SparkFun Forums

[A13]

As far as i understood it the GPIOs can be set to have certian interfaces on the Pads of Artemis, my question now is how these settings can be adjusted to the needs. Is this possible via the arduino Core or in any other way?

[stephenf]

Are you talking about the ability to control pin drive strength and the like? There was a post explaining this some way back. In the cores up to 1.2.1 this was possible through HAL functions - find the definitions of pinMode in the code for that version on Github and follow it to the possibilities. It's unclear what's happened to this functionality in cores 2.x.x

[Nickell]

The Artemis module has 48 interrupt capable GPIO pads and a slew of Checkout the pin function map, the Apollo3 datasheet, and the 2, 4, 8, or 12mA can be selected as the max current on a given pin.

[mariasbarker]

Try accessing the GPIOs via sysfs through the package dey-examples-gpio-sysfs

[paulvha]

Recently I wrote a library + examples that allows you to set different modes for the GPIO's. You can select as output with different drive-strengths, or as input with different pull-ups or use the power switch mode on some pins (either VDD or VSS) to switch on/off a sensor. Maybe it helps you https://github.com/paulvha/apollo3/tree/master/APgpio. It works on both 1.2.1 and 2.X.X

[RusselGlover]

I have built a scrolling LED matrix using an ESP-01 module as the brains. A factory reset switch is required so that the WiFi credentials can be reset easily, so what I have done is shared GPIO3 (the RX pin) between the chip select of the MAX7219 module and the reset button. At startup the pin is set as an input with pullup, and if the pin is low a function is called that resets the wifi information. If it is high the pin is set as an output and the program carries on.

I have used a 2.2k resistor to ground, so that when it is pulled low it isn't a dead short if the button is pressed during normal operation.

I have tested this, and it does work without interfering with the MAX7219 display, but is this an acceptable bodge? Is it safe? Is there a chance that this could bite me down the line?