Changeset 88a38a8 in avrstuff for kbd/pcw2hid/code/protocol.cpp

Timestamp:

Feb 7, 2023, 11:43:54 PM (16 months ago)

Author:

PulkoMandy <pulkomandy@…>

Branches:

main

Children:

53cf5f5

Parents:

8d96947

Message:

pcw2hid: first working version

Remaining problem: ESC seems to be pressed with alt and shift, I don't
see why. Probqbly should have a key acting as numlock, otherwise there's
no way to have cursor keys...

This message is typed with a PCW keyboard :D

File:

• kbd/pcw2hid/code/protocol.cpp (modified) (5 diffs)

kbd/pcw2hid/code/protocol.cpp

@@ -1 +1 @@
 #include <avr/io.h>
+#include <avr/interrupt.h>
 
 #include <stdbool.h>
@@ -11 +12 @@
 #define PCW_DAT_A  (1 << 1)
 
-static uint8_t data;
-static uint8_t address;
+uint8_t matrix[16];
 
-static uint8_t oldv;
-static uint8_t newv;
+static uint16_t scanbyte()
+{
+        uint8_t pulses = 0;
+        uint8_t oldv, newv;
+        uint16_t rxbuffer = 0;
 
-static uint8_t pulses;
-
-static uint8_t kmatrix[16];
-
-uint8_t scanbyte()
-{
-        pulses = 0;
-        address = 0;
-
+        // This is a bit timing critical so don't be interrupted while we do it
+        cli();
         oldv = PCW_PIN;
 
-        for (int i = 0; i < 2048; i++) {
+        for (;;) {
                 newv = PCW_PIN;
 
@@ -37 +33 @@
                                 // We are not in sync, start over
                                 pulses = 0;
-                                address = 0;
+                                rxbuffer = 0;
                         }
                         if (((newv & PCW_DAT_A) == 0) && ((oldv & PCW_DAT_A) != 0)) {
-                                pulses++;
-                        }
-                } else if (pulses < 6) {
-                        // Receiving address (4 bits)
-                        if (((newv & PCW_CLK_A) == 0) && ((oldv & PCW_CLK_A) != 0)) {
-                                address = (address << 1) | ((newv & PCW_DAT_A) ? 1 : 0);
                                 pulses++;
                         }
@@ -51 +41 @@
                         // Receiving data (8 bits)
                         if (((newv & PCW_CLK_A) == 0) && ((oldv & PCW_CLK_A) != 0)) {
-                                data = (data << 1) | ((newv & PCW_DAT_A) ? 1 : 0);
+                                rxbuffer = (rxbuffer << 1);
+                                if (newv & PCW_DAT_A)
+                                        rxbuffer |= 1;
                                 pulses++;
-                        }
 
-                        // If we reached the last bit, we can stop
-                        if (pulses >= 10) {
-                                kmatrix[address] = data;
-                                return address;
+                                // If we reached the last bit, we can stop
+                                if (pulses == 14) {
+                                        // We can be interrupted again.
+                                        sei();
+                                        return rxbuffer;
+                                }
                         }
                 }
@@ -64 +57 @@
                 oldv = newv;
         }
-
-        // TODO set up some error LED or something?
-        return 255;
 }
 
-extern "C" uint8_t* scanall()
+extern "C" void scanall()
 {
-        uint8_t address;
-
-        do {
-                address = scanbyte();
-        // } while ((address < 15) && ((kmatrix[15] & 0x80) != 0));
-        } while ((address != 10) && ((kmatrix[15] & 0x80) != 0));
-        // nothing interesting past row 10, so stop scanning there.
-
-        return kmatrix;
+        uint16_t rxbuffer;
+        
+        for (int i = 0; i < 17; i++) {
+                rxbuffer = scanbyte();
+                matrix[rxbuffer >> 8] = rxbuffer & 0xFF;
+        }
 }
 
 extern "C" void PCW_Init() {
         // GrIP input
-        PCW_PORT = 0xFF; // Enable pull-ups
-        PCW_DDR = 0;  // Port as input
+        PCW_PORT |= 0x3; // Enable pull-ups
+        PCW_DDR &= 0xFC;  // Port as input
 }