request power meter request periode to 5 seconds and make it as setting

README.md

@@ -92,7 +92,6 @@ TODO
 
 arduino_nano:
 - use encryption for the RF communication (AES-128)
-- user a slower timer value (5s) for querying the PZEM-004 data. currently it's set to 1s but the power meter needs already more time for the 4 requested values
 - enable the watchdog (in case the interrupt handling is putting the device in an unexpected state)
 
 rpi:

arduino_nano/main.c

@@ -38,7 +38,8 @@
 #include "nrf24.h" // nRF24L01 functions
 
 /* variables */
-volatile bool query_pzem004 = false; // flag to query the PZEM-004 power meter
+bool query_pzem004 = false; // flag to query the PZEM-004 power meter
+volatile uint8_t timer_seconds = 0; // how many seconds have passed
 
 /* disable watchdog when booting */
 void wdt_init(void) __attribute__((naked)) __attribute__((section(".init3")));
@@ -63,7 +64,7 @@ void io_init(void)
 	TCCR1B |= (0<<WGM13)|(1<<WGM12); // use timer 1 in CTC mode
 	TCCR1A |= (0<<WGM11)|(0<<WGM10); // use timer 1 in CTC mode
 	TCNT1 = 0; // reset timer 1 counter
-	OCR1A = (F_CPU/256UL)*1.0; // the time to wait before triggering. with a prescale of 256 the max is 1.05s. here I choose 1s.
+	OCR1A = F_CPU/256UL; // the timer to trigger every second with a prescale of 256 (the max is 1.05s)
 	TIMSK1 |= (1<<OCIE1A); // enable interrupt
 	
 	sei(); // enable interrupts
@@ -75,8 +76,7 @@ int main(void)
 	
 	//printf(PSTR("welcome to the spar counter power meter monitor\n"));
 	
-	/* fallback nRF24 node configuration */
-	struct configuration conf = {{1,'h','o','m','e'},{0,'h','o','m','e'},42};
+	struct configuration conf; // node configuration
 	// read configuration data from EEPROM + CRC-8-iButton value
 	uint8_t eeprom_conf[sizeof(struct configuration)+1];
 	uint8_t crc = 0; // CRC8 iButton/1Wire/Dallas/Maxim calculation
@@ -84,12 +84,13 @@ int main(void)
 		eeprom_conf[i] = eeprom_read_byte((const uint8_t*)i); // read data
 		crc = _crc_ibutton_update(crc, eeprom_conf[i]); // calculate CRC
 	}
-	if (crc==0) { // CRC succeeded
-		memcpy(&conf,eeprom_conf,sizeof(struct configuration));
+	if (crc) { // CRC failed
+		return 1; // stop doing anything
 	}
-	nrf24_set_rx_addr(conf.rx_addr);
-	nrf24_set_tx_addr(conf.tx_addr);
-	nrf24_set_rf_channel(conf.channel);
+	memcpy(&conf,eeprom_conf,sizeof(struct configuration)); // get configuration
+	nrf24_set_rx_addr(conf.rx_addr); // set device receiving address
+	nrf24_set_tx_addr(conf.tx_addr); // set transmission destination address
+	nrf24_set_rf_channel(conf.channel); // set transceiver channel
 	
 	/* set the PZEM-004 IP address (it won't reply to other requests before) */
 	uint8_t cmd[7] = {0xB4,0xC0,0xA8,0x01,0x01,0x00,0x1E}; // set the address 192.168.1.1 (keep this address for the other commands)
@@ -98,6 +99,7 @@ int main(void)
 	}
 	
 	/* start timer to periodically query the power meter */
+	timer_seconds = 0; // restart seconds counter
 	TCCR1B |= (1<<CS12)|(0<<CS11)|(0<<CS10); // set prescale to 256 (starting the timer)
 	query_pzem004 = false; // immediately start querying the power meter
 	bool queried_pzem004 = true; // all values have been queried from the power meter
@@ -106,9 +108,14 @@ int main(void)
 	float voltage = 0, current = 0, power = 0, energy = 0; // the read values
 	bool send_values = false; // set to true to send out the values
 	
-	bool action = false; // to know if we performed any king of action during which some other activity could have happend
+	bool action = false; // to know if we performed any king of action during which some other activity could have happened
 	while (true) { // endless loop for micro-controller
 		action = false; // new cycle of actions
+		if (timer_seconds!=0 && timer_seconds==conf.request_period) {
+			action = true; // an action is performed
+			timer_seconds = 0; // restart timer
+			query_pzem004 = true; // remember to query power meter
+		}
 		if (query_pzem004) {
 			action = true; // an action is performed
 			query_pzem004 = false; // clear flag
@@ -235,10 +242,8 @@ int main(void)
 	return 0;
 }
 
-/* timer 1 triggered
- * start querying the power meter
- */
+/* timer 1 triggered */
 ISR(TIMER1_COMPA_vect)
 {
-	query_pzem004 = true; // warm main programm to start querying
+	timer_seconds++; // count seconds
 }

arduino_nano/main.h

@@ -18,29 +18,18 @@
  * they are then transmitted using an nRF2L01+ transceiver
  */
  
-/* peripherals */
-/* LED to indicate scale reading
- * pin: PB5, LED L
- */
-/* not used because PB5 is used for SCK
-#define LED_IO PB5
-#define LED_PORT PORTB
-#define LED_DDR DDRB
-#define LED_PIN PINB
-*/
-
-
 /* spark counter configuration */
 struct configuration {
 	uint8_t rx_addr[5]; // nRF24 receiving address
 	uint8_t tx_addr[5]; // nRF24 transmit address
 	uint8_t channel; // nRF24 channel
+	uint8_t request_period; // how many seconds between power meter requests
 };
 
 /* spark counter default configuration stored in EEPROM
  * it's corresponds to the configuration structure
- * there is an additionnal CRC8 iButton/1Wire/Dallas/Maxim checksum
+ * there is an additional CRC8 iButton/1Wire/Dallas/Maxim checksum
  * the variable order is reversed (avr-gcc behaviour?)
  */
-uint8_t EEMEM eeprom_crc = 0xeb; // CRC8-ibutton checksum
-struct configuration EEMEM eeprom_default_conf = {{1,'h','o','m','e'},{0,'h','o','m','e'},42};
+uint8_t EEMEM eeprom_crc = 0xf6; // CRC8-ibutton checksum
+struct configuration EEMEM eeprom_default_conf = {{1,'h','o','m','e'},{0,'h','o','m','e'},42,5};