LeafLabs Garden

A place to share, learn, and grow...

1. 

   crenn
   Moderator

   Thought I'd share this code here while I work on the library in case people wish to see what I'm working on. I've written a little light chaser program, just it's not using the Maple's GPIO, it's using a single 8-bit GPIO register of the MCP23018. I got the chips this morning from Microchips Sample Program (I'm planning for QFN versions these chips to be used in a project in the future) and decided to get working on making a driver for them. After some initial problems (reading the reference manual incorrectly) I've finally made a working driver, and used a 'simple' light chaser example to display it.

   The code is available here:
   http://www.crennsmind.com/Code/Maple/PortExpand/MCP23x18_driver.txt

   And a video demonstration is available here:
   http://www.youtube.com/watch?v=18b01mdbTaM

   I'd also like to mention the library for this chip will also support the SPI version (MCP23S18) as well as the code used to communicate with them is near identical. Additionally, I'll be making a library for users of ATMEGA/ATTINY devices having trouble wrapping their heads around the STM32F1 GPIO some help which will provide an opportunity to learn how to as well as a simple interface. It could technically be used in place where there is a ATMega device library that directly accesses the GPIO.

   Posted 3 years ago #
2. 

   mbolivar
   LeafLabs

   cool! care to submit a patch to the libmaple examples/ directory for this code?

   Posted 3 years ago #
3. 

   crenn
   Moderator

   How about I do the impossible and do a pull request? ;D I'll comment the code today before I do that.

   Posted 3 years ago #
4. 

   crenn
   Moderator

   Taken some time, but I completed a driver last night (technically last night now) to drive both the MCP23018 and the MCP23S18. The code still needs to be commented, but it will allow code like this:

   


   mcp.IOCON = 0x0000;
mcp.IODIR = 0x0000;
mcp.GPPU = 0xFFFF;
SerialUSB.println(mcp.GPPU, HEX);

   There is also a few more operators needed to implement, but should work quite well making it easy to manipulate the registers on the MCP23x18.

   Posted 2 years ago #
5. 

   crenn
   Moderator

   I've released the library now and I'll be doing a few more touches on it like adding support for ^= <<=, etc.

   You can get the library from here:
   http://github.com/crenn/MCP23x18

   Posted 2 years ago #

RSS feed for this topic

Reply

You must log in to post.