From 51d8d5a3f59ed1d13df28bed5fcc3ce09819f773 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Fri, 20 Jan 2017 17:07:34 +0100
Subject: [PATCH] fix how received PZEM messages are handled

---
 lib/sensor_pzem.c |  5 ++++-
 main.c            | 14 +++-----------
 2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/lib/sensor_pzem.c b/lib/sensor_pzem.c
index 6ea15c9..9ee7661 100644
--- a/lib/sensor_pzem.c
+++ b/lib/sensor_pzem.c
@@ -96,13 +96,16 @@ void sensor_pzem_measurement_request(uint32_t address, enum sensor_pzem_measurem
 
 	usart_enable_tx_interrupt(USART(SENSOR_PZEM_USART)); // enable interrupt to send other bytes
 	usart_send(USART(SENSOR_PZEM_USART),tx_buffer[tx_i++]); // start transmission
+
+	sensor_pzem_measurement_received = false; // reset flag
+	rx_i = 0; // prepare buffer to receive next measurement	
 }
 
 struct sensor_pzem_measurement_t sensor_pzem_measurement_decode(void)
 {
 	struct sensor_pzem_measurement_t measurement; // decoded measurement to return
 	measurement.valid = false; // wait until the end to ensure validity
-	if (!sensor_pzem_measurement_received) { // no measurement received
+	if (rx_i<LENGTH(rx_buffer)) { // buffer is not full, thus no measurement received
 		return measurement;
 	}
 	if ((rx_buffer[0]&0xf0)!=0xa0) { // not a response received
diff --git a/main.c b/main.c
index 981b44c..961097b 100644
--- a/main.c
+++ b/main.c
@@ -358,12 +358,12 @@ void main(void)
 	led_on(); // indicate setup is complete
 
 	// variables for PZEM-004T meter measurements
-	struct sensor_pzem_measurement_t pzem_measurements[2][SENSOR_PZEM_MAX]; // PZEM-004T measurements (2 meters, all measurements)
+	struct sensor_pzem_measurement_t pzem_measurements[3][SENSOR_PZEM_MAX]; // PZEM-004T measurements (2 meters, all measurements)
 	uint8_t pzem_meter = 0; // PZEM-004T meter index (add to prefix)
 	uint8_t pzem_measurement = 0; // PZEM-004T measurement index (matches the type)
 
 	// variables for SDM120 meter measurements
-	float sdm120_measurements[2][SENSOR_SDM120_MEASUREMENT_MAX]; // SDM120 measurements (2 meters, all measurements)
+	float sdm120_measurements[3][SENSOR_SDM120_MEASUREMENT_MAX]; // SDM120 measurements (2 meters, all measurements)
 	uint8_t sdm120_meter = 0; // SDM120 meter index (add to 1 to get ID)
 	uint8_t sdm120_measurement = 0; // SDM120 measurement index
 
@@ -396,6 +396,7 @@ void main(void)
 			}
 		}
 		while (sensor_pzem_measurement_received) { // measurement from electricity meter received
+			sensor_pzem_measurement_received = false; // clear flag
 			struct sensor_pzem_measurement_t measurement = sensor_pzem_measurement_decode(); // decode measurement
 			if (measurement.type>=SENSOR_PZEM_MAX) {
 				fprintf(stderr,"unknown measurement type: %u\n", measurement.type);
@@ -513,15 +514,6 @@ void main(void)
 				}	
 			}
 		}
-		while (button_flag) { // user pressed button
-			action = true; // action has been performed
-			printf("button pressed\n");
-			led_toggle(); // toggle LED
-			for (uint32_t i=0; i<1000000; i++) { // wait a bit to remove noise and double trigger
-				__asm__("nop");
-			}
-			button_flag = false; // reset flag
-		}
 		while (rtc_internal_tick_flag) { // the internal RTC ticked
 			rtc_internal_tick_flag = false; // reset flag
 			gpio_toggle(GPIO(LED_HEARTBEAT_PORT), GPIO(LED_HEARTBEAT_PIN)); // toggle heart beat LED to indicate if main function is stuck (do not toggle onboard the LED on PC13 on the blue pill board since this heavily influences the RTC)