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.
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).
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.
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
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).
Market Place: Opencart[*] or Tindie [**] (not sure yet). * http://www.opencart.com/ ** https://www.tindie.com/
"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 GitHub
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.
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
Copyright (C) 2016 Ronald Steven Sutherland
(Donation: $0.00 from 8/14 to 5/16).