Implement SPI and remove files

4 files changed, 89 insertions, 0 deletions

diff --git a/examples/spiblink/README.md b/examples/spiblink/README.md
new file mode 100644
index 0000000..3b18a8f
--- /dev/null
+++ b/examples/spiblink/README.md
@@ -0,0 +1,18 @@
+This example shows simple SPI communication. It uses two MCUs. One is configured
+as master. Other is configured as slave. Master has button connected to its input
+and slave has output led. Button status is mirrored by slave led.
+
+Connection
+----------
+Both MCUs needs basic power connections and crystal.
+Except of that, they need following other connections.
+
+| Mater pin | Slave pin | Other connections | Description          |
+|-----------|-----------|-------------------|----------------------|
+| PB1       |           | Led               | Indication of button |
+|           | PB1       | Led               | Receive led          |
+| PB2       | PB2       |                   | SS                   |
+| PB3       | PB3       |                   | MOSI                 |
+| PB4       | PB4       |                   | MISO                 |
+| PB5       | PB5       |                   | SCL                  |
+| PC1       |           | Pull down button  | Input button         |
diff --git a/examples/spiblink/makefile b/examples/spiblink/makefile
new file mode 100644
index 0000000..a831f86
--- /dev/null
+++ b/examples/spiblink/makefile
@@ -0,0 +1,30 @@
+MAKEFLAGS += --no-builtin-rules
+
+MMCU = atmega328p
+F_CPU = 16000000L
+IOE_PREFIX = ../..
+IOE_CFLAGS ?= -Os -ffunction-sections -fdata-sections -fshort-enums -g -Wall
+
+.PHONY: all
+all:  master.hex slave.hex
+	@echo
+	@echo Flash master.hex and slave.hex to two chips and... TODO
+
+.PHONY: all
+clean: ioeclean
+	$(RM) master.o slave.o
+	$(RM) master.elf master.hex
+	$(RM) slave.elf slave.hex
+
+include ../../avr-ioe.mk
+
+master.elf: master.o
+slave.elf: slave.o
+master.elf slave.elf: %.elf: $(IOE_OBJ_SPI)
+	avr-gcc -Os -mmcu=$(MMCU) $^ -o $@
+
+master.hex slave.hex: %.hex: %.elf
+	 avr-objcopy -O ihex -R .eeprom $< $@
+
+master.o slave.o: %.o: %.c
+	avr-gcc $(IOE_CFLAGS) -c -o $@ $<
diff --git a/examples/spiblink/master.c b/examples/spiblink/master.c
new file mode 100644
index 0000000..267d7b2
--- /dev/null
+++ b/examples/spiblink/master.c
@@ -0,0 +1,20 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include "../../spi.h"
+
+int main() {
+    DDRB |= _BV(DDB1) | _BV(DDB2);
+    PORTC |= _BV(PORTC1);
+    spi_init(SPI_MODE_MASTER);
+    SREG |= _BV(7);
+    while (1) {
+        if (PINC & _BV(PINC1)) {
+            PORTB &= ~_BV(PORTB1);
+        } else {
+            PORTB |= _BV(PORTB1);
+        }
+        PORTB &= ~_BV(PORTB2);
+        spi_send(!(PINC & _BV(PINC1)));
+        PORTB |= _BV(PORTB2);
+    }
+}
diff --git a/examples/spiblink/slave.c b/examples/spiblink/slave.c
new file mode 100644
index 0000000..cf14408
--- /dev/null
+++ b/examples/spiblink/slave.c
@@ -0,0 +1,21 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include "../../spi.h"
+
+void receive(uint8_t data);
+
+int main() {
+    DDRB |= _BV(DDB1);
+    spi_receive = receive;
+    spi_init(SPI_MODE_SLAVE);
+    SREG |= _BV(7);
+    while (1) {
+    }
+}
+
+void receive(uint8_t data) {
+    if (data)
+        PORTB |= _BV(PORTB1);
+    else
+        PORTB &= ~_BV(PORTB1);
+}