From f67475e8e423844733bb925cc34871f5aee28627 Mon Sep 17 00:00:00 2001
From: Julian Daube <julian.daube@breadboarder.de>
Date: Sun, 10 Feb 2019 23:03:00 +0100
Subject: [PATCH] small changes

---
 firmware/slider/adc.c  |  12 +---
 firmware/slider/adc.h  |   4 +-
 firmware/slider/main.c | 126 ++++++++++++++++++++++++++++-------------
 firmware/slider/main.h |   1 -
 4 files changed, 91 insertions(+), 52 deletions(-)

diff --git a/firmware/slider/adc.c b/firmware/slider/adc.c
index 0f108dc..1e978fe 100644
--- a/firmware/slider/adc.c
+++ b/firmware/slider/adc.c
@@ -20,13 +20,6 @@ static inline void adc_next() {
 
 		if (!adc.current_channel) {
 			adc.current_sample = adc.buffer.ptr-1;
-
-			// update app state (remap channels)
-			app.state.state.slider  = adc.buffer.ptr[4];
-			app.state.state.poti[0] = adc.buffer.ptr[3];
-			app.state.state.poti[1] = adc.buffer.ptr[2];
-			app.state.state.poti[2] = adc.buffer.ptr[0];
-			app.state.state.poti[3] = adc.buffer.ptr[1];
 		}
 	} while(!(adc.channel_mask & (1<<adc.current_channel)));
 
@@ -55,7 +48,7 @@ void adc_init(adc_buffer_t buffer, uint8_t mask) {
 	}
 
 	ADMUX  = 0;
-	ADCSRA = (1<<ADATE) | (1<<ADEN) ; // enable adc, maximum prescaler value
+	ADCSRA = (1<<ADATE) | (1<<ADEN) | 5 ; // enable adc, maximum prescaler value
 }
 
 void adc_start() {
@@ -66,8 +59,9 @@ void adc_stop( ){
 	ADCSRA &= ~(1<<ADIE);
 }
 
+#include "led.h"
 ISR(ADC_vect) {
-	*adc.current_sample = ADC;
+	**adc.current_sample = ADC;
 	adc_next();
 }
 
diff --git a/firmware/slider/adc.h b/firmware/slider/adc.h
index 2eab70d..cc9cb1a 100644
--- a/firmware/slider/adc.h
+++ b/firmware/slider/adc.h
@@ -13,7 +13,7 @@
 typedef uint16_t adc_sample_t;
 
 typedef struct {
-	adc_sample_t * ptr;
+	adc_sample_t ** ptr;
 	uint8_t size;
 } adc_buffer_t;
 
@@ -21,7 +21,7 @@ typedef struct adc {
 	adc_buffer_t buffer;
 
 	uint8_t current_channel;
-	adc_sample_t * current_sample;
+	adc_sample_t ** current_sample;
 	uint8_t channel_mask;
 } adc_t;
 
diff --git a/firmware/slider/main.c b/firmware/slider/main.c
index ef07a18..8f51148 100644
--- a/firmware/slider/main.c
+++ b/firmware/slider/main.c
@@ -13,35 +13,71 @@
 #include <interface.h>
 
 typedef struct {
+	byte_t * buffer_start, * buffer_end;
+	
+	volatile byte_t * read;
+	volatile byte_t * write;
+	volatile byte_t count; 
+	
 	iface_t iface;
 } comm_t;
 
-comm_t  comm;
+comm_t comm;
+
 void comm_write(iface_t * iface, byte_t byte) {
-	// disable interrupt (temporarily)
-	uint8_t temp = USICR;
-	USICR &= ~(1<<USIOIE);
-
-	// write data register
-	USIDR = byte;
-
-	// wait for buffer overflow
-	while(!(USICR&(1<<USIOIE))) {}
-
-	// restore control register
-	USICR = temp;	
+	if ((comm.write == comm.read) && comm.count) {
+		// write overflow
+		return;
+	}
+	
+	*comm.write = byte;
+	++comm.count;
+	
+	// advance write pointer
+	if ((++comm.write) >= comm.buffer_end) {
+		comm.write = comm.buffer_start;
+	}
 }
 
-void comm_init() {
+inline byte_t comm_read() {
+	if (!comm.count)
+		return 0x00;
+		
+	byte_t result = *comm.read;
+	
+	--comm.count;
+	if ((++comm.read) >= comm.buffer_end) {
+		comm.read = comm.buffer_start;
+	}
+	
+	return result;
+}
+
+byte_t comm_buffer[10];
+
+void comm_init() 
+{
+	comm.buffer_start = comm_buffer;
+	comm.buffer_end   = comm_buffer + sizeof(comm_buffer);
+	
+	// reset buffer
+	comm.write = comm.buffer_start;
+	comm.read  = comm.buffer_start;
+	comm.count = 0;
+	
 	// TODO: setup pins
+	DDRA |= (1<<PA5); // setup MOSI as output
+	
 	// TODO: setup USART in synchronous mode
 	USICR = (1<<USIWM0)|(1<<USICS1);
 
 	// init interface
-	comm.iface.write = comm_write;
+	comm.iface.write   = comm_write;
+	comm.iface.on_read = 0;
 }
 
-void comm_start() {
+void comm_start() 
+{
 	// don't start without interrupt handler
 	if (!comm.iface.on_read)
 		return;
@@ -50,19 +86,18 @@ void comm_start() {
 	USICR |= (1<<USIOIE);
 }
 
-ISR(USI_OVF_vect) {
-	// call interrupt handler
-	comm.iface.on_read(&comm.iface, USIBR, comm.iface.callback_data);
-}
-
-void on_read(iface_t * sender, byte_t b) {
-	if (!IS_EOM(b)) {
-		sender->write(sender, b);
-		return;
-	}
-
-	// strip EOM message
-	sender->write(sender, b&0x7F);
+ISR(USI_OVF_vect) 
+{
+	cli();
+	// write buffer out if there is data to be written
+	//if (!comm.count) {
+		// call interrupt handler
+		//comm.iface.on_read(&comm.iface, USIDR, comm.iface.callback_data);
+	//}
+	
+	USIDR = 0x02;
+	sei();
+	//USIDR = comm_read();
 }
 
 #include "main.h"
@@ -70,8 +105,18 @@ void on_read(iface_t * sender, byte_t b) {
 // the public instance of the app buffer
 struct app app = {};
 
+adc_sample_t * channel_map[] = {
+	// update app state (remap channels)
+	&app.state.state.poti[2],
+	&app.state.state.poti[3],
+	&app.state.state.poti[1],
+	&app.state.state.poti[0],
+	&app.state.state.slider
+};
+
 // initalizes the application modules
-void init() {
+void init() 
+{
 	// init button module (making the button light up on press)
 	// module also updates app.buffer.button for us
 	button_init();
@@ -80,8 +125,8 @@ void init() {
 	// will sample 0x8F (CHANNEL 8 and 0-3) 
 	// this module also updates app.buffer.poti and slider for us
 	adc_init((adc_buffer_t){
-		.ptr  = app.adc_buffer,
-		.size = 5,
+		.ptr  = channel_map,
+		.size = sizeof(channel_map),
 	}, 0x8F);
 
 	// init communication module
@@ -98,21 +143,22 @@ void init() {
 	sei();
 }
 
+#include <util/delay.h>
 
 // little debug helper function
 // FIXME: remove when not needed
-void delay(uint16_t d) {
-	while(d--) {
-		__asm("nop");
+void delay(uint16_t d) 
+{
+	while(d--) 
+	{
+		_delay_ms(1);
 	}
 }
 
-int main() {
+int main() 
+{
 	init();
-
-	// start relevant periphials
-	adc_start();
-
+	
 	while(1) {
 		// nothing to do here, the application is interrupt-driven
 	}
diff --git a/firmware/slider/main.h b/firmware/slider/main.h
index 143a2a5..3e8c14a 100644
--- a/firmware/slider/main.h
+++ b/firmware/slider/main.h
@@ -8,7 +8,6 @@
 
 struct app {
 	slave_t state;
-	adc_sample_t adc_buffer[5];
 };
 
 extern struct app app;