@GoranLundberg I reviewed your PR! Brace yourself, tons of comments :)
hehe, expected that. Like I said. The test remake is basically a proof of concept to see if you'd like it. Its not exactly finished. Needs polishing. The MCP23017 code should be complete though, unless you find some issues.
A question. Do you want me to add MCP23018 as a separate supported device?
The MCP23018 is 100% compatible with 17, only different electronically (can tolerate 5v when powered by 3.3v which the 17 can't). You can initiate it like the 17 and will work perfectly. But I see a good reason to add it as a separate device. When working on a project its easier to see MCP23018 in the code.. Especially if you have one 17 and one 18. Easier to see which one is which in the code. The code is exactly the same, just need to add it as an alias of the 17.
The MCP23018 is 100% compatible with 17, only different electronically (can tolerate 5v when powered by 3.3v which the 17 can't). You can initiate it like the 17 and will work perfectly. But I see a good reason to add it as a separate device. When working on a project its easier to see MCP23018 in the code.. Especially if you have one 17 and one 18. Easier to see which one is which in the code. The code is exactly the same, just need to add it as an alias of the 17.
Are you familiar with feature branches in git?
this might help: https://www.atlassian.com/git/tutorials/using-branches
it's good practice to create a new branch for every feature or fix, then they can be handled independently.
also, it allows you to update your master to the same state as upstream master without affecting any of your commits.
Adding it as an example in the tests.
Makes it easy to copy paste.
0x27
Also the name of the test directory "lcdtests" should maybe be renamed to "lcdtest-modules" or similar. Any ideas?
Also, what about "show_charmap" and "testsuite"?
Testsuite works!
Also, I think that test name maybe should go before i2c/gpio.
lcdtest.py show_charmap i2c expander=MCP23017......
I think the numbering mode should go before the pins though.
(in the examples)
we can always improve later :)
Sorry about the 'all fixes in one' pull request. Will try to make a new PR for each in the future.
@GoranLundberg - using a level shifter is the correct and safest way! But I have done some short test the way you said and also by providing 3.3V instead of 5V (display won't look really good and you need to adjust contrast) whis is safer for the Pi. Also on Adafruit MCP23008 I cut the power pin from MCP to add 2 x 1N4148 diodes between 5V rail and MCP power pin and I removed the pull-up's on I2C from the backpack.