a query on "Raspberry Pi" and here were the results:

Web Search

Image Search

Video Search

News Search

Google Shopping Search

10+ Things the Raspberry Pi Can Do As a Cheaper Replacement in Industrial Automation

The Raspberry Pi has many Industrial Control Applications and many ways to interface with current Industrial Protocols. 

I am starting a  Raspberry Pi Industrialized Google+ Community to gather people smarter than me to answer questions,give tutorials on Raspberry Pi and PLC interfaces, show present and upcoming raspberry pi hardware, and to show off their cool industrial projects using the Raspberry Pi. 

Since I'm a python fan here's a list of Ethernet/Serial Based Protocols I've found:

1. ModbusTCP/RTU using pymodbus 
2. *Profinet (a GitHub link) 
3. S7 Protocol using snap7 python (tutorial here)
• (Siemen's S7-300,S7-1500 / S7-200,S7-1200)
4. Koyo ECOM Protocol, (see my github, and here for example usage)
• DL05, DL06 PLCs
5. *EtherNet/IP (Link)

* I've not tested these libraries yet.

Here are the ways the Raspberry Pi can replace or enhance your Industrial Automation Process:

• Bridging Protocols.  Normally a protocol converter/bridge can cost $100+

• Modbus RTU <--> Modbus TCP,Siemens S7, Koyo ECOM, EtherNet/IP
• Modbus TCP <--> Siemens S7, Koyo ECOM, EtherNet/IP
• Any Other Serial ASCII Device <--> Modbus TCP, Siemens S7, Koyo ECOM, EtherNet/IP

• Cheap HMI Screen Replacement.  HMI can cost $1000s and since the Raspberry Pi can integrate with several protocols it could be a decent replacement to save some $$$, £££, or €€€ depending on where you live. Of course it may take some knowledge on either HTM5 with websockets or using QT as your front ends. 

• 7" Touch Screens for $50
• 15" Touch Screen Monitor for $172 
• 15" Open Frame Industrialized One for $335

• Serve Sensor Data.  Since many of the protocols developed in python, c++, and others include Server or RemoteIO like modes it can serve as a cheap sensor interface to a PLC.  Normally a temperature sensor/transmitter either 4-20mA or 0-10v costs $100+ also. (unless you get this PT100 RTD 4-20mA for $8).  What's great about the Pi is that is can handle tons of sensors and you can map it out it your programming.  Keep in mind that none of these solutions are hardened for the industrial environment (although neither is the Raspberry pi....)
• Replace a Temperature Sensor $2-$15 (Link for Different Sensors For Pi)
• Replace Humidity Sensors $5 with DHT22/AM2302 (These are Temperature/Humidity Sensors)
• Tank Level Monitoring can be replaced with Distance Sensors. (List of Distance Sensors Here)
• AC/DC Current Sensors. $7  (*Requires ADC Input Add-on Module) 
• Vibration Sensor $7 (*Requires ADC Input Add-on Module)
• 20+ More Analog Sensors Here

• Remote Relay I/O.

• Relay Boards.  I posted a while back some relay boards that sit on the Raspberry Pi as a Hat or Module. Here are other boards with Automation in mind
• PI-Cubes has released an awesome IO package mainly used for HVAC but has great IO abilities.
  (+Dalibor Zaric Nice!)
• UniPi
• 2 Analog 0-10v Inputs
• 1 Analog 0-10v Output
• 14 Digital Inputs
• 8 Relays
• 16 Channel Relay Boards 

• Remote Analog I/O

• 8 Ch 4-20mA Analog Input Board $50 for the Pi (also rs485, modbus)
• Ereshop 4 Ch analog input $29
  0-10v or 4-20mA

• Custom Raspberry Pi.  Lastly I am going to mention the customizable Raspberry Pi.  Yes, Customizable!  Element14 can customize the board to fit your process a little better.  Adding Wifi, more GPIO, onboard Flash memory, and others.

20+ Things to plug into your ADC input

A list of analog sensor for your projects by category.

Power Monitoring

1. AC/DC Current $4
2. AC Single Phase Voltage Sensor $6 

Outdoor Environmental

Weather

1. Wind Speed $70-$100
2. Temperature
3. Humidity
4. Wind Direction $70-$100
5. UV Light $5.99
6. Light $3.95
7. Lux Sensor $10

Garden

1. Liquid Level Sensor 1Meter @ $80
2. Soil Temperature $31
3. Capacitive Soil Moisture Probe $31
4. Water Pressure $20

Indoor Environmental

Air Quality

1. Gas Sensor - Hydrogen $8
2. Gas Sensor - Carbon Monoxide $12
3. Gas Sensor - Alcohol $7.50
4. Gas Sensor - CO2 $42
5. Gas Sensor - LGP $8
6. Flame Sensor $5

Presence 

1. Sound Sensor $4.46
2. Vibration Sensor $5.99
3. IR Distance Sensors $11.25

Converters

1. PWM to 0-5v