4 ms·

Setting pin high or low can get you in conflict with other devices connected to that pin. In the best case you wouldn't tell which pin is which and in the worst

• anoonmoose 11y ago
  This is an excellent point, one that I overlooked because I am usually testing devices in isolation from the systems that they are a part of. EXTEST would probably work well in a situation more like the Arduino example from the slides, where the board is more of a breakout for a chip rather than the chip being part of a bigger system. Edit: although, since he's using a wire and pushbutton to apply 3.3V to different pins, wouldn't he have the same problem you're suggesting I have?
  • VLM 11y ago
    He doesn't mention it directly but if you look at the pix you can see a resistor inline and he kinda tangentially mentions limiting current to prevent disaster. I suggest throwing a LED in series too, when it lights up you've found yourself a ground pin. Look for fun with pull-up resistors, sometimes you'll need to pull up and down. I2C with pullups on both pins unless you have active termination comes to mind. So throw another pull up in parallel with the existing hardware, nothing happens, hmm... Sometimes you're gonna want to pull down thru a resistor too.