Right, makes sense. Running it at 5V with the I2C operating at 3.3v was one of the main reasons why I rejigged my hardware project to use an MCP23017, meant I could ditch a whole load of level firstname.lastname@example.org wrote:Less chance of doing something silly and blowing up a Pi...Sonny_Jim wrote:Just curious, why the recommendation to run the mcp23017 at 3.3v rather than 5v? I run mine at 5V with seemingly no problems.
To get back on topic, a couple of questions:
1. With wiringPi, how can I change the I2C speed?
2. Gordon, do you have any plans to update wiringPi so the MCP23017 can be loaded up with data faster, rather than a bit at a time?
3. Could someone give me an example of when I would want to use the MCP23017 interrupts? Looks to me that it's only handy in keyboard/input matrixes, you just monitor one pin for a change rather than all 8/16 of them.