Further.

devices/geiger/gqgmc.go

@@ -106,13 +106,13 @@ const (
 	cmdGetSerial  = "<GETSERIAL>>"
 	cmdGetVersion = "<GETVER>>"
 	cmdGetVoltage = "<GETVOLT>>"
-	cmdGetCpm     = "<GETCPM>>"
-	cmdGetCps     = "<GETCPS>>"
+	cmdGetCPM     = "<GETCPM>>"
+	cmdGetCPS     = "<GETCPS>>"
 	cmdGetCfg     = "<GETCFG>>"
 	cmdEraseCfg   = "<ECFG>>"
 	cmdUpdateCfg  = "<CFGUPDATE>>"
-	cmdTurnOnCps  = "<HEARTBEAT1>>"
-	cmdTurnOffCps = "<HEARTBEAT0>>"
+	cmdTurnOnCPS  = "<HEARTBEAT1>>"
+	cmdTurnOffCPS = "<HEARTBEAT0>>"
 	cmdTurnOffPwr = "<POWEROFF>>"
 )
 
@@ -192,14 +192,13 @@ func (gc *GQGMCCounter) SerialNum() (string, error) {
 
 // GetCPM returns CPM
 func (gc *GQGMCCounter) GetCPM() (uint16, error) {
-	//uint32_t cpmsize = 2;          // 2 bytes of returned data
-	//communicate(get_cpm_cmd, cpm_char, cpmsize);
-	// 1st byte is MSB, but note that upper two bits are reserved bits.
-	// Note that shifting and bitmasking performed in uP register, so
-	// endianess is irrevelant.
-	//cpm_int |= ((uint16_t(cpm_char[0]) << 8) & 0x3f00);
-	//cpm_int |=  (uint16_t(cpm_char[1]) & 0x00ff);
-	return 0, nil
+	buf, err := gc.communicate([]byte(cmdGetCPM), 2)
+	if err != nil {
+		return 0, err
+	}
+	cpm := ((uint16(buf[0]) << 8) & 0x3f00)
+	cpm |= (uint16(buf[1]) & 0x00ff)
+	return cpm, nil
 }
 
 // GetCPS returns CPS
@@ -344,19 +343,22 @@ func (gc *GQGMCCounter) SetTime(time string) {
 }
 
 func (gc *GQGMCCounter) communicate(cmd []byte, length uint32) ([]byte, error) {
-	//clearUSB();
-	//if (cmd.size() > 0) sendCmd(cmd);
-	//if (retbytes > 0) readCmdReturn(retdata, retbytes);
+	gc.Clear()
+	if len(cmd) > 0 {
+		gc.sendCmd(cmd)
+	}
+	if length != 0 {
+		return gc.readCmd(length)
+	}
 	return nil, nil
 }
 
 func (gc *GQGMCCounter) sendCmd(cmd []byte) {
-	// The port write thing
 	gc.port.Write(cmd)
 	return
 }
 
-func (gc *GQGMCCounter) readCmdReturn(length uint32) ([]byte, error) {
+func (gc *GQGMCCounter) readCmd(length uint32) ([]byte, error) {
 	buf := make([]byte, length)
 	n, err := gc.port.Read(buf)
 	if err != nil {