Rebuild DAC and first functioning PoC

By just counting the gpio mask up, we can see the different voltages update they should :^)

src/main.cpp

@@ -1,22 +1,25 @@
-/**
- * Copyright (c) 2022 Raspberry Pi (Trading) Ltd.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#include "pico/cyw43_arch.h"
+#include "hardware/gpio.h"
 #include "pico/stdlib.h"
+#include <cstdint>
+#include <cstdio>
+#include <pico/time.h>
+
+constexpr static uint start_pin = 2;
+constexpr static uint pin_mask = (0xFFF) << start_pin;
 
 int main() {
   stdio_init_all();
-  if (cyw43_arch_init()) {
-    printf("Wi-Fi init failed");
-    return -1;
+
+  for (uint offset{}; offset != 14; ++offset) {
+    auto const pin = start_pin + offset;
+    gpio_init(pin);
+    gpio_set_dir(pin, GPIO_OUT);
   }
-  while (true) {
-    cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
-    sleep_ms(500);
-    cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 0);
-    sleep_ms(500);
+
+  for (uint16_t pixel{};; ++pixel) {
+    auto const set_mask = (pixel & 0xFFF) << start_pin;
+    printf("Set mask=%03x", pixel);
+    gpio_put_masked(pin_mask, set_mask);
+    sleep_ms(100);
   }
 }