commit 46cf56767e230de977354ecb3a5505af3915356e Author: Steven Polley Date: Sat Jul 1 10:16:12 2023 -0600 initial commit diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..93baa45 --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +env.sh \ No newline at end of file diff --git a/README.md b/README.md new file mode 100644 index 0000000..a8a97c1 --- /dev/null +++ b/README.md @@ -0,0 +1,3 @@ +# embedded-bt-rssi-monitor + +A bluetooth RSSI monitor to run on a tiny system such as a microcontroller or single board computer. \ No newline at end of file diff --git a/go.mod b/go.mod new file mode 100644 index 0000000..0fa513f --- /dev/null +++ b/go.mod @@ -0,0 +1,16 @@ +module deadbeef.codes/steven/embedded-bt-rssi-monitor + +go 1.20 + +require tinygo.org/x/bluetooth v0.7.0 + +require ( + github.com/fatih/structs v1.1.0 // indirect + github.com/go-ole/go-ole v1.2.6 // indirect + github.com/godbus/dbus/v5 v5.0.3 // indirect + github.com/muka/go-bluetooth v0.0.0-20220830075246-0746e3a1ea53 // indirect + github.com/saltosystems/winrt-go v0.0.0-20230510070731-e096b9afa761 // indirect + github.com/sirupsen/logrus v1.9.0 // indirect + github.com/tinygo-org/cbgo v0.0.4 // indirect + golang.org/x/sys v0.0.0-20220829200755-d48e67d00261 // indirect +) diff --git a/go.sum b/go.sum new file mode 100644 index 0000000..ec7eaab --- /dev/null +++ b/go.sum @@ -0,0 +1,119 @@ +github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU= +github.com/bgould/http v0.0.0-20190627042742-d268792bdee7/go.mod h1:BTqvVegvwifopl4KTEDth6Zezs9eR+lCWhvGKvkxJHE= +github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c= +github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= +github.com/eclipse/paho.mqtt.golang v1.2.0/go.mod h1:H9keYFcgq3Qr5OUJm/JZI/i6U7joQ8SYLhZwfeOo6Ts= +github.com/fatih/structs v1.1.0 h1:Q7juDM0QtcnhCpeyLGQKyg4TOIghuNXrkL32pHAUMxo= +github.com/fatih/structs v1.1.0/go.mod h1:9NiDSp5zOcgEDl+j00MP/WkGVPOlPRLejGD8Ga6PJ7M= +github.com/frankban/quicktest v1.10.2/go.mod h1:K+q6oSqb0W0Ininfk863uOk1lMy69l/P6txr3mVT54s= +github.com/glerchundi/subcommands v0.0.0-20181212083838-923a6ccb11f8/go.mod h1:r0g3O7Y5lrWXgDfcFBRgnAKzjmPgTzwoMC2ieB345FY= +github.com/go-kit/log v0.2.1/go.mod h1:NwTd00d/i8cPZ3xOwwiv2PO5MOcx78fFErGNcVmBjv0= +github.com/go-logfmt/logfmt v0.5.1/go.mod h1:WYhtIu8zTZfxdn5+rREduYbwxfcBr/Vr6KEVveWlfTs= +github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY= +github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0= +github.com/godbus/dbus/v5 v5.0.3 h1:ZqHaoEF7TBzh4jzPmqVhE/5A1z9of6orkAe5uHoAeME= +github.com/godbus/dbus/v5 v5.0.3/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA= +github.com/google/go-cmp v0.5.2/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE= 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h1:+TV5q0KpwSGRWnN+ITijsIhrWYJkoUCp9MYELjKpAXk= +tinygo.org/x/tinyfont v0.4.0/go.mod h1:7nVj3j3geqBoPDzpFukAhF1C8AP9YocMsZy0HSAcGCA= +tinygo.org/x/tinyfs v0.1.0/go.mod h1:ysc8Y92iHfhTXeyEM9+c7zviUQ4fN9UCFgSOFfMWv20= +tinygo.org/x/tinyterm v0.1.0/go.mod h1:/DDhNnGwNF2/tNgHywvyZuCGnbH3ov49Z/6e8LPLRR4= diff --git a/main.go b/main.go new file mode 100644 index 0000000..34ca81e --- /dev/null +++ b/main.go @@ -0,0 +1,151 @@ +package main + +import ( + "fmt" + "log" + "net/http" + "os" + "time" + + "tinygo.org/x/bluetooth" +) + +type MonitoredDevice struct { + MacAddress string + RssiHistory []int16 // RSSI readings over time. The latest is always last element: RssiHistory[len(RssiHistory)-1] + LastPing time.Time // Last time device was scanned +} + +const ( + rssiHistoryLength = 3 + pingTimeout = time.Second * 60 + // rssiThreshold int16 = -80 // anything lower doesn't count + + rssiThresholdLower int16 = -82 + rssiThresholdUpper int16 = -72 + terminalDashboardURL = "http://localhost:8080/set?screen=" +) + +var ( + adapter = bluetooth.DefaultAdapter + monitoredDevices []MonitoredDevice +) + +// Application Startup +func init() { + log.Printf("embedded-bt-rssi-monitor init") + + // Load application configuration from environment variables + /* + envVars := make(map[string]string) + envVars["required"] = os.Getenv("required") + // Validate that all required environment variables are set + for key, value := range envVars { + if value == "" { + log.Fatalf("shell environment variable %s is not set", key) + } + } + */ + + monitoredDevices = make([]MonitoredDevice, 0) + + for i := 0; true; i++ { + macAddress := os.Getenv(fmt.Sprintf("btmacaddress_%d", i)) + if macAddress == "" { + break + } + + fmt.Println("Watching MAC Address: ", macAddress) + + monitoredDevice := MonitoredDevice{MacAddress: macAddress} + monitoredDevices = append(monitoredDevices, monitoredDevice) + } +} + +func main() { + // Enable BLE interface. + must("enable BLE stack", adapter.Enable()) + + go evaluator() + + // Start scanning. + println("scanning...") + err := adapter.Scan(scanHandler) + must("start scan", err) +} + +func must(action string, err error) { + if err != nil { + panic("failed to " + action + ": " + err.Error()) + } +} + +// Runs against every device returned in a scan result +func scanHandler(adapter *bluetooth.Adapter, device bluetooth.ScanResult) { + // First filter out devices that we don't care about + for i := range monitoredDevices { + if monitoredDevices[i].MacAddress == device.Address.String() { + log.Println(device.LocalName(), device.Address, device.RSSI) + monitoredDevices[i].LastPing = time.Now() + monitoredDevices[i].RssiHistory = append(monitoredDevices[i].RssiHistory, device.RSSI) + if len(monitoredDevices[i].RssiHistory) > rssiHistoryLength { // keep up to rssiHistoryLength, and then begin popping out the first element + monitoredDevices[i].RssiHistory = monitoredDevices[i].RssiHistory[1:] + } + break + } + } +} + +// Reads the MonitoredDevices and takes an action +// meant to run in a goroutine +func evaluator() { + + var screenOff bool + + for { + time.Sleep(time.Second * 20) + + bestSignal := rssiThresholdLower + + for i := range monitoredDevices { + if time.Now().After(monitoredDevices[i].LastPing.Add(pingTimeout)) { + continue // ignore device + } + + averageRssi := getAverage(monitoredDevices[i].RssiHistory) + + if averageRssi > bestSignal { + bestSignal = averageRssi + } + } + + if bestSignal > rssiThresholdUpper { + if screenOff { + screenOff = false + log.Printf("setting screen to: budget") + _, err := http.Get(fmt.Sprintf("%sbudget", terminalDashboardURL)) + if err != nil { + log.Printf("failed to set budget screen: %v", err) + } + } + } else if bestSignal <= rssiThresholdLower { + if !screenOff { + screenOff = true + log.Printf("setting screen to: off") + _, err := http.Get(fmt.Sprintf("%soff", terminalDashboardURL)) + if err != nil { + log.Printf("failed to set off screen: %v", err) + } + } + } + } +} + +func getAverage(nums []int16) int16 { + var sum int16 + for _, num := range nums { + sum += num + } + + return sum / int16(len(nums)) +}