1 files changed, 69 insertions, 0 deletions
diff --git a/fw/test_uart.c b/fw/test_uart.c
new file mode 100644
index 0000000..4e18dc5
--- /dev/null
+++ b/fw/test_uart.c
@@ -0,0 +1,69 @@
+#include <pic16f84a.h>
+
+typedef unsigned char uint8_t;
+
+__sfr __at(0x70) UART_TX;
+__sfr __at(0x71) UART_RX;
+__sfr __at(0x72) UART_STATUS;
+
+static volatile uint8_t _d0, _d1, _d2;
+static uint8_t counter;
+
+static void delay(void) {
+    _d0 = 0;
+    do {
+        _d1 = 0;
+        do {
+            _d2 = 0;
+            do { _d2++; } while (_d2 != 0);
+        } while (++_d1 != 30);
+        _d0++;
+    } while (_d0 != 10);
+}
+
+static void uart_send(uint8_t byte) {
+    while (UART_STATUS & 0x01); 
+    UART_TX = byte;
+}
+
+// Keep this ONLY for literal strings (ROM)
+static void uart_puts_rom(const char *s) {
+    while (*s) {
+        uart_send((uint8_t)*s);
+        s++;
+    }
+}
+
+void main(void) {
+    counter = 0;
+    uart_puts_rom("counter\r\n");
+
+    while (1) {
+        uint8_t v = counter;
+        uint8_t started = 0;
+
+
+        uart_puts_rom("\r");
+		uart_puts_rom("\x1B[K");        
+
+        uart_send('C');
+        uart_send(':');
+
+        // Hundreds
+        if (v >= 200) { uart_send('2'); v -= 200; started = 1; }
+        else if (v >= 100) { uart_send('1'); v -= 100; started = 1; }
+
+        // Tens
+        {
+            uint8_t tens = '0';
+            while (v >= 10) { v -= 10; tens++; }
+            if (started || tens != '0') { uart_send(tens); }
+        }
+
+        // Units (always)
+        uart_send(v + '0');
+
+        counter++;
+        delay();
+    }
+}