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Topic: Figuring out which pins are available (Read 146 times) previous topic - next topic


Jul 22, 2018, 04:53 pm Last Edit: Jul 22, 2018, 04:54 pm by davepl
So I wasted half a day on a ESP32 project I'm tinkering with because I moved from a Node32S to a Heltec WiFi unit.  They're both ESP32-WROOM chips but I think the Heltec's built-in OLED must have been competing with the pins I was trying to use.

But on the Node32S version?  Works great, which is maddening, because it's not documented anywhere that I can find.

When dealing with a chip board or even an Arduino that has a shield, how do you go about determining which pins are free for use?  I mean I can look at the datasheet, and it shows pin 18 as a GPIO.  That means I should be able to use it... but no.


the oled is i2C. http://www.heltec.cn/download/WIFI_Kit_32-Diagram.pdf
You can't write an Arduino sketch if you didn't learn programming. Not the language, but the concepts of programming - algorithms and data types.


Hope for some documentation. In a perfect world there would be a clear table of the pins used. Failing that, often a schematic is provided. Failing that, you need to try to figure it out from the hardware. It can be helpful to understand the communication protocol. For example, if you have an Ethernet shield and you know the Ethernet controller chip uses SPI then you can be sure it's connected to the SPI pins on the Arduino board. Then you only need to figure out which CS pin it uses. The software needs to know this so you could figure it out by looking at the code.


Someone posted on the forum a while back about how it was outdated and abandoned and how they were planning to start a new project and wanted volunteers and input. I responded with some ideas and an offer to help and they never even responded. I guess with that sort of follow through it was best to not have wasted any time trying to work with them anyway.

I noticed is that shieldlist.org hasn't been updated for 5 years now, has a backlog of 531 submissions

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