Mission

        This website supports the development and maintenance of my 
        projects; I am Ron[ald] Sutherland (of Tempe Arizona, USA). 
        My interest are transducers, sensors, bare metal micro-controllers, 
        differential communication (RS-422/485), power conversion, 
        measurement, and gardening. 

Purpose

        This is how I learn embedded development (both hardware 
        and software), it provides a place to demonstrate and prototype 
        ideas for data acquisition and controls (for gardens).
        
        

Support/Warranty

        THE COPYRIGHT HOLDERS PROVIDE THE DESIGN MATERIALS "AS IS" WITHOUT WARRANTY 
        OF ANY KIND. THE ENTIRE RISK AND COST AS TO THE QUALITY, FUNCTION, DEFECTS AND 
        PERFORMANCE IS WITH YOU. e.g. these design materials may be totally 
        unsuitable for any purposes.

        These design material/board/kit is intended for use for ENGINEERING DEVELOPMENT, 
        DEMONSTRATION, OR EVALUATION PURPOSES ONLY and is not considered to 
        be finished end-product(s) fit for general consumer use. Persons handling the 
        product(s) must have electronics training and observe good electronic engineering 
        practice standards. This is due to the components and assemblies referenced 
        lacking: protective and environmental (UL/CSA or CE), electromagnetic 
        compatibility (FCC), and restricted substances (RoHS) consideration and thus 
        may not meet the markets approval requirements.
        
        

Methods

        Design Indexes

        Categories have descriptions that mention what type of 
        documentation is within. This is managed with Mercurial 
        [*] using this setup [**]. Issue tracking [***]

        *       http://en.wikipedia.org/wiki/Mercurial
        **      http://epccs.org/indexes/Document/DvlpNotes/
        ***     https://github.com/epccs/ please use the repository issue system

        Forum on rpubus.org

        This is open source hardware, so a bulletin board using phpBB
        is an approporate way to allow those interesed to help. 
        Note: the domain is at rpubus.org, since I have apparently got
        stuff messed up on epccs.org with all the tinkering I did years 
        back (e.g. the MOJO install scrips crash).

         TO DO LIST:

        Market Place: Opencart[*] or Tindie [**] (not sure yet).

        *      http://www.opencart.com/
        **     https://www.tindie.com/

        Contacts

        "epccs.[org|com]" is not a company it is a domain name, it has been in use
        for some time as indicated.
                Ronald Sutherland (owner) 
                        
                        Electrical Engineer experienced with power, sensors, firmware, 
                        circuit board, hardware, and test. 
                        cover letter
                        resume
                        
                        View Ron Sutherland's profile on LinkedIn
                        
                        GitHub
                        
        

News

        Can a Pi Zero be mounted on a shield with the RPU_BUS and act as the host? It is 
        in the works so I will soon find out RPUpi.
        The RPU_BUS is multidrop RS422 with RX/TX pair and an out of band 
        RS485 pair used for management. I have had good luck running avrdude 
        and the bootloaders xboot and optiboot over the bus. The boot loaders 
        are not multi-drop so the bus management needs to put the bus in a 
        point to point mode before boot loading.
        
        The Arduino Uno is robust in how it is used (not in the sense of use
        for life support). No matter how messed up the firmware I loaded is I 
        can upload a new version, this is actually quite an amazing feature, 
        given that the firmware is, in fact, the binary executable. Usually, 
        users have to write applications as a script that that is interpreted 
        through a protective system. Sometimes it is a literal script 
        (e.g. ladder logic, Basic, Lua), other times as a p-code machine 
        (Java, Python, Mono/.NET). Unfortunately for most programmable 
        devices, machine code from C/C++ (or Assembly) would be too easy to 
        get wrong and result in self-destruction of the hardware. Allowing the 
        user to program with machine code also allows the user to misconfigure 
        the hardware. So why does an Uno and the Arduino.cc IDE have so 
        few problems. An AVR ATmega328p (e.g. Uno MCU) can be 
        programmed with an ISP tool, but device configuration is tricky and 
        bricking can occur (microcontroller configuration flags are not 
        forgiving). But the Arduino IDE uploads to a bootloader which can not 
        change the flags, so that protects the user from setting the flags 
        wrong. Historically programmable devices (e.g. PLC) use a multidrop 
        bus (RS-485) which requires that both the software tool that loads the 
        firmware and the bootloader that receives the firmware would need to 
        know how to operate the half-duplex transceiver. Furthermore, once the 
        upload machine code runs it can set the transceiver into a state that 
        could both damage it and/or prevent further firmware uploads. The Uno 
        solves this by using a simple but unstoppable, point to point RS-232 
        (TTL level) connection. In truth, Arduino's strong firmware upload 
        method is not done by the IDE, it is avrdude and the bootloader.
        

Sensor Actuated Irrigation Control System

        This is a system level view that shows how Irrigate7, RPUpi, HT, MT, LT, and PT are used.
        Work is in Progress (some parts will soon need alpha testers... see status images bellow)
        

         
        If you want to evaluate a Solar Charge Controler contact me, 
        they are not in a store. 
        
        
          
        Shields with RS-422 RX and TX full duplex communication and 
        a RS-485 half duplex out of band management channel. 


        
        General purpose evaluation board with built-in solar charge 
        controller. I am using it to prove ideas and firmware befor 
        building the more expensive boards (like Irrigate7 and 
        PulseDAQ), ^4 will have some pluggable connectors for 
        five digital IO with level conversion, two analog loops, and a
        pulse capture input for flow meters or pulse output sensors.
        
        
          
        
        These boards transmit current loop events (Pulse) through a CAT5 
        pair. They include Capacitive Sensors with Thermistors [HMLP]T, OneShot,
        and Variable Reluctance (the center of a sensed body).  See 
        RPUno ^4 to see how to interface with MCU's ICPx input(s).


        
        ATMega1284P application Board with eight selectable Pulse (current loop 
        type) inputs used to measure sensors on CAT5 pairs. Flow pulse input. 
        Seven latching solenoids drivers (9/12/24V selectable). Five general 
        purpose I/O. This needs 


        For sale? some alpha units are available if you call. It is MOSTLY open 
        hardware so you should be able to make your own, but the designs are 
        in flux, and errors are included for free. Near the bottom of each board 
        page is a change log with links to the Mercurial repository where you 
        can fish through the board assembly files. They may change or even 
        be removed at my option (e.g. found a better way or...) without any 
        sort of notice.

        Note for the DIY types that want through hole parts, I'm not 
        interested in your bad eyes or shaking hands since I have my own 
        thank you. I still find the toaster* oven is an easy way to make my 
        own boards and know for a fact that the ceramic capacitors don't 
        get thermal shocked by my soldering iron (ceramic capacitors can 
        work decades, but once a thermal shock fracture is present failure 
        is inevitable within days, weeks or months)
        
        *       https://github.com/epccs/RPUno/tree/master/Reflow


        

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Copyright (C) 2016 Ronald Steven Sutherland

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(Donation: $0.00 from 8/14 to 5/16).