Project – two wheel Bot based on design by Stewart Watkiss / Penguin Tutor
Greetings Pi Community,
I have been spinning my wheels for days (no pun intended – well maybe) reading everything I could find on how to wire-up the Pi, motors with encoders, motor drivers and make everything work with PIGPIO and I have failed to see the way forward.
Therefore, any advice or guidance the community can provide to help me move forward with is project would be greatly appreciated.
Project details:
Current Project Stage - GPIO buffering with goal of constructing two (2) Pi-hats to mount buffering devices and input-output terminal blocks for all non-power GPIO pins.
Bot power:
>5V-3A PS supplied by 7V2 battery pack - design MagPi issue 6 John Ellerington
>DC motors use separate 6V battery pack
Project mobility code and items in-hand:
>PWM managed by PIGPIO to control the bot
>RPi A+
>Pololu 75:1 25Dx54L mm with 48 CPR Encoder part # 2275
>Pololu VNH5019 motor drivers part # 1451
>Adafruit Perma-Proto board HAT for Pi
>4N25 opto-couplers
>SN7407N shift leveler
Advice and recommendations requested on:
> GPIO pin selection and isolating device recommended for use with PID (only plan on using PD)
> GPIO pin selection and isolating device recommended for use with future bot input-output activities e.g. using I2C, interfacing with analog devices, etc.
> Circuit design for output/input isolation using a combination of opto-isolators and shift leveler with the goal of isolating the Pi from all potential electrical mishaps (I know this maybe excessive – but it is fun and I am learning)
> Sorting out how ground connections fit into providing electrical isolation for the Pi
Thank you for taking the time to read this post and for any suggestions you my share.
Cheers,