add barebones

sx127x/barebones.go

@@ -0,0 +1,112 @@
+package sx127x
+
+import (
+	"errors"
+
+	"github.com/soypat/lora"
+)
+
+type DeviceLoRaBare struct {
+	DL DeviceLoRa
+}
+
+func (d *DeviceLoRaBare) Configure(c lora.Config) (err error) {
+	err = d.DL.InitLoRaMode()
+	if err != nil {
+		return err
+	}
+	err = d.DL.SetOpMode(OpSleep)
+	if err != nil {
+		return err
+	}
+	// Set up FIFO
+	// We configure so that we can use the entire 256 byte FIFO for either receive
+	// or transmit, but not both at the same time
+	d.DL.Write8(regFIFO_TX_BASE_ADDR, 0)
+	d.DL.Write8(regFIFO_RX_BASE_ADDR, 0)
+
+	// Bw125Cr45Sf128
+	d.DL.Write8(regMODEM_CONFIG_1, 0x72)
+	d.DL.Write8(regMODEM_CONFIG_2, 0x74)
+	d.DL.Write8(regMODEM_CONFIG_3, 0x00)
+
+	d.DL.setPreambleLength(8)
+	d.DL.setFrequency(lora.Freq169_4M)
+	return d.crappySetTxPower(13, false)
+}
+
+func (d *DeviceLoRaBare) crappySetTxPower(power int8, useRFO bool) (err error) {
+	if useRFO {
+		if power > 14 {
+			power = 14
+		} else if power < -1 {
+			power = -1
+		}
+		err = d.DL.Write8(regPA_CONFIG, 0x70|uint8(power+1))
+	} else {
+		if power > 23 {
+			power = 23
+		} else {
+			power = 5
+		}
+		// For RH_RF95_PA_DAC_ENABLE, manual says '+20dBm on PA_BOOST when OutputPower=0xf'
+		// RH_RF95_PA_DAC_ENABLE actually adds about 3dBm to all power levels. We will us it
+		// for 21, 22 and 23dBm
+		if power > 20 {
+			d.DL.Write8(regPA_DAC, 0x07)
+			power -= 3
+		} else {
+			d.DL.Write8(regPA_DAC, 0x04)
+		}
+		// RFM95/96/97/98 does not have RFO pins connected to anything. Only PA_BOOST
+		// pin is connected, so must use PA_BOOST
+		// Pout = 2 + OutputPower.
+		// The documentation is pretty confusing on this topic: PaSelect says the max power is 20dBm,
+		// but OutputPower claims it would be 17dBm.
+		const paSelect = 0x80
+		err = d.DL.Write8(regPA_CONFIG, paSelect|uint8(power-5))
+	}
+	return err
+}
+
+func (d *DeviceLoRaBare) Send(packet []byte) (err error) {
+	if len(packet) > 251 {
+		return errors.New("too long")
+	}
+	gotmode, err := d.DL.GetOpMode()
+	if err != nil {
+		return err
+	}
+	if gotmode != OpStandby && gotmode != OpSleep {
+		return errors.New("not in standby or sleep before Tx")
+	}
+	err = d.DL.SetOpMode(OpStandby)
+	if err != nil {
+		return err
+	}
+	// Position at the beginning of the FIFO.
+	d.DL.Write8(regFIFO_ADDR_PTR, 0)
+	for i := range packet {
+		d.DL.Write8(regFIFO, packet[i])
+	}
+	d.DL.Write8(regPAYLOAD_LENGTH, uint8(len(packet)))
+	err = d.DL.SetOpMode(OpTx)
+	if err != nil {
+		return err
+	}
+	return d.DL.SetIRQTxDoneOnDIO0()
+}
+
+func (d *DeviceLoRaBare) HandleInterrupt() {
+	flags, _ := d.DL.read8(regIRQ_FLAGS)
+	if flags != 0 {
+		println("got irqs:", irqFlagsString(flags))
+	}
+	// Clear flags
+	d.DL.Write8(regIRQ_FLAGS, 0xff)
+}
+
+func (d *DeviceLoRaBare) Read(addr uint8) uint8 {
+	val, _ := d.DL.read8(addr)
+	return val
+}