I have a MCP23009 IC that I want to use as out put. So far so good, I used it once before as input and the ..17 as output, but...
I get a strange result. The LEDs will blink, but only if I connect them anode/plus to the V+ and cathode/minus to the mcp pin
This is the source:
#include <Wire.h>
#include "MCP23009.h"
// Basic toggle test for i/o expansion. flips pin #0 of a MCP23009 i2c
// pin expander up and down. Public domain
// Connect pin #1 of the expander to Analog 5 (i2c clock)
// Connect pin #2 of the expander to Analog 4 (i2c data)
// Connect pins #3, 4 and 5 of the expander to ground (address selection)
// Connect pin #6 and 18 of the expander to 5V (power and reset disable)
// Connect pin #9 of the expander to ground (common ground)
// Output #0 is on pin 10 so connect an LED or whatever from that to ground
// Note, based on MCP23009, but I modified it a bit
// (lib was originally made for mcp23008
// that code checks for addresses < 7 and my mcp has the address pin connected to 5V (and so has address 0x27)
MCP23009 mcp;
void setup() {
mcp.begin(0x27); // use default address 0
for (int i=0; i< 8; i++)
mcp.pinMode(i, OUTPUT);
}
// werkt wel, maar soms omgekeerd (dus de OUTPUT als GND?!)
// flip the pin #0 up and down
void loop() {
for (int i=0; i< 8; i++) {
//mcp.pinMode(i, OUTPUT);
delay(1000);
mcp.digitalWrite(i, HIGH);
delay(1000);
mcp.digitalWrite(i, LOW);
}
}
