diff --git a/apps/ir_uart_demo1/Makefile b/apps/ir_uart_demo1/Makefile
new file mode 100644
index 0000000..3b4cf23
--- /dev/null
+++ b/apps/ir_uart_demo1/Makefile
@@ -0,0 +1,89 @@
+# File:   Makefile
+# Author: M. P. Hayes, UCECE
+# Date:   12 Sep 2010
+# Descr:  Makefile for ir_uart_demo1
+
+# Definitions.
+CC = avr-gcc
+CFLAGS = -mmcu=atmega32u2 -Os -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/avr -I../../fonts -I../../drivers -I../../utils
+OBJCOPY = avr-objcopy
+SIZE = avr-size
+DEL = rm
+
+
+# Default target.
+all: ir_uart_demo1.out
+
+
+# Compile: create object files from C source files.
+ir_uart_demo1.o: ir_uart_demo1.c ../../drivers/avr/ir_uart.h ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/navswitch.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h ../../utils/uint8toa.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+prescale.o: ../../drivers/avr/prescale.c ../../drivers/avr/prescale.h ../../drivers/avr/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+system.o: ../../drivers/avr/system.c ../../drivers/avr/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+timer.o: ../../drivers/avr/timer.c ../../drivers/avr/system.h ../../drivers/avr/timer.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+timer0.o: ../../drivers/avr/timer0.c ../../drivers/avr/bits.h ../../drivers/avr/prescale.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+usart1.o: ../../drivers/avr/usart1.c ../../drivers/avr/system.h ../../drivers/avr/usart1.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+display.o: ../../drivers/display.c ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/ledmat.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ledmat.o: ../../drivers/ledmat.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/ledmat.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+navswitch.o: ../../drivers/navswitch.c ../../drivers/avr/delay.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/navswitch.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+font.o: ../../utils/font.c ../../drivers/avr/system.h ../../utils/font.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+task.o: ../../utils/task.c ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../utils/task.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+tinygl.o: ../../utils/tinygl.c ../../drivers/avr/system.h ../../drivers/display.h ../../utils/font.h ../../utils/tinygl.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+uint8toa.o: ../../utils/uint8toa.c ../../drivers/avr/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+
+
+
+# Link: create output file (executable) from object files.
+ir_uart_demo1.out: ir_uart_demo1.o ir_uart.o pio.o prescale.o system.o timer.o timer0.o usart1.o display.o ledmat.o navswitch.o font.o task.o tinygl.o uint8toa.o
+	$(CC) $(CFLAGS) $^ -o $@ -lm
+	$(SIZE) $@
+
+
+# Create hex file for programming from executable file.
+ir_uart_demo1.hex: ir_uart_demo1.out
+	$(OBJCOPY) -O ihex ir_uart_demo1.out ir_uart_demo1.hex
+
+
+# Target: clean project.
+.PHONY: clean
+clean: 
+	-$(DEL) *.o *.out *.hex
+
+
+# Target: program project.
+.PHONY: program
+program: ir_uart_demo1.hex
+	dfu-programmer atmega32u2 erase; dfu-programmer atmega32u2 flash ir_uart_demo1.hex; dfu-programmer atmega32u2 start
+
+
diff --git a/apps/ir_uart_demo1/Makefile.test b/apps/ir_uart_demo1/Makefile.test
new file mode 100644
index 0000000..70f4d4b
--- /dev/null
+++ b/apps/ir_uart_demo1/Makefile.test
@@ -0,0 +1,70 @@
+# File:   Makefile
+# Author: M. P. Hayes, UCECE
+# Date:   11 Sep 2010
+# Descr:  Makefile for ir_uart_demo1
+
+CC = gcc
+CFLAGS = -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/test -I../../drivers -I../../fonts -I../../utils
+
+DEL = rm
+
+
+# Default target.
+all: ir_uart_demo1
+
+
+# Compile: create object files from C source files.
+ir_uart_demo1-test.o: ir_uart_demo1.c ../../drivers/display.h ../../drivers/navswitch.h ../../drivers/test/ir_uart.h ../../drivers/test/system.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h ../../utils/uint8toa.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+display-test.o: ../../drivers/display.c ../../drivers/display.h ../../drivers/ledmat.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ledmat-test.o: ../../drivers/ledmat.c ../../drivers/ledmat.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+navswitch-test.o: ../../drivers/navswitch.c ../../drivers/navswitch.h ../../drivers/test/avrtest.h ../../drivers/test/delay.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ir_uart-test.o: ../../drivers/test/ir_uart.c ../../drivers/test/ir_uart.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+mgetkey-test.o: ../../drivers/test/mgetkey.c ../../drivers/test/mgetkey.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+pio-test.o: ../../drivers/test/pio.c ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+system-test.o: ../../drivers/test/system.c ../../drivers/test/avrtest.h ../../drivers/test/mgetkey.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drivers/test/timer.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+font-test.o: ../../utils/font.c ../../drivers/test/system.h ../../utils/font.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+task-test.o: ../../utils/task.c ../../drivers/test/system.h ../../drivers/test/timer.h ../../utils/task.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+tinygl-test.o: ../../utils/tinygl.c ../../drivers/display.h ../../drivers/test/system.h ../../utils/font.h ../../utils/tinygl.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+uint8toa-test.o: ../../utils/uint8toa.c ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+
+
+
+# Link: create executable file from object files.
+ir_uart_demo1: ir_uart_demo1-test.o display-test.o ledmat-test.o navswitch-test.o ir_uart-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o font-test.o task-test.o tinygl-test.o uint8toa-test.o
+	$(CC) $(CFLAGS) $^ -o $@ -lrt
+
+
+# Clean: delete derived files.
+.PHONY: clean
+clean: 
+	-$(DEL) ir_uart_demo1 ir_uart_demo1-test.o display-test.o ledmat-test.o navswitch-test.o ir_uart-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o font-test.o task-test.o tinygl-test.o uint8toa-test.o
+
+
+
diff --git a/apps/ir_uart_demo1/doc/Makefile b/apps/ir_uart_demo1/doc/Makefile
new file mode 100644
index 0000000..195c459
--- /dev/null
+++ b/apps/ir_uart_demo1/doc/Makefile
@@ -0,0 +1,45 @@
+# File:   Makefile
+# Author: M. P. Hayes, UCECE
+# Date:   11 Sep 2010
+# Descr:  Makefile for ir_uart_test3 docs
+
+# The scripts used to make the graphs require the program dot; this
+# is part of the graphviz package.
+
+DEL = rm
+
+all: file_dependencies.pdf module_dependencies.pdf makefile_dependencies.pdf build_dependencies.pdf callgraph.pdf
+
+file_dependencies.pdf: files.d 
+	../../../etc/graphdeps.py $< --out $@
+
+module_dependencies.pdf: modules.d 
+	../../../etc/graphdeps.py $< --modules --rotate --out $@
+
+makefile_dependencies.pdf: ../Makefile
+	../../../etc/graphdeps.py $< --out $@
+
+build_dependencies.pdf: ../Makefile
+	../../../etc/graphdeps.py $< --out $@ --showops
+
+callgraph.pdf: callgraph.d
+	../../../etc/graphdeps.py --calls --modules $< --out $@ --showops
+
+
+files.d: ../Makefile
+	(cd ..;	../../etc/makemake.py --relpath --files . . ../../drivers ../../drivers/avr ../../utils ../../extra --exclude system.h > doc/files.d)
+
+
+modules.d: ../Makefile
+	(cd ..;	../../etc/makemake.py --relpath --modules . . ../../drivers ../../drivers/avr ../../utils ../../extra --exclude system > doc/modules.d)
+
+
+callgraph.d: ../Makefile
+	(cd ..;	../../etc/makemake.py --cc="avr-gcc" --cflags="-Os -mmcu=atmega32u2" --relpath --calls . . ../../drivers ../../drivers/avr ../../utils ../../extra --exclude system.h > doc/callgraph.d)
+
+
+# Clean: delete derived files.
+.PHONY: clean
+clean: 
+	-$(DEL) *.d *.pdf
+
diff --git a/apps/ir_uart_demo1/doc/README b/apps/ir_uart_demo1/doc/README
new file mode 100644
index 0000000..39a9712
--- /dev/null
+++ b/apps/ir_uart_demo1/doc/README
@@ -0,0 +1,16 @@
+Running make in this directory will generate a number of PDF graphs.
+In the callgraph, the arrows means "calls".  In the dependency graphs,
+the arrows means "requires" (or "depends upon").
+
+callgraph.pdf             This shows the callgraph, i.e., what functions each
+                          function in the program calls.
+module_dependencies.pdf   This shows the dependencies between the modules.
+file_dependencies.pdf     This shows the dependencies between the files.
+makefile_dependencies.pdf This shows the dependencies required by make when
+                          building the program.
+build_dependencies.pdf    This is like makefile_dependencies.pdf but shows
+                          the operations performed to generate the new file.
+
+callgraph.d               This shows the callgraph in text format.
+files.d                   This shows the file dependencies in text format.
+modules.d                 This shows the module dependencies in text format.
diff --git a/apps/ir_uart_demo1/ir_uart_demo1.c b/apps/ir_uart_demo1/ir_uart_demo1.c
new file mode 100644
index 0000000..ad8398f
--- /dev/null
+++ b/apps/ir_uart_demo1/ir_uart_demo1.c
@@ -0,0 +1,131 @@
+/** @file   ir_uart_demo1.c
+    @author M. P. Hayes, UCECE
+    @date   3 October 2013
+    @brief  Test program for IR UART communications showing encoding.
+*/
+
+#include "system.h"
+#include "navswitch.h"
+#include "tinygl.h"
+#include "task.h"
+#include "uint8toa.h"
+#include "ir_uart.h"
+
+#define DISPLAY_TASK_RATE 200
+
+#define IR_UART_TX_TASK_RATE 20
+
+#define IR_UART_RX_TASK_RATE 20
+
+#define NAVSWITCH_TASK_RATE 20
+
+typedef enum {XPOS, YPOS} tx_message_t;
+
+typedef enum {SEND_XPOS, SEND_YPOS} tx_state_t;
+
+
+static tinygl_point_t this_pos;
+static tinygl_point_t other_pos;
+
+
+static void display_task (__unused__ void *data)
+{
+    tinygl_update ();
+}
+
+
+static void ir_uart_tx_task (__unused__ void *data)
+{
+    static uint8_t state = SEND_XPOS;
+
+    /* Alternately, send x position and y position messages.  */
+    switch (state)
+    {
+    case SEND_XPOS:
+        ir_uart_putc ((XPOS << 4) | (this_pos.x & 0x0f));
+        state = SEND_YPOS;
+        break;
+
+    case SEND_YPOS:
+        ir_uart_putc ((YPOS << 4) | (this_pos.y & 0x0f));
+        state = SEND_XPOS;
+        break;
+    }
+}
+
+
+static void ir_uart_rx_task (__unused__ void *data)
+{
+    uint8_t c;
+
+    if (!ir_uart_read_ready_p ())    
+        return;
+
+    tinygl_draw_point (other_pos, 0);
+
+    c = ir_uart_getc ();
+
+    /* Decode the received message.  */
+    switch (c >> 4)
+    {
+    case XPOS:
+        other_pos.x = c & 0x0f;
+        break;
+
+    case YPOS:
+        other_pos.y = c & 0x0f;
+        break;
+    }
+    tinygl_draw_point (other_pos, 1);
+}
+
+
+static void navswitch_task (__unused__ void *data)
+{
+    tinygl_point_t newpos;
+
+    navswitch_update ();
+    
+    newpos = this_pos;
+
+    if (navswitch_push_event_p (NAVSWITCH_NORTH))
+        newpos.y--;
+    if (navswitch_push_event_p (NAVSWITCH_SOUTH))
+        newpos.y++;
+    if (navswitch_push_event_p (NAVSWITCH_EAST))
+        newpos.x++;
+    if (navswitch_push_event_p (NAVSWITCH_WEST))
+        newpos.x--;
+
+    /* Note, there is no checking that have moved off screen.  */
+
+    if (this_pos.x != newpos.x || this_pos.y != newpos.y)
+    {
+        tinygl_draw_point (this_pos, 0);
+        this_pos = newpos;
+        tinygl_draw_point (this_pos, 1);
+    }
+}
+
+
+int main (void)
+{
+    task_t tasks[] =
+    {
+        {.func = display_task, .period = TASK_RATE / DISPLAY_TASK_RATE},
+        {.func = ir_uart_rx_task, .period = TASK_RATE / IR_UART_RX_TASK_RATE},
+        {.func = ir_uart_tx_task, .period = TASK_RATE / IR_UART_TX_TASK_RATE},
+        {.func = navswitch_task, .period = TASK_RATE / NAVSWITCH_TASK_RATE},
+    };    
+
+    system_init ();
+    ir_uart_init ();
+    tinygl_init (DISPLAY_TASK_RATE);
+
+    this_pos = tinygl_point (TINYGL_WIDTH / 2, TINYGL_HEIGHT / 2);
+    tinygl_draw_point (this_pos, 1);
+
+    task_schedule (tasks, 4);
+
+    return 0;
+}