jepler/1009-GPS_Derived_RF_Generator
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Allow setting period in addition to frequency

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Some values can be set by period which can't be set by frequency (and
vice versa).  For instance, 6.25Hz (cannot be set by frequency) is
160000us (can be set by period); 300Hz (can be set by frequency) is
3333.33...us (can't be set by period).
This commit is contained in:
Jeff Epler 2019-03-09 10:48:29 -06:00 committed by Jeff Epler
parent 815d006787
commit 541e313bca
1 changed files with 71 additions and 8 deletions
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79
RFout1MHzV1_06/RFout1MHzV1_06.ino
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@ -19,6 +19,7 @@ boolean GPSOK, passthrough;
int cmdstate; // serial command state machine
int fixstate; //GPS Fix state machine 0=Init, 1=wating for fix,2=fix accuired
uint32_t freq; // Frequency in Hz commanded via serial
uint32_t period; // Period in Hz commanded via serial
#define softwareversion "1.06" //Version of this program, sent to serialport at startup
NMEAGPS gps; // This parses the GPS characters
gps_fix fix; // This holds on to the latest values
@ -79,6 +80,7 @@ void setup()
{
Serial.println ("No startup frequency data was found, using 1MHz");
freq = 1000000;
period = 0;
}
//Program GPS
@ -89,13 +91,20 @@ void setup()
delay(500);//Wait for GPSmodule to complete it's power on.
//Program GPS to output RF
if (setGPS_OutputFreq(freq)) {
if (freq && setGPS_OutputFreq(freq)) {
Serial.print (F("GPS Initialized to output RF at "));
Serial.print (freq);
Serial.println (F("Hz"));
Serial.println ("Initialization is complete.");
Serial.println ("");
GPSOK = true;
} else if (period && setGPS_OutputPeriod(period)) {
Serial.print (F("GPS reprogramed to output RF at "));
Serial.print(period);
Serial.print(F("us, approximately "));
Serial.print(1.e6 / period);
Serial.println (F("Hz"));
GPSOK = true;
}
else
{
@ -119,14 +128,18 @@ void handle_serial() {
}
else if(c == 'S' || c == 's') {
SaveToEPROM ();
Serial.println(F("Frequency was saved"));
Serial.println(F("Time pulse setting was saved"));
}
else if(c == 'H' || c == 'h') {
HelpText ();
}
else if(c == 'F' || c == 'f') {
Serial.print(F("Frequency?"));
cmdstate = 1; freq = 0;
cmdstate = 1; freq = period = 0;
}
else if(c == 'T' || c == 't') {
Serial.print(F("Period?"));
cmdstate = 2; freq = period = 0;
}
else if(cmdstate == 1) {
if(c >= '0' && c <= '9') {
@ -143,7 +156,37 @@ void handle_serial() {
if (setGPS_OutputFreq(freq)) {
Serial.print (F("GPS reprogramed to output RF at "));
Serial.print(freq);
Serial.println (F("Hz"));
Serial.println (F("Hz"));
GPSOK = true;
}
else
{
Serial.println (F("Error! Could not reprogram GPS!"));
GPSOK = false;
}
cmdstate = 0;
}
}
else if(cmdstate == 2) {
if(c >= '0' && c <= '9') {
Serial.write(c);
period = period * 10 + c - '0';
} else if (c == 'S' || c == 's') {
Serial.write(c);
period *= 1000000lu;
} else if (c == 'M' || c == 'm') {
Serial.write(c);
period *= 1000lu;
} else if (c == 'U' || c == 'u') {
period *= 1000lu;
} else if (c == '\n' || c == '\r') {
Serial.println(F(""));
if (setGPS_OutputPeriod(period)) {
Serial.print (F("GPS reprogramed to output RF at "));
Serial.print(period);
Serial.print(F("us, approximately "));
Serial.print(1.e6 / period);
Serial.println (F("Hz"));
GPSOK = true;
}
else
@ -214,6 +257,7 @@ uint8_t setOutputFreq[] = {
};
#define OFFSET_FREQUENCY_LOCKED (18)
#define OFFSET_FLAGS (34)
#define OFFSET_CKSUM (38)
// Note: Normally payload_start is 2 bytes past the start of buf, because the first two bytes
@ -230,6 +274,7 @@ void ubx_compute_checksum(uint8_t *payload_start, uint8_t *payload_end, uint8_t
}
bool setGPS_OutputFreq(uint32_t freq) {
setOutputFreq[OFFSET_FLAGS] = 0xef;
for(int i=0; i<4; i++) {
setOutputFreq[OFFSET_FREQUENCY_LOCKED+i] = freq & 0xff;
freq >>= 8;
@ -241,6 +286,19 @@ bool setGPS_OutputFreq(uint32_t freq) {
return gps_set_sucess;
}
bool setGPS_OutputPeriod(uint32_t period) {
setOutputFreq[OFFSET_FLAGS] = 0xe7;
for(int i=0; i<4; i++) {
setOutputFreq[OFFSET_FREQUENCY_LOCKED+i] = period & 0xff;
period >>= 8;
}
ubx_compute_checksum(setOutputFreq+2, setOutputFreq+38, setOutputFreq+38);
sendUBX(setOutputFreq, sizeof(setOutputFreq) / sizeof(uint8_t));
bool gps_set_sucess = getUBX_ACK(setOutputFreq);
// Serial.println(F("Set output Freq Done"));
return gps_set_sucess;
}
bool setGPS_OutputFreq1Kz()
{
return setGPS_OutputFreq(1*KHz);
@ -362,7 +420,7 @@ bool strapped_for_passthrough() {
}
struct eeprom_data {
uint32_t freq;
uint32_t value;
};
@ -388,7 +446,7 @@ unsigned long GetEEPROM_CRC(void) {
void SaveToEPROM ()
{
unsigned long CRCFromEEPROM;
eeprom_data e = {freq};
eeprom_data e = {period ? period | 0x80000000lu : freq};
EEPROM.put(0, e); //Save the Freqency to EEPROM at address0
CRCFromEEPROM=GetEEPROM_CRC (); //Calculate CRC on the saved data
EEPROM.put(sizeof(eeprom_data), CRCFromEEPROM); //Save the CRC after the data
@ -400,10 +458,14 @@ bool LoadFromEPROM (void)
unsigned long CRCFromEEPROM,CalculatedCRC;
eeprom_data e;
EEPROM.get(0, &e); //Load the Frequency from EEPROM address 0
EEPROM.get(0, e); //Load the Frequency from EEPROM address 0
EEPROM.get(sizeof(eeprom_data), CRCFromEEPROM); //Load the CRC value that is stored in EEPROM
CalculatedCRC=GetEEPROM_CRC(); //Calculate the CRC of the Frequency
freq = e.freq;
if(e.value & 0x80000000lu) {
period = e.value & 0x7fffffff; freq = 0;
} else {
period = 0; freq = e.value;
}
return (CRCFromEEPROM==CalculatedCRC); //If Stored and Calculated CRC are the same then return true
}
@ -411,6 +473,7 @@ void HelpText () {
Serial.println(F("Type one of the following serial commands to control the GPS Module: "));
Serial.println(F(" : F ... ,(FREQUENCY) sets a new output frequency, value in Hz or use k or M suffix for kHz and MHz"));
Serial.println(F(" : T ... ,(TIME) sets a new output period, value in us or use m or s suffix for milliseconds and seconds"));
Serial.println(F(" : S ,(SAVE) Saves the current frequency to be used as startup frequency"));
Serial.println(F(" : P ,(PASSTHROUGH) Enters passtrough mode, GPS serial data will be passed to and from this Serial port. Reset the module to go back to normal mode"));
Serial.println(F(" : H ,(HELP) prints this information"));