antplusbridge/cmd/bridge/ant.go
2026-06-14 14:58:22 +02:00

99 lines
2.3 KiB
Go

package main
import (
"context"
"io"
"time"
"github.com/google/gousb"
"github.com/half2me/antgo/ant"
"github.com/half2me/antgo/device"
"github.com/half2me/antgo/driver/usb"
)
const (
antDataPageMask = 0x7F // Mask for data page number (7 bits, clears toggle bit)
antDataPageCyclingPower = 0x10 // Data page 16 = Cycling Power Feature page
)
func resetAndWait(drv io.ReadWriter) error {
if _, err := drv.Write(ant.SystemResetMessage()); err != nil {
return err
}
// drain until we see the startup message (0x6F)
for {
msg, err := ant.ReadMsg(drv)
if err != nil {
return err
}
if msg.Class() == ant.MESSAGE_STARTUP {
return nil
}
}
}
func ListenForTrainer(vendorId uint16, productId uint16, deviceNumber uint32,
events chan<- Event) {
drv, err := usb.GetDevice(gousb.ID(vendorId), gousb.ID(productId))
if err != nil {
panic(err)
}
defer drv.Close()
logMsg("ant: device opened")
if err := resetAndWait(drv); err != nil {
panic(err)
}
if err := device.StartRxScanModeWait(drv); err != nil {
panic(err)
}
logMsg("ant: scan mode started")
msgs := make(chan ant.BroadcastMessage, 100)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
go func() {
device.DumpBroadcastMessages(ctx, drv, msgs)
logMsg("ant: dump broadcast messages ended")
}()
logMsg("ant: listening...")
for {
select {
case msg := <-msgs:
if deviceNumber != 0 && msg.DeviceNumber() != deviceNumber {
logPrintf("ant: received msg from ignored device %v\n", msg.DeviceNumber())
continue
}
//fmt.Printf("raw msg: device type=0x%02x device number=%d content=%x\n",
// msg.DeviceType(), msg.DeviceNumber(), msg.Content())
switch msg.DeviceType() {
case ant.DEVICE_TYPE_POWER:
// Check data page first
page := msg[4] & antDataPageMask
if page != antDataPageCyclingPower {
continue
}
cur := ant.PowerMessage(msg)
logPrintf("ant: %v: power: %dW cadence: %d rpm\n",
msg.DeviceNumber(), cur.InstantaneousPower(), cur.InstantaneousCadence())
select {
case events <- Event{
Power: cur.InstantaneousPower(),
Cadence: cur.InstantaneousCadence(),
Now: time.Now(),
}:
default:
logPrintf("ant: dropped event, buffer full\n")
}
}
case <-time.After(10 * time.Second):
logMsg("ant: no more messages arrived, restarting")
return
}
}
}