commit 585b8875a4ed38d3fc27dab7a2b669511fa63ccf
Author: LongHairedHacker <sebastian@sebastians-site.de>
Date:   Fri Dec 9 01:35:15 2016 +0100

    Interpolating temperature points and displaying them works

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5e56e04
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/bin
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..5107749
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "avr-st7735"]
+	path = avr-st7735
+	url = git@github.com:LongHairedHacker/avr-st7735.git
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..c79537e
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,76 @@
+AVRMCU ?= atmega8
+F_CPU ?= 16000000
+ISPPORT ?= /dev/kaboard
+
+VERSION = 0.1
+
+# ST7735 stuff
+HEADERS = avr-st7735/include/spi.h
+HEADERS += avr-st7735/include/st7735.h avr-st7735/include/st7735initcmds.h
+HEADERS += avr-st7735/include/st7735_gfx.h avr-st7735/include/st7735_font.h
+HEADERS += avr-st7735/images/logo_bw.h avr-st7735/fonts/free_sans.h
+
+SRC = avr-st7735/spi.c avr-st7735/st7735.c
+SRC += avr-st7735/st7735_gfx.c avr-st7735/st7735_font.c
+
+# Local stuff
+SRC += main.c
+TARGET = reflow-firmware
+OBJDIR = bin
+
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+OBJDUMP = avr-objdump
+SIZE = avr-size
+
+SRC_TMP = $(subst ../,,$(SRC))
+OBJ = $(SRC_TMP:%.c=$(OBJDIR)/$(AVRMCU)/%.o)
+
+CFLAGS = -I avr-st7735/include -I avr-st7735/images -I avr-st7735/fonts
+CFLAGS += -Os -Wall -Wstrict-prototypes
+CFLAGS += -ffunction-sections -fdata-sections
+CFLAGS += -fshort-enums -fpack-struct -funsigned-char -funsigned-bitfields
+CFLAGS += -mmcu=$(AVRMCU) -DF_CPU=$(F_CPU)UL -DVERSION=$(VERSION)
+
+LDFLAGS = -mmcu=$(AVRMCU) -Wl,--gc-sections
+
+all: start $(OBJDIR)/$(AVRMCU)/$(TARGET).hex size
+	@echo ":: Done !"
+
+start:
+	@echo "Reflow Firmware $(VERSION)"
+	@echo "=========================="
+	@echo ":: Building for $(AVRMCU)"
+	@echo ":: MCU operating frequency is $(F_CPU)Hz"
+
+images/logo.h : images/logo.png utils/img_convert.py
+	python3 utils/img_convert.py $< $@
+
+images/logo_bw.h : images/logo_bw.png utils/img_convert_mono.py
+	python3 utils/img_convert_mono.py $< $@
+
+$(OBJDIR)/$(AVRMCU)/%.o : %.c $(HEADERS) Makefile
+	@mkdir -p $$(dirname $@)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(OBJDIR)/$(AVRMCU)/$(TARGET).elf : $(OBJ)
+	$(CC) $(LDFLAGS) $+ -o $@
+
+$(OBJDIR)/$(AVRMCU)/$(TARGET).hex : $(OBJDIR)/$(AVRMCU)/$(TARGET).elf
+	$(OBJCOPY) -O ihex $< $@
+
+size : $(OBJDIR)/$(AVRMCU)/$(TARGET).elf
+	@echo
+	@$(SIZE) --mcu=$(AVRMCU) -C $(OBJDIR)/$(AVRMCU)/$(TARGET).elf
+	@echo
+
+clean :
+	@rm -rf $(OBJDIR)
+
+flash : all
+	avrdude -c arduino \
+		-p $(AVRMCU) -P $(ISPPORT) \
+        -U flash:w:$(OBJDIR)/$(AVRMCU)/$(TARGET).hex
+
+test : flash
+	screen $(ISPPORT) 38400
diff --git a/avr-st7735 b/avr-st7735
new file mode 160000
index 0000000..3d03fa4
--- /dev/null
+++ b/avr-st7735
@@ -0,0 +1 @@
+Subproject commit 3d03fa4038aea6ef89e1b17c6da0e9732284d912
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..c6d412b
--- /dev/null
+++ b/main.c
@@ -0,0 +1,79 @@
+#include<avr/io.h>
+#include<util/delay.h>
+
+#include "spi.h"
+#include "st7735.h"
+#include "st7735_gfx.h"
+#include "st7735_font.h"
+
+#include "logo_bw.h"
+
+#include "free_sans.h"
+
+uint8_t profile_point_count = 5;
+uint16_t profile[5][2] = {
+    {0, 22},
+    {90, 150},
+    {180, 180},
+    {210, 210},
+    {270, 180},
+};
+
+uint16_t interpolate_profile(uint16_t t) {
+    if(t > profile[profile_point_count -1][0]) {
+        return profile[profile_point_count -1][1] * 100;
+    }
+
+    uint8_t pos;
+    for(pos = 0; pos < profile_point_count; pos++) {
+        if(profile[pos][0] > t) {
+            break;
+        }
+    }
+
+    int16_t time_diff = profile[pos][0] - profile[pos - 1][0];
+    int16_t tmp_diff = (profile[pos][1] - profile[pos - 1][1]) * 100;
+    int16_t gradient = tmp_diff / time_diff;
+
+    return gradient * (t - profile[pos - 1][0]) + profile[pos - 1][1] * 100;
+}
+
+
+void splash_screen(void) {
+    st7735_fill_rect(0, 0, 160, 128, ST7735_COLOR_BLACK);
+    st7735_draw_mono_bitmap(16, 4, &logo_bw, ST7735_COLOR_WHITE, ST7735_COLOR_BLACK);
+    _delay_ms(2000);
+}
+
+void draw_plot_template(void) {
+    st7735_fill_rect(0, 0, 160, 128, ST7735_COLOR_BLACK);
+
+    for(uint8_t y = 28; y < 128; y += 10) {
+        st7735_draw_fast_hline(0, y, 160, st7735_color(128,128,128));
+    }
+
+    for(uint8_t x = 10; x < 160; x+=10) {
+        st7735_draw_fast_vline(x, 20, 128, st7735_color(128,128,128));
+    }
+
+    for(uint8_t t = 0; t < 160; t++) {
+        uint16_t temp = interpolate_profile(t * 2);
+
+        st7735_draw_pixel(t, 127 - (temp / 250), ST7735_COLOR_CYAN);
+    }
+}
+
+
+int main(void) {
+    spi_init();
+    st7735_init();
+
+    st7735_set_orientation(ST7735_LANDSCAPE);
+
+    splash_screen();
+
+    draw_plot_template();
+
+
+    while(1);
+}