firmata: addition of support for firmata protocol

bmxx80/bmxx80.go

@@ -20,6 +20,9 @@ import (
 	"periph.io/x/conn/v3/spi"
 )
 
+// I2CAddr i2c default address.
+const I2CAddr uint16 = 0x77
+
 // Oversampling affects how much time is taken to measure each of temperature,
 // pressure and humidity.
 //

firmata/analog_mapping.go

@@ -0,0 +1,43 @@
+package firmata
+
+import (
+	"bytes"
+	"fmt"
+)
+
+type AnalogMappingResponse struct {
+	AnalogPinToDigital []uint8
+	DigitalPinToAnalog map[uint8]uint8
+}
+
+func ParseAnalogMappingResponse(data []byte) AnalogMappingResponse {
+	var response = AnalogMappingResponse{
+		AnalogPinToDigital: []uint8{},
+		DigitalPinToAnalog: map[uint8]uint8{},
+	}
+
+	for i := 0; i < len(data); i++ {
+		if data[i] != CapabilityResponsePinDelimiter {
+			response.DigitalPinToAnalog[uint8(i)] = uint8(len(response.AnalogPinToDigital))
+			response.AnalogPinToDigital = append(response.AnalogPinToDigital, uint8(i))
+		}
+	}
+
+	return response
+}
+
+func (a AnalogMappingResponse) String() string {
+	str := bytes.Buffer{}
+	for analogPin, digitalPin := range a.AnalogPinToDigital {
+		_, _ = fmt.Fprintf(&str, "A%d: %d\n", analogPin, digitalPin)
+	}
+	return str.String()
+}
+
+type ExtendedAnalogMappingResponse struct {
+	Pin uint8
+}
+
+func (a ExtendedAnalogMappingResponse) String() string {
+	return fmt.Sprintf("%d", a.Pin)
+}

firmata/capability.go

@@ -0,0 +1,75 @@
+package firmata
+
+import (
+	"bytes"
+	"fmt"
+
+	"periph.io/x/conn/v3/pin"
+)
+
+var pinModeOrder = []pin.Func{
+	PinFuncDigitalInput,
+	PinFuncDigitalOutput,
+	PinFuncAnalogInput,
+	PinFuncPWM,
+	PinFuncServo,
+	PinFuncShift,
+	PinFuncI2C,
+	PinFuncOneWire,
+	PinFuncStepper,
+	PinFuncEncoder,
+	PinFuncSerial,
+	PinFuncInputPullUp,
+	PinFuncSPI,
+	PinFuncSonar,
+	PinFuncTone,
+	PinFuncDHT,
+}
+
+const CapabilityResponsePinDelimiter = 0x7F
+
+type CapabilityResponse struct {
+	PinToModeToResolution []map[pin.Func]uint8
+	SupportedPinModes     [][]pin.Func
+}
+
+func ParseCapabilityResponse(data []byte) CapabilityResponse {
+	var response = CapabilityResponse{
+		PinToModeToResolution: []map[pin.Func]uint8{{}},
+		SupportedPinModes:     [][]pin.Func{{}},
+	}
+
+	var pindex = 0
+	for i := 0; i < len(data); {
+		if data[i] == CapabilityResponsePinDelimiter {
+			response.PinToModeToResolution = append(response.PinToModeToResolution, map[pin.Func]uint8{})
+			response.SupportedPinModes = append(response.SupportedPinModes, []pin.Func{})
+			i += 1
+			pindex++
+		} else {
+			pinFunc := pinModeToFuncMap[data[i]]
+			response.PinToModeToResolution[pindex][pinFunc] = data[i+1]
+			response.SupportedPinModes[pindex] = append(response.SupportedPinModes[pindex], pinFunc)
+			i += 2
+		}
+	}
+
+	return response
+}
+
+func (c CapabilityResponse) String() string {
+	str := bytes.Buffer{}
+	for p, modeMap := range c.PinToModeToResolution {
+		_, _ = fmt.Fprintf(&str, "pin %2v: [", p)
+		if len(modeMap) > 0 {
+			for _, mode := range pinModeOrder {
+				if resolution, ok := modeMap[mode]; ok {
+					_, _ = fmt.Fprintf(&str, "%s: %d, ", mode, resolution)
+				}
+			}
+			str.Truncate(str.Len() - 2)
+		}
+		_, _ = fmt.Fprintf(&str, "]\n")
+	}
+	return str.String()
+}