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LoaderTest: Support Arduino Micro configuration
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@kervinck
kervinck committed Jun 3, 2018
1 parent bb397fa commit e6b19d2
Showing 1 changed file with 139 additions and 50 deletions.
189 changes: 139 additions & 50 deletions Utils/LoaderTest/LoaderTest.ino
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@@ -1,8 +1,17 @@

// Concept tester for interfacing with the
// Gigatron TTL microcomputer
// Marcel van Kervinck / Chris Lord
// May 2018

// Select 1 of the platforms
#define ArduinoUno 1
#define ArduinoMicro 0
#define ATtiny85 0

// Select a built-in GT1 image
const byte gt1File[] PROGMEM = {
//#include "Blinky.h" // Blink pixel in middle of screen
#include "Lines.h" // Draw randomized lines (at67)
};

// The object file is embedded (in PROGMEM) in GT1 format. It would be
// GREAT if we can find a way to receive the file over the Arduino's
Expand All @@ -28,31 +37,103 @@
// XXX Keyboard: Is it possible to mimic key hold-down properly???
// XXX Embed a Gigatron Terminal program. Or better: GigaMon

const byte gt1File[] PROGMEM = {
//#include "Blinky.h" // Blink pixel in middle of screen
#include "Lines.h" // Draw randomized lines
};

/*
* Link to Gigatron using its serial game controller port
*/

// Arduino AVR Gigatron Schematic Controller PCB
// Uno Name OUT bit CD4021 74HC595 (U39)
// ------- ------ -------- --------- ---------- ----------------
// Pin 13 PORTB5 None SER_DATA 11 SER INP 14 SER
// Pin 12 PORTB4 7 vSync SER_LATCH 0 PAR/SER None
// Pin 11 PORTB3 6 hSync SER_PULSE 10 CLOCK 11 SRCLK 12 RCLK

// Game controller button mapping. The kit's controller gives inverted signals.
#define buttonRight 1
#define buttonLeft 2
#define buttonDown 4
#define buttonUp 8
#define buttonStart 16
#define buttonSelect 32
#define buttonB 64
#define buttonA 128
/*----------------------------------------------------------------------+
| Arduino Uno config |
+----------------------------------------------------------------------*/

// Arduino AVR Gigatron Schematic Controller PCB Gigatron
// Uno Name OUT bit CD4021 74HC595 (U39) DB9 (J4)
// ------- ------ -------- --------- ---------- ---------------- --------
// Pin 13 PORTB5 None SER_DATA 11 SER INP 14 SER 2
// Pin 12 PORTB4 7 vSync SER_LATCH 0 PAR/SER None 3
// Pin 11 PORTB3 6 hSync SER_PULSE 10 CLOCK 11 SRCLK 12 RCLK 4

#if ArduinoUno
// Pins for Gigatron
#define SER_DATA PB5
#define SER_LATCH PB4
#define SER_PULSE PB3

// Pins for PS/2 keyboard (Arduino Uno)
#define keyboardClockPin 3 // Pin 2 or 3 for IRQ
#define keyboardDataPin 4 // Any available free pin

// Link to PC/laptop
#define hasSerial 1
#endif

/*----------------------------------------------------------------------+
| Arduino Micro config |
+----------------------------------------------------------------------*/

// See also: https://forum.gigatron.io/viewtopic.php?f=4&t=33

// Arduino AVR Gigatron Schematic Controller PCB Gigatron
// Micro Name OUT bit CD4021 74HC595 (U39) DB9 (J4)
// ------- ------ -------- --------- ---------- ---------------- --------
// SCLK PORTB1 None SER_DATA 11 SER INP 14 SER 2
// MISO PORTB3 7 vSync SER_LATCH 0 PAR/SER None 3
// MOSI PORTB2 6 hSync SER_PULSE 10 CLOCK 11 SRCLK 12 RCLK 4

// --------------------+
// Reset |
// Arduino +---+ |
// Micro | O | |
// +---+ |
// |
// 2 4 6 |
// ICSP-> o o o |
// Port .o o o |
// 1 3 5 |
// --------------------+

#if ArduinoMicro

// Pins for Gigatron
#define SER_DATA PB1
#define SER_LATCH PB3
#define SER_PULSE PB2

// Pins for PS/2 keyboard (XXX These are still for Arduino Uno)
#define keyboardClockPin 3 // Pin 2 or 3 for IRQ
#define keyboardDataPin 4 // Any available free pin

// Link to PC/laptop
#define hasSerial 1
#endif

/*----------------------------------------------------------------------+
| ATtiny85 config |
+----------------------------------------------------------------------*/

// +------+
// ~RESET --|1. 8|-- Vcc
// PS/2 data PB3 --|2 7|-- PB2 Serial data out
// PS/2 clock PB4 --|3 6|-- PB1 Serial latch in
// GND --|4 5|-- PB0 Serial pulse in
// +------+
// ATtiny85

#if ATtiny85

// Pins for Gigatron
#define SER_DATA PB2
#define SER_LATCH PB1
#define SER_PULSE PB0

// Pins for PS/2 keyboard
// XXX PS2KeyBoard.h doesn't work for ATtiny yet
// because interrupts work in a different way
#define keyboardClockPin PB4
#define keyboardDataPin PB3

// Link to PC/laptop
#define hasSerial 0
#endif

/*----------------------------------------------------------------------+
| End config section |
+----------------------------------------------------------------------*/

/*
* Loader protocol
Expand All @@ -69,22 +150,28 @@ byte checksum; // Global is simplest

PS2Keyboard keyboard;

// Pins for PS/2 keyboard (Arduino Uno)
const int keyboardClockPin = 3; // Pin 2 or 3 for IRQ
const int keyboardDataPin = 4; // Any available free pin
/*
* Game controller button mapping
*/

// Keyboard
// Pin 4 PS/2 Data
// Pin 3 PS/2 Clock
#define buttonRight 1
#define buttonLeft 2
#define buttonDown 4
#define buttonUp 8
#define buttonStart 16
#define buttonSelect 32
#define buttonB 64
#define buttonA 128
// Note: The kit's controller gives inverted signals.

/*
* Setup runs once when the Arduino wakes up
*/
void setup()
{
// Enable output pin (pins are set to input by default)
PORTB |= 1<<PORTB5; // Send 1 when idle
DDRB = 1<<PORTB5;
PORTB |= 1<<SER_DATA; // Send 1 when idle
DDRB = 1<<SER_DATA;

// Open upstream communication
Serial.begin(115200);
Expand Down Expand Up @@ -148,15 +235,17 @@ void prompt()
bool detectGigatron()
{
unsigned long timeout = millis() + 85;
long T[] = {0, 0, 0, 0};
long T[2][2] = {{0, 0}, {0, 0}};

// Sample the sync signals coming out of the controller port
while (millis() < timeout)
T[(PINB >> PORTB3) & 3]++; // capture PORTB3 and PORTB4
while (millis() < timeout) {
byte pinb = PINB; // capture SER_PULSE and SER_LATCH at the same time
T[ (pinb>>SER_LATCH)&1 ][ (pinb>>SER_PULSE)&1 ]++;
}

float S = T[0] + T[1] + T[2] + T[3] + .1; // Avoid zero division (pedantic)
float vSync = (T[0] + T[1]) / ( 8 * S / 521); // Adjusted vSync signal
float hSync = (T[0] + T[2]) / (96 * S / 800); // Standard hSync signal
float S = T[0][0] + T[0][1] + T[1][0] + T[1][1] + .1; // Avoid zero division (pedantic)
float vSync = (T[0][0] + T[0][1]) / ( 8 * S / 521); // Adjusted vSync signal
float hSync = (T[0][0] + T[1][0]) / (96 * S / 800); // Standard hSync signal

// Check that vSync and hSync characteristics look normal
return 0.95 <= vSync && vSync <= 1.20 && 0.95 <= hSync && hSync <= 1.05;
Expand Down Expand Up @@ -343,7 +432,7 @@ void sendGt1Segment(word address, int len, byte data[])

// Wait for vBlank to start so we're 100% sure to skip one frame and
// the checksum resets on the other side. (This is a bit pedantic)
while (PINB & (1<<PORTB4)) // ~160 us
while (PINB & (1<<SER_LATCH)) // ~160 us
;
}

Expand All @@ -366,7 +455,7 @@ void sendController(byte value, int n)
// E.g. 4 frames = 3/60s = ~50 ms
for (int i=0; i<n; i++) {
sendFirst(value, 8);
PORTB |= 1<<PORTB5; // Send 1 when idle
PORTB |= 1<<SER_DATA; // Send 1 when idle
}

interrupts(); // So delay() can work again
Expand Down Expand Up @@ -403,15 +492,15 @@ void sendFrame(byte firstByte, byte len, word address, byte message[])
byte lastByte = -checksum; // Checksum must come out as 0
sendBits(lastByte, 8);
checksum = lastByte; // Concatenate checksums
PORTB |= 1<<PORTB5; // Send 1 when idle
PORTB |= 1<<SER_DATA; // Send 1 when idle
}

void sendFirst(byte value, byte n)
{
// Wait vertical sync NEGATIVE edge to sync with loader
while (~PINB & (1<<PORTB4)) // Ensure vSync is HIGH first
while (~PINB & (1<<SER_LATCH)) // Ensure vSync is HIGH first
;
while (PINB & (1<<PORTB4)) // Then wait for vSync to drop
while (PINB & (1<<SER_LATCH)) // Then wait for vSync to drop
;
sendBits(value, n);
}
Expand All @@ -422,16 +511,16 @@ void sendBits(byte value, byte n)
for (byte bit=1<<(n-1); bit; bit>>=1) {
// Send next bit
if (value & bit)
PORTB |= 1<<PORTB5;
PORTB |= 1<<SER_DATA;
else
PORTB &= ~(1<<PORTB5);
PORTB &= ~(1<<SER_DATA);

// Wait for bit transfer at horizontal sync POSITIVE edge.
// This timing is tight for the first bit of the first byte and
// the reason that interrupts must be disabled on the Arduino.
while (PINB & (1<<PORTB3)) // Ensure hSync is LOW first
while (PINB & (1<<SER_PULSE)) // Ensure hSync is LOW first
;
while (~PINB & (1<<PORTB3)) // Then wait for hSync to rise
while (~PINB & (1<<SER_PULSE)) // Then wait for hSync to rise
;
}
checksum += value;
Expand Down

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