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-------------------------------------------------------------------------------
Microchip MCP23017 I/O expander with I2C interface
-------------------------------------------------------------------------------
This is a set of example captures of the MCP23017 16-bit I/O expander with
an I2C interface. For details see the MCP23017/MCP23S17 datasheet which is
titled "16-Bit I/O Expander with Serial Interface":
http://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf
Logic analyzer setup
--------------------
The logic analyzer used was a Saleae clone (samplerate 1MHz). In addition
to the I2C datalines, 6 output pins are captured too.
The host was a Raspberry Pi using Python to access the I2C port. The bitrate
decreased after a few 100ms.
Probe MCP23017
-------------------
0 A0
1 A1
2 A2
3 B0 / A3
4 B1 / A4
5 B2 / A5
6 SDA
7 SCL
mcp23017_counter_a_write.sr
---------------------------
Count the Registers OLATA ascending. The lowest 6 bits of the Output A Port
are captured too (A0 - A5).
mcp23017_counter_init_ab_write.sr
---------------------------------
Reset all registers, then count the registers OLATA ascending and OLATB
descending. Both registers are set using one word write operation. The
lowest 3 bits of both output ports are captured too (A0 - A2, B0 - B2).
mcp23017_counter_init_ab_write_read.sr
-------------------------------------
Reset all registers, then count the registers OLATA ascending and OLATB
descending. Both registers are set and read using one word write operations.
The lowest 3 bits of both output ports are captured too (A0 - A2, B0 - B2).
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