create a macos launchd file, use channels to wait for BLE con

This commit is contained in:
Wouter Groeneveld 2023-02-01 21:20:35 +01:00
parent 5695d442c6
commit 0badf20ff2
3 changed files with 78 additions and 23 deletions

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@ -14,3 +14,7 @@ If you're on macOS, the Python pybluez Bluetooth drivers don't work (well) on th
The script checks a folder for files (intended to be set up as a cron job), if there are any, sends them to the printer (if detected), **and deletes them**.
See `main.go`, you'll probably want to edit some variables. I hacked everything together in a day for our specific case.
## Launchd service
To install as a `launchd` service (mac's "cron"), copy the binary to `/usr/local/bin` and the file `com.brainbaking.PhomemoPrinter.plist` to `~/Library/LaunchAgents`. Then, in a terminal, type `launchctl load com.brainbaking.PhomemoPrinter.plist`.

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@ -0,0 +1,28 @@
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.brainbaking.phomemoprinter</string>
<key>ProgramArguments</key>
<array>
<string>/usr/local/bin/phomemoprinter</string>
</array>
<key>Nice</key>
<integer>1</integer>
<key>StartInterval</key>
<integer>60</integer>
<key>RunAtLoad</key>
<true/>
<key>StandardErrorPath</key>
<string>/tmp/PhomemoPrinter.err</string>
<key>StandardOutPath</key>
<string>/tmp/PhomemoPrinter.out</string>
</dict>
</plist>

55
main.go
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@ -6,6 +6,7 @@ import (
"os"
"os/exec"
"strconv"
"strings"
"time"
"tinygo.org/x/bluetooth"
)
@ -18,29 +19,40 @@ func main() {
inDir := home + phomemoFolder
files, err := os.ReadDir(inDir)
must(phomemoFolder, err)
must(phomemoFolder + " does not exist", err)
if len(files) == 0 {
log.Printf("No files to print found in %s. Quitting.\n", inDir)
log.Printf("No files to print found in %s, nothing to do. Quitting.\n", inDir)
os.Exit(0)
}
// Enable BLE interface.
must("enable BLE stack", adapter.Enable())
must("Enable Bluetooth stack", adapter.Enable())
// Start scanning. Use this to figure out your device's UUID. Phomemo uses a non-random one.
println("scanning...")
var phomemoAddress bluetooth.ScanResult
log.Println("Scanning for Bluetooth devices...")
ch := make(chan bluetooth.ScanResult, 1)
timeout := make(chan bool, 1)
go func() {
time.Sleep(10 * time.Second)
timeout <- true
}()
go func() {
err = adapter.Scan(func(adapter *bluetooth.Adapter, device bluetooth.ScanResult) {
if device.LocalName() == "Mr.in_M02" {
phomemoAddress = device
println("found device: ", device.Address.String(), device.RSSI, device.LocalName())
ch <- device
adapter.StopScan()
}
})
must("start scan", err)
}()
select {
case device := <- ch:
log.Println("Found device: ", device.Address.String(), device.RSSI, device.LocalName())
tryToPrint(device, inDir, files)
case <- timeout:
log.Fatal("Timeout trying to locate Phomemo M02, is it on? Quitting.")
}
tryToPrint(phomemoAddress, inDir, files)
}
func tryToPrint(phomemoAddress bluetooth.ScanResult, dir string, files []os.DirEntry) {
@ -66,31 +78,42 @@ func tryToPrint(phomemoAddress bluetooth.ScanResult, dir string, files []os.DirE
chars, err := srvc.DiscoverCharacteristics(nil)
must("failed to discover characteristics of service", err)
dumpFilter("phomemo-filter.py")
pyfilterloc := dir + "/" + "phomemo-filter.py"
dumpFilter(pyfilterloc)
defer func() {
os.RemoveAll("phomemo-filter.py")
os.RemoveAll(pyfilterloc)
}()
// 3 characteristics to discover 0000ff01, 0000ff02, and 0000ff03
for _, file := range files {
filePath := dir + "/" + file.Name()
writeData(filePath, chars[1]) // 0000ff02-...
if isPossibleToPrint(filePath) {
writeData(pyfilterloc, filePath, chars[1]) // 0000ff02-...
readResult(chars[0]) // 0000ff01-...
os.RemoveAll(filePath)
}
}
log.Println("-- DONE")
}
func isPossibleToPrint(filename string) bool {
return strings.HasSuffix(filename, ".jpg") ||
strings.HasSuffix(filename, ".JPG") ||
strings.HasSuffix(filename, ".png") ||
strings.HasSuffix(filename, ".PNG")
}
func dumpFilter(filename string) {
err := os.WriteFile(filename, phomemofilter.Pyfilter, 0666)
must("unable to dump python filter for use", err)
}
func writeData(path string, char bluetooth.DeviceCharacteristic) {
func writeData(pyfilterloc string, path string, char bluetooth.DeviceCharacteristic) {
// first, it needs to be prepared for the printer
pathpho := path + ".pho"
argstr := []string{"-c", "python phomemo-filter.py " + path + " > " + pathpho}
argstr := []string{"-c", "/usr/local/bin/python " + pyfilterloc + " " + path + " > " + pathpho}
log.Println("args", argstr)
_, err := exec.Command("/bin/zsh", argstr...).Output()
must("something went wrong while filtering phomemo data py", err)