Mcp 23017 and Pic 16f877

[Acetronics2]

Hi, Claudy

Following your adventures on many forums for a moment ... I still miss a small thing : YOUR USED SCHEME ...

Alain

[CLAUDY]

Hello Alain,

I still have not found the solution.

Here's a quick diagram as requested.Printing TEST MCP23017-sch.pdf

Thank you

Claudy

[Acetronics2]

Looks there's also a missing register named IOCON in the settings.

Alain

[CLAUDY]

Hello everyone,

Ok it works!

Bit 7 of Port A and B of the MCP23017 must be 1 before the startup of the program.

And in this case each power program is operating normally the first

Here is the code added.

i2cwrite sda,scl,$40,[iolata,128] 'Output Latch Reg
i2cwrite sda,scl,$40,[iolatb,128] 'Output Latch Reg


If you have comments please.

Thank you

Claudy

[rauloj]

Bit 7 of Port A and B of the MCP23017 must be 1 before the startup of the program.

And in this case each power program is operating normally the first

Here is the code added.

i2cwrite sda,scl,$40,[iolata,128] 'Output Latch Reg
i2cwrite sda,scl,$40,[iolatb,128] 'Output Latch Reg


If you have comments please.

Thank you

Claudy

Hi Claudy!

It's not OLATA/OLATB you are setting 1, but IOCON.
After power-on BANK bit = 0 and IOCON's adr = 0A/0B not OLATA/OLATB's.
After setting IOCON bit 7 to 1 you can use address mapping as described in datasheet table 1-5.

R