From cf0df8b102806c4087814b895601321a32026e54 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Wed, 11 Nov 2015 01:39:21 +0100
Subject: [PATCH] make sender more stable by delaying start, reseting address,
 and not waiting before re-requesting

---
 arduino_nano/main.c | 30 ++++++++++++++----------------
 arduino_nano/main.h |  2 +-
 2 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/arduino_nano/main.c b/arduino_nano/main.c
index 19a471c..350a9f0 100644
--- a/arduino_nano/main.c
+++ b/arduino_nano/main.c
@@ -91,6 +91,7 @@ void io_init(void)
 
 int main(void)
 {
+	_delay_ms(1000); // wait a bit until power meter started
 	io_init(); // initialize IOs
 	uint8_t nrf24_payload[1+4*4+1] = {0}; // measurement values to be sent: ID byte + encrypted 4x4 float values (voltage, current, power, energy) + 1 CRC8 Mixim/Dallas/iButton/1Wire of the plain text (to know if the key/IV is correct)
 	
@@ -101,11 +102,8 @@ int main(void)
 	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) */
+	/* PZEM-004 IP address (it won't reply to other requests before it is set) */
 	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)
-	for (uint8_t i=0; i<sizeof(cmd); i++) {
-		usart_putchar_nonblocking(cmd[i],NULL);
-	}
 
 	/* start encryption */
 	aes128_ctx_t ctx; // the context where the round keys are stored
@@ -131,7 +129,6 @@ int main(void)
 	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
 
 	/* PZEM-004 power meter values */
 	float voltage = 0, current = 0, power = 0, energy = 0; // the read values
@@ -153,16 +150,13 @@ int main(void)
 		}
 		if (query_pzem004) {
 			action = true; // an action is performed
-			query_pzem004 = false; // clear flag
-			if (queried_pzem004) { // wait until previous queries finished
-				queried_pzem004 = false;
-				// query all values (voltage, current, power, energy)
-				// start with voltage, the other will be queried after the power meter answered
-				cmd[0] = 0xb0; // query voltage
-				cmd[6] = 0x1a; // update checksum  
-				for (uint8_t i=0; i<sizeof(cmd); i++) {
-					usart_putchar_nonblocking(cmd[i],NULL);
-				}
+			query_pzem004 = false; // clear flag (do not wait until previous is finished)
+			// query all values (voltage, current, power, energy)
+			// start with setting the address, the values will be queried after the power meter answered
+			cmd[0] = 0xb4; // set address
+			cmd[6] = 0x1e; // update checksum  
+			for (uint8_t i=0; i<sizeof(cmd); i++) {
+				usart_putchar_nonblocking(cmd[i],NULL);
 			}
 		}
 		if (usart_incoming>=7) { // wait for an answer to be available
@@ -210,10 +204,14 @@ int main(void)
 						break;
 					case 0xa3: // energy
 						energy = (((uint32_t)answer[1])<<16)+((uint32_t)(answer[2])<<8)+answer[3];
-						queried_pzem004 = true; // all have been queried
 						send_values = true; // this should be the last of the 4 values we requested. now send them
 						break;
 					case 0xa4: // address
+						cmd[0] = 0xb0; // query voltage
+						cmd[6] = 0x1a; // update checksum
+						for (uint8_t i=0; i<sizeof(cmd); i++) {
+							usart_putchar_nonblocking(cmd[i],NULL);
+						}
 						break;
 				}
 			}
diff --git a/arduino_nano/main.h b/arduino_nano/main.h
index 1c832f9..abd2985 100644
--- a/arduino_nano/main.h
+++ b/arduino_nano/main.h
@@ -24,7 +24,7 @@ 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
+	uint8_t request_period; // how many seconds between power meter requests (should be > 2 to have enough time to query all values)
 	uint8_t key[16]; // the AES 128 bits key
 	uint8_t iv[16]; // the initialisation vector for CBC encryption
 };