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• WHAT IS UP HACKADAY !? ITS BEEN A WHILE LETS UPDATE

  AVR • 08/02/2023 at 18:13 • 0 comments

  This project has sat on the backburner for quite sometime but I have been thinking about it alot over the last few months and in the last couple of days I have completely overhauled my approach and developed a complete electrical system architecture for an open source wheel chair. We are going to prototype this system and graft it to an existing wheelchair owned and operated by our fearless leader Tom !
  

  A Block Diagram says a thousand words as I've always said, so here we go !! Here is the overall architecture of the system !!
  

  To begin with an electric wheelchair electrical system isn't super complicated to begin with in terms of the physical hardware (custom safety rated firmware for all the embedded devices in the system is the biggest challenge), I distilled down the group discussions we have been having amongst our team and boiled it down to the architecture in the diagram.
  You will notice that the biggest change there is no mention of the USB HID Black box device I was originally going to develop, I decided that I still want to do that, but I would rather make a custom Joystick shield for the Raspberry Pi that has the Joystick module and all the other controls/indicators the wheelchair user will need to operate their chair but also have the ability to interface with any USB HID device at the same time. This will allow use to build a traditional electric wheel chair control interface, but also allow us to audition and test many other off the shelf devices and explore what we can do with them for potential users. This is effectively going to be a complicated research platform in its first iteration and as we go I hope to develop it down into a completely integrated, robust, fully embedded RTOS based system with no Linux SoC require.

  The overall architecture hinges on two pieces of custom hardware, and the rest are off the shelf components. A cool guy named James is designing a custom motor controller that will be able to driver all the different motors in the chair from a single PCB. The other piece of custom hardware is the Joystick/USB HID Wheelchair controller research platform, an RPi Hat that contains all the standard wheelchair controls, with the RPi being used for USB interfacing and Bluetooth interfacing.  The Joystick Hat will communicate with the Motor controller via RS485, the motor controller will also function as the power distribution board and send the bus voltage to the Joystick, the Hat board will have an integrated PSU to step down the bus voltage for all onboard devices.  The two off the shelf devices are the massive LifePoE battery with built in BMS, and the Bluetooth shunt used for monitoring and tracking the battery performance since it doesn't have any way for the BMS to report data to us.
  

  Moving on to the main attraction !! I am designing the Joystick /USB HID hat! Like I said before and I will say it again, block diagram is worth 1000 words:
  

  Basic Feature set:

  - Classic Wheel Chair Joystick
  

  - Dual Speed switch

  - Variable speed switch (for fine tuning of speed)
  - LED indicator for power/power level
  - LED Indicator for Set speed
  - USB configuration port, so the user can adjust all the operational parameters to their unique preferences/needs
  - Optional Horn control
  

  To make all this work I am designing a custom Hat PCB for the RPi, here is the block diagram and tech specs so far:

  
  Tech Specs:
  - RPi 3
  - STM32F446RET6 ARM Cortex M4F MCU
  

  -  JH-D202X-R2/R4 5K 10K Joystick module
  

  - Ti DCDC Converters
  - Switchcraft Mechanical Switches

  That's all for now !
  

• Colloborator: The Mobility Independence Foundation

  AVR • 05/20/2023 at 22:45 • 0 comments

  The Mobility Independence Foundation (MIF) is a non-profit organization dedicated to promoting and supporting mobility independence for individuals with disabilities. The foundation aims to enhance the quality of life and opportunities for people with disabilities by providing them with access to adaptive vehicles and mobility equipment. By doing so, MIF seeks to empower individuals to lead independent and fulfilling lives.

  https://themif.org/

  The MIF was founded by my friend Thomas Quiter and I was brought on to bring my robotics and hacking experience to their organization.  Please visit their website and learn about their organization, we will be doing amazing things together !!
  
  

• RPi and Python Lets Go

  AVR • 05/20/2023 at 22:38 • 1 comment

  To make things quick and dirty easy I am developing the blackbox around the RPI Zero Wireless !! The program will be in Python, it should be sufficiently fast for this application and it will be easy to interface with lots of USB and Bluetooth devices via open source libraries very easily !! I whipped up a python script super fast to start the concept on.
  
  

  Hardware:
  - RPi Zero Wireless

  - PSU

  - USB HMI Mouse

  - Header for RPi GPIO Pins

  Software:

  - https://github.com/adamjvr/py-rpi-hmi-pwm

  I need to dig through my piles of stuff to find where my RPi zeros are but I got a few to dedicate to this project !! Take a look at the code and give me your feedback, I've never written python before but I've programmed in other languages before.
  

• Individuals That Use Wheel Chairs We Need Your Thoughts and Opinions !

  AVR • 05/16/2023 at 15:33 • 1 comment

  Title says it all !! I myself am an able bodied person so I don't have the personal experience of living with a wheel chair or relying on accessibility technology. Which is why I want to hear from those who do and what they have to say, this project is open source and its meant to help as many people as possible so its important to get their voices heard and ideas integrated into the designs.

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