orthodox: revert TWI support to minimum to debug

- disabled ssd1306 and hardware locking in build configuration
- increased TWI buffer from 0x10 to 0x20 bytes
- decreased TWI clock from 400000 to 100000
- removed hardcoded TWI multi-byte sending/receiving

An 'i2c' build of this was found to work on a rev1 Orthodox, although
slave-side col9 was understandably not working. When testing-time
permits, features will be gradually re-enabled towards getting the full
matrix supported over TWI.

keyboards/orthodox/i2c.h

@@ -14,10 +14,10 @@
 #define I2C_ACK 1
 #define I2C_NACK 0
 
-#define SLAVE_BUFFER_SIZE 0x10
+#define SLAVE_BUFFER_SIZE 0x20
 
 // i2c SCL clock frequency
-#define SCL_CLOCK  400000L
+#define SCL_CLOCK  100000UL
 
 extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];
 

keyboards/orthodox/matrix.c

@@ -181,11 +181,11 @@ int i2c_transaction(void) {
         *((uint8_t*)&matrix[slaveOffset]+i) = i2c_master_read(I2C_NACK);
 	*/
 
-	i2c_master_read(I2C_ACK);
+	// i2c_master_read(I2C_ACK);
 	matrix[slaveOffset+0] = i2c_master_read(I2C_ACK);
-	i2c_master_read(I2C_ACK);
+	// i2c_master_read(I2C_ACK);
 	matrix[slaveOffset+1] = i2c_master_read(I2C_ACK);
-	i2c_master_read(I2C_ACK);
+	// i2c_master_read(I2C_ACK);
 	matrix[slaveOffset+2] = i2c_master_read(I2C_NACK);
 
         i2c_master_stop();
@@ -255,12 +255,17 @@ void matrix_slave_scan(void) {
     // SLAVE_BUFFER_SIZE is from i2c.h
     // (MATRIX_ROWS/2*sizeof(matrix_row_t))
     // memcpy((void*)i2c_slave_buffer, (const void*)&matrix[offset], (ROWS_PER_HAND*sizeof(matrix_row_t)));
-    i2c_slave_buffer[0] = (uint8_t)matrix[offset+0];
+    i2c_slave_buffer[0] = (uint8_t)(matrix[offset+0]);
+    i2c_slave_buffer[1] = (uint8_t)(matrix[offset+1]);
+    i2c_slave_buffer[2] = (uint8_t)(matrix[offset+2]);
+    // note: looks like a possible operator-precedence bug here, in last version?
+    /*
     i2c_slave_buffer[1] = (uint8_t)matrix[offset+0];
     i2c_slave_buffer[2] = (uint8_t)(matrix[offset+1]>>8);
     i2c_slave_buffer[3] = (uint8_t)(matrix[offset+1]>>8);
     i2c_slave_buffer[4] = (uint8_t)(matrix[offset+2]>>8);
     i2c_slave_buffer[5] = (uint8_t)matrix[offset+2];
+    */
 #else // USE_SERIAL
     for (int i = 0; i < ROWS_PER_HAND; ++i) {
         serial_slave_buffer[i] = matrix[offset+i];

keyboards/orthodox/rev1/config.h

@@ -62,9 +62,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define DEBOUNCING_DELAY 5
 
 /* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
-#define LOCKING_SUPPORT_ENABLE
+// #define LOCKING_SUPPORT_ENABLE
 /* Locking resynchronize hack */
-#define LOCKING_RESYNC_ENABLE
+// #define LOCKING_RESYNC_ENABLE
 
 /* key combination for command */
 #define IS_COMMAND() ( \

keyboards/orthodox/rules.mk

@@ -1,8 +1,7 @@
 SRC += matrix.c \
 	   i2c.c \
 	   split_util.c \
-	   serial.c \
-	   ssd1306.c
+	   serial.c
 
 # MCU name
 #MCU = at90usb1287