fixed multiple MIDI devices S/N

hardware/OS2LDriver.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"math/rand"
+	"strings"
 )
 
 // OS2LDriver represents how the protocol is defined
@@ -27,7 +28,7 @@ func (d *OS2LDriver) Initialize() error {
 // CreatePeripheral creates a new OS2L peripheral
 func (d *OS2LDriver) CreatePeripheral(ctx context.Context) (Peripheral, error) {
 	// Create a random serial number for this peripheral
-	randomSerialNumber := fmt.Sprintf("%08x", rand.Intn(1<<32))
+	randomSerialNumber := strings.ToUpper(fmt.Sprintf("%08x", rand.Intn(1<<32)))
 	peripheral := NewOS2LPeripheral("OS2L", randomSerialNumber)
 	d.peripherals[randomSerialNumber] = peripheral
 	return peripheral, nil