Initial commit, firmware skeleton

5 files changed, 109 insertions, 0 deletions

diff --git a/firmware/src/adc.hpp b/firmware/src/adc.hpp
new file mode 100644
index 0000000..a3bd0b0
--- /dev/null
+++ b/firmware/src/adc.hpp
@@ -0,0 +1,25 @@
+#include <array>
+#include <cstdint>
+
+namespace adc
+{
+
+struct Sample
+{
+    std::uint8_t value {0};
+    bool changed {false};
+};
+
+void
+init()
+{
+}
+
+std::array<Sample, 2>
+get_samples()
+{
+    // TODO: scale 12-bit range into MIDI 7-bit range with hysteresis
+    return std::array<Sample, 2>{{{}, {}}};
+}
+
+}
diff --git a/firmware/src/debug.hpp b/firmware/src/debug.hpp
new file mode 100644
index 0000000..856da38
--- /dev/null
+++ b/firmware/src/debug.hpp
@@ -0,0 +1,12 @@
+#include <cstdio>
+
+namespace debug
+{
+
+void
+init()
+{
+    stdio_init_all();
+}
+
+}
diff --git a/firmware/src/display.hpp b/firmware/src/display.hpp
new file mode 100644
index 0000000..e2dabf2
--- /dev/null
+++ b/firmware/src/display.hpp
@@ -0,0 +1,22 @@
+#include "hardware/i2c.h"
+
+namespace display
+{
+
+// I2C0 on GPIO8 (SDA) and GPIO9 (SCL) running at 400KHz
+constexpr auto I2C_PORT = i2c0;
+constexpr unsigned I2C_SDA = 8;
+constexpr unsigned I2C_SCL = 9;
+
+void
+init()
+{
+    i2c_init(I2C_PORT, 400*1000);
+    
+    gpio_set_function(I2C_SDA, GPIO_FUNC_I2C);
+    gpio_set_function(I2C_SCL, GPIO_FUNC_I2C);
+    gpio_pull_up(I2C_SDA);
+    gpio_pull_up(I2C_SCL);
+}
+
+}
diff --git a/firmware/src/firmware.cpp b/firmware/src/firmware.cpp
new file mode 100644
index 0000000..fc5bdd7
--- /dev/null
+++ b/firmware/src/firmware.cpp
@@ -0,0 +1,35 @@
+#include "pico/stdlib.h"
+
+#include "debug.hpp"
+#include "display.hpp"
+#include "adc.hpp"
+#include "midi.hpp"
+
+void
+update()
+{
+    for (auto const [value, changed] : adc::get_samples())
+    {
+        if (!changed) continue;
+
+        midi::send_message();
+        // update framebuffer
+    }
+
+    // send frame to display
+}
+
+[[noreturn]] int
+main()
+{
+    debug::init();
+    display::init();
+    adc::init();
+    midi::init();
+
+    while (true)
+    {
+        update();
+        sleep_ms(50);
+    }
+}
diff --git a/firmware/src/midi.hpp b/firmware/src/midi.hpp
new file mode 100644
index 0000000..c2d639a
--- /dev/null
+++ b/firmware/src/midi.hpp
@@ -0,0 +1,15 @@
+
+namespace midi
+{
+
+void
+init()
+{
+}
+
+void
+send_message()
+{
+}
+
+}