[chbot] Next Robotics meeting, 17th Sept 2018 : ARM special

[Volker Kuhlmann]

On Mon 03 Sep 2018 13:08:36 NZST +1200, Stephen Irons wrote:

> Make before break on the slide switch, connecting either power or
> ground to the I/O pin that was driving the other way?

The key words here are "make before break". With a MOSFET I thought I
should get away with a very simple circuit, connected the switch centre
to the MOSFET gate, and the 3 switch positions to 5V, I/O pin, GND.
Because I don't have output pin control working yet I connected the
switch terminal meant for the I/O pin to 3.3V to see if (5 - 3.3)V
exceeds the gate threshold voltage (it does). Operating the switch then
temporarily shorted 5V with 3.3V on the RPi pin header... and the new 5V
2.5A RPi plug packs give enough uumph to cause some real problem!

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.