examples: further work on at-lora

Signed-off-by: deadprogram <ron@hybridgroup.com>

examples/lora/atcmd/sim.go

@@ -3,6 +3,28 @@
 package main
 
 // do simulator setup here
-func setup() error {
-	return nil	
+func setupLora() (LoraRadio, error) {
+	return &SimLoraRadio{}, nil	
 }
+
+type SimLoraRadio struct {
+}
+
+func (sr *SimLoraRadio) Reset() error {
+	return nil
+}
+
+func (sr *SimLoraRadio) LoraTx(pkt []uint8, timeoutMs uint32) error {
+	return nil
+}
+
+func (sr *SimLoraRadio) LoraRx(timeoutMs uint32) ([]uint8, error) {
+	return nil, nil
+}
+
+func (sr *SimLoraRadio) SetLoraFrequency(freq uint32) {}
+func (sr *SimLoraRadio) SetLoraIqMode(mode uint8) {}
+func (sr *SimLoraRadio) SetLoraCodingRate(cr uint8) {}
+func (sr *SimLoraRadio) SetLoraBandwidth(bw uint8) {}
+func (sr *SimLoraRadio) SetLoraCrc(enable bool) {}
+func (sr *SimLoraRadio) SetLoraSpreadingFactor(sf uint8) {}