From db04109912db9fe4a15d20c36e4f3ab2b97f2534 Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Mon, 18 Feb 2019 19:27:34 +0000
Subject: [PATCH] - increased I2C bus speed - added message Fifo

git-svn-id: http://moon:8086/svn/projects/HendiControl@12 fda53097-d464-4ada-af97-ba876c37ca34
---
 Control/firmware/uart_echo/main.c | 117 ++++++++++++++++++++++++++----
 1 file changed, 102 insertions(+), 15 deletions(-)

diff --git a/Control/firmware/uart_echo/main.c b/Control/firmware/uart_echo/main.c
index ffec580..1592a27 100755
--- a/Control/firmware/uart_echo/main.c
+++ b/Control/firmware/uart_echo/main.c
@@ -6,6 +6,8 @@
  */ 
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <avr/io.h>
 #include <avr/interrupt.h>
 #define ARDUINO_NANO
@@ -35,6 +37,89 @@ enum MessageCode
 	Error = 0xFF
 };
 
+typedef struct _sMsg_t
+{
+	uint8_t code;
+	uint8_t data;
+} Msg_t;
+
+typedef struct _sFifo
+{
+	void **ppData;
+	size_t capacity;
+	size_t itemSize;
+	size_t fill;
+	size_t wi;		
+	size_t ri;
+	const char *pName;
+} Fifo;
+
+static Fifo messageFifo;
+
+void Fifo_init(Fifo *pObj, size_t capacity, size_t itemSize, const char *pName)
+{
+	pObj->wi = 0;
+	pObj->ri = 0;
+	pObj->fill = 0;
+	pObj->capacity = capacity;
+	pObj->itemSize = itemSize;
+	pObj->ppData = (void**)malloc(capacity);
+	
+	for (int i=0; i < capacity; i++)
+	{
+		pObj->ppData[i] = (void*)malloc(itemSize);
+	}
+	pObj->pName = pName;
+}
+
+void Fifo_free(Fifo *pObj)
+{
+	for (int i=0; i < pObj->capacity; i++)
+	{
+		free(pObj->ppData[i]);
+	}
+	free (pObj->ppData);
+	pObj->itemSize = 0;
+	pObj->capacity = 0;
+}
+
+void Fifo_push(Fifo *pObj, void *pItem)
+{
+	if (pObj->fill >= pObj->capacity)
+	{
+		printf("%s: Fifo is full\n", pObj->pName);
+		return;
+	}
+	memcpy(pObj->ppData[pObj->wi], pItem, pObj->itemSize);
+	pObj->wi++;
+	pObj->fill++;
+	if (pObj->wi == pObj->capacity)
+	{
+		pObj->wi = 0;
+	}
+}
+
+int Fifo_pop(Fifo *pObj, void *pItem)
+{
+	if (!pObj->fill)
+	{
+		return 0;
+	}
+	memcpy(pItem, pObj->ppData[pObj->ri], pObj->itemSize);
+	pObj->ri++;
+	pObj->fill--;
+	if (pObj->ri == pObj->capacity)
+	{
+		pObj->ri = 0;
+	}
+	return 1;
+}
+
+int Fifo_isEmpty(Fifo *pObj)
+{
+	return pObj->fill == 0;
+}
+
 ISR(ADC_vect)
 {
 	int16_t value_low = (int16_t)ADCL;
@@ -44,8 +129,8 @@ ISR(ADC_vect)
 	
 	if (((adc_value[adc_ch] - value) < -1) || ((adc_value[adc_ch] - value) > 1))
 	{
-		msgCode = AdcComplete;
-		msgData = adc_ch;
+		Msg_t msg = {AdcComplete, adc_ch};
+		Fifo_push(&messageFifo, &msg);
 	}
 	
 	adc_value[adc_ch] = value;
@@ -68,15 +153,17 @@ ISR(USART_RX_vect)
 	} 
 	else if (rx_data >= '0' &&  rx_data <= '9')
 	{
-		msgCode = Command;
-		msgData = rx_data;
+		Msg_t msg = {Command, rx_data};
+		Fifo_push(&messageFifo, &msg);
 	}
 	count++;
 }
 
 ISR (TIMER1_OVF_vect)    // Timer1 ISR
 {
-	msgCode = Timer;
+	Msg_t msg = {Timer, ledState};
+	Fifo_push(&messageFifo, &msg);
+
 	TCNT1 = TIMER_RELOAD;
 	ledState++;
 	if (ledState == 4)
@@ -126,7 +213,7 @@ enum I2C
 void i2c_init()
 {
 	TWBR = 0xFF;
-	TWSR = 0x03;
+	TWSR = 0x00;
 }
 
 void i2c_send(uint8_t addr, uint8_t rw, uint8_t *data, size_t size)
@@ -259,6 +346,7 @@ FILE uart_file = FDEV_SETUP_STREAM(uart_putchar, NULL, _FDEV_SETUP_WRITE);
 
 int main(void)
 {
+	Fifo_init(&messageFifo, 64, sizeof(Msg_t), "Fifo");
 	
     /* Replace with your application code */
 	uart_init();
@@ -276,25 +364,24 @@ int main(void)
 	adc_start_conversion(adc_ch);
 	while (1) 
     {
-	
-		if (msgCode)
+		Msg_t msg;
+		if (!Fifo_isEmpty(&messageFifo))
 		{
 			cli();
-			uint8_t _msgCode = msgCode;
-			uint8_t _msgData = msgData;
+			Fifo_pop(&messageFifo, &msg);
 			sei();
 			
-			switch(_msgCode)
+			switch(msg.code)
 			{
 				case Command:
-				printf("Command : %c\n", _msgData);
-				uint8_t write_dac[] = {0x00+(_msgData-'0'), 0x00};					// 6.2 Write Volatile Memory (C2:C0 = ‘010’)
+				printf("Command : %c\n", msg.data);
+				uint8_t write_dac[] = {0x00+(msg.data-'0'), 0x00};					// 6.2 Write Volatile Memory (C2:C0 = ‘010’)
 				i2c_send(0x60, I2C_WRITE, write_dac, sizeof(write_dac));
 				break;
 			
 				case AdcComplete:
 				{
-					size_t ch = _msgData;
+					size_t ch = msg.data;
 					if (ch == 6)
 					{
 						printf("ADC=%d\n", adc_value[ch]);
@@ -303,7 +390,7 @@ int main(void)
 				break;
 
 				case Timer:
-				switch(ledState)
+				switch(msg.data)
 				{
 					case 0:
 					DDRB = (DDRB & 0xFC) | 0x00;