Write data to EEPROM.

README.md

@@ -17,3 +17,11 @@ sudo ./compile.sh /dev/ttyUSB0
 ```
 
 The port can be found by looking inside `/dev`, the system file `ll /sys/class/tty/ttyUSB*`, or by running `lsusb`.
+
+## Monitoring the serial port
+
+```
+sudo screen /dev/ttyUSB0 9600
+```
+
+To close the program, press `Ctrl + A` and type in `:quit` and hit enter.

at28c256/at28c256.c

@@ -1,19 +1,37 @@
+#include <util/delay.h>
 #include "at28c256.h"
 #include "../ard/pins.h"
 
-unsigned char _addrck, _addr;
+unsigned char _ck, _addr, _oe, _we, _io0, _io1, _io2, _io3, _io4, _io5, _io6, _io7;
 
-void at28c256_init(unsigned char addrck, unsigned char addr) {
+void at28c256_init(unsigned char ck, unsigned char addr, unsigned char oe, unsigned char we, unsigned char io0, unsigned char io1, unsigned char io2, unsigned char io3, unsigned char io4, unsigned char io5, unsigned char io6, unsigned char io7) {
-	pin_mode(addrck, OUTPUT);
+	pin_mode(ck, OUTPUT);
-	digital_write(addrck, LOW); // disable
+	digital_write(ck, LOW); // disable
 	pin_mode(addr, OUTPUT);
 	digital_write(addr, LOW); // disable
+    pin_mode(oe, OUTPUT);
+	digital_write(oe, HIGH); // disable
+    pin_mode(we, OUTPUT);
+	digital_write(we, HIGH); // disable
 	
-    _addrck = addrck;
+    _ck = ck;
 	_addr = addr;
+    _oe = oe;
+    _we = we;
+    _io0 = io0;
+    _io1 = io1;
+    _io2 = io2;
+    _io3 = io3;
+    _io4 = io4;
+    _io5 = io5;
+    _io6 = io6;
+    _io7 = io7;
 }
 
 void at28c256_write(unsigned short addr, unsigned char data) {
+    // just to be safe, disable output
+    digital_write(_oe, HIGH);
+
     // set the address
     unsigned int i;
 
@@ -24,11 +42,22 @@ void at28c256_write(unsigned short addr, unsigned char data) {
             digital_write(_addr, LOW);
         }
 
-        digital_write(_addrck, HIGH);
+        digital_write(_ck, HIGH);
-        digital_write(_addrck, LOW);
+        digital_write(_ck, LOW);
     }
 
     digital_write(_addr, LOW);
 
-    // TODO write data
+    // write data
+    digital_write(_io0, data & 1);
+    digital_write(_io1, data & 1<<1);
+    digital_write(_io2, data & 1<<2);
+    digital_write(_io3, data & 1<<3);
+    digital_write(_io4, data & 1<<4);
+    digital_write(_io5, data & 1<<5);
+    digital_write(_io6, data & 1<<6);
+    digital_write(_io7, data & 1<<7);
+    digital_write(_we, data);
+    _delay_us(1); // min 100ns
+    digital_write(_we, HIGH);
 }

at28c256/at28c256.h

@@ -1,7 +1,7 @@
 #ifndef AT28C256_H_
 #define AT28C256_H_
 
-void at28c256_init(unsigned char, unsigned char);
+void at28c256_init(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char);
 void at28c256_write(unsigned short, unsigned char);
 //unsigned char at28c256_read(unsigned short); TODO
 

main.c

@@ -18,12 +18,13 @@ int main(){
 void prepare() {
 	pins_init();
 	serial_init(9600);
-	at28c256_init(2, 13);
+	at28c256_init(2, 13, 4, 3, 5, 6, 7, 8, 9, 10, 11, 12);
+
+	at28c256_write(0x0000, 0x7B); // 123
+	at28c256_write(0x0001, 0x2A); // 42
 }
 
 void loop() {
-	at28c256_write(0x0001, 0);
+	serial_write("Test\n\r", 6);
-	_delay_ms(1000);
-	at28c256_write(0x8000, 0);
 	_delay_ms(1000);
 }