Igor Martinovski
N64 to USB HID interface
Diff: main.cpp
- Revision:
- 0:547c5459faa6
- Child:
- 1:38815edb0ecb
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sun Sep 25 03:44:08 2011 +0000
@@ -0,0 +1,237 @@
+
+/*
+N64 Controller Interface for the mbed.
+
+by Igor Martinovski
+March, 2011.
+
+Function Mapping (from www.mixdown.ca/n64dev/)
+
+Bit Function
+0 A
+1 B
+2 Z
+3 Start
+4 Directional Up
+5 Directional Down
+6 Directional Left
+7 Directional Right
+
+8 unknown (always 0)
+9 unknown (always 0)
+10 L
+11 R
+12 C Up
+13 C Down
+14 C Left
+15 C Right
+
+16-23 X value (signed)
+
+23-32 Y value (signed)
+
+Pinout:
+Looking at the controller plug, flat side down.
+Pin 1 (Left) Ground
+Pin 2 (Center) Data**
+Pin 3 (Right) +3.3V*
+
+(*)Note: The controller is supplied by 3.6V on the N64, but it seems to work fine on
+the 3.3V provided by the mbed.
+
+(**)Warning: The N64 controller must be connected to an open drain pin with a
+pull-up resistor. The line must never be driven high by the mbed! If you are not
+sure how to connect the controller safely, you may damage the mbed and/or
+controller. You have been warned.
+*/
+
+#include "mbed.h"
+#include "stdint.h"
+#include "usbhid.h"
+
+
+USBJoystick joystick;
+
+
+/*
+N64 Controller Interface for the mbed.
+
+by Igor Martinovski
+March, 2011.
+
+Function Mapping (from www.mixdown.ca/n64dev/)
+
+Bit Function
+0 A
+1 B
+2 Z
+3 Start
+4 Directional Up
+5 Directional Down
+6 Directional Left
+7 Directional Right
+
+8 unknown (always 0)
+9 unknown (always 0)
+10 L
+11 R
+12 C Up
+13 C Down
+14 C Left
+15 C Right
+
+16-23 X value (signed)
+
+23-32 Y value (signed)
+
+Pinout:
+Looking at the controller plug, flat side down.
+Pin 1 (Left) Ground
+Pin 2 (Center) Data**
+Pin 3 (Right) +3.3V*
+
+(*)Note: The controller is supplied by 3.6V on the N64, but it seems to work fine on
+the 3.3V provided by the mbed.
+
+(**)Warning: The N64 controller must be connected to an open drain pin with a
+pull-up resistor. The line must never be driven high by the mbed! If you are not
+sure how to connect the controller safely, you may damage the mbed and/or
+controller. You have been warned.
+*/
+
+#include "mbed.h"
+#include "stdint.h"
+
+// Controller Commands
+
+#define GET_STATUS 0x00
+#define REQUEST_CONTROLS 0x01
+#define READ_MEMPACK 0x02
+#define WRITE_MEMPACK 0x03
+#define READ_EEPROM 0x04
+#define WRITE_EEPROM 0x05
+#define RESET_CONTROLLER 0xff
+
+#define T1 24 // Corresponds to 1 us
+#define T2 72 // Corresponds to 3 us
+
+DigitalInOut inout(p14); // Connect controller here
+// using 220 ohm pull-up
+Serial pc(USBTX, USBRX);
+
+uint8_t x, y;
+union controls { /* A definition and a declaration */
+ uint8_t array[4];
+ uint32_t result_32;
+} controls;
+
+// Temp array for controller data
+
+/* void delay(unsigned int n) is used as a short delay to
+ time the bit patterns. 1 n is roughly 0.042us on 96MHz CCLK
+ */
+void delay(unsigned int n) {
+ unsigned int i;
+ for (i=0; i<n; i++)
+ ;
+}
+
+/* int receive(char *data_array, unsigned char n) is used to
+ receive a bit stream of bits into an array of n bytes coming
+ from the controller. This must be called immediately after
+ sending any kind of request to the controller
+ */
+
+int receive(uint8_t *data_array, unsigned char n) {
+ unsigned char sample, previous_sample;
+ unsigned char bit, byte;
+ int i;
+
+
+ //inout.input(); // Not sure about this..
+
+ sample = inout.read();
+ for (i=0;i < n ;i++) {
+ byte = 0;
+ bit = 0;
+ while (bit<8) {
+ previous_sample = sample;
+ sample = inout.read();
+ if ((previous_sample ^ sample) & previous_sample) {
+
+ delay(60);
+ sample=inout.read();
+ if (sample)
+ byte = byte | (1<<bit);
+ bit++;
+ }
+
+ data_array[i]= byte;
+ }
+
+ }
+ /* The for loop here is used to reverse the bits for the x and y values retured
+ by the controller. I am not entirely sure of the format. I'm missing a bit
+ somewhere.. Values don't range from -127..128. */
+ x=y=0;
+ for (i=0;i<=7;i++) {
+ if (controls.array[2] & (1 << i))
+ x=x | (1 << (7-i));
+ if (controls.array[3] & (1 << i))
+ y=y | (1 << (7-i));
+ }
+ data_array[2]=x;
+ data_array[3]=y;
+ return n;
+}
+/* void send_byte(unsigned char byte) is used to send a single
+ byte to the controller.
+ */
+void send_byte(unsigned char byte) {
+ char i;
+ //inout.output(); // Not sure about this.
+ inout.write(1); // Makes sure line is left high
+
+ wait_us(500);
+ for (i=0; i<8; i++) {
+ if (byte & 128>>i) {
+ inout.write(0);
+ delay(T1);
+ inout.write(1);
+ delay(T2);
+ } else {
+ inout.write(0);
+ delay(T2);
+ inout.write(1);
+ delay(T1);
+ }
+ }
+ /* Send Stop Bit */
+ inout.write(0);
+ delay(T1);
+ inout.write(1);
+ delay(T1);
+
+}
+
+int main() {
+ inout.mode(OpenDrain); // Must use open-drain for N64 Controller!
+
+ uint32_t i, previous_result=0; // Used for the bit-shifting for x and y values
+ send_byte(RESET_CONTROLLER);
+ wait_ms(10);
+ while (1) {
+ wait_ms(10);
+ previous_result=controls.result_32;
+ send_byte(1); // Send the request byte
+ receive(controls.array, 4); // Start receiving bit stream
+
+ if (controls.result_32==previous_result) continue;
+
+
+ pc.printf("%3d %3d %d %d\n ", controls.array[0], controls.array[1], (int8_t)controls.array[2], (int8_t)controls.array[3]);
+ //pc.printf("%d\n",controls.result_32);
+//joystick.joystick(controls.array[0],controls.array[1], controls.array[2], controls.array[3]);
+ }
+
+}
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