refactoring using async/await and new interrupt class code based on pigpio. Handler keeps proper scope. Interrupts working!!!

lib/mcp23008-17.js

@@ -44,14 +44,27 @@ class MCP23008 extends Device {
   }
 
   async start() {
-    console.log(`begin starting ${ this.id }`)
+    // console.log(`starting ${ this.id }`)
     for (let port in this.ports) {
+      // if there are interrupts being used then start them and listeners
       if (this.inter(port)) {
+        await this.interruptReset(port)
+        await this.inter(port).start()
+          // bind handler to the chip to handler can read/write to chip/bank when interrupt is emitted
+        let ihandler = this.inter(port).handler.bind(this)
+          // inside the listener `this` is the interrupt not the chip/bank
+        this.inter(port).on('fired', function () {
+          console.log(`interrupt from ${this.pin_number}`)
+          ihandler(port)
+        })
+      }
+    }
+  }
+
+  async interruptReset(port = 'A') {
     await this.read(portReg(0x08, port))
-        await pause(200) // give enough time for mcp to reset its interupt
+    await pause(300) // give enough time for mcp to reset its interupt
-        this.inter(port).start()
+    console.log(`interrupt reset on ${this.id} port ${port}`)
-      }
-    }
   }
 
   // start() {
@@ -82,6 +95,10 @@ class MCP23008 extends Device {
   //   return Promise.all(starts)
   // }
 
+  portByInterPin(pin) {
+    return 'A'
+  }
+
   pin(id) { return this.ports.A.pin(id) } // get a reference to a particular pin's object
 
   pid(address) { return this.ports.A.pid(address) } // return pin id for a given address on a port
@@ -222,6 +239,12 @@ class MCP23017 extends MCP23008 {
     return this.ports[port].pid(address)
   }
 
+  portByInterPin(pin) {
+    if (this.ports.A.interrupt.pin_number === pin) { return 'A' }
+    if (this.ports.B.interrupt.pin_number === pin) { return 'B' }
+    return false
+  }
+
   portByPin(id) {
     console.log('pin id in portbypin', id)
     if (this.ports.A.pin(id)) { return 'A' }