mictoled: improve sim test data

1 files changed, 63 insertions, 0 deletions

diff --git a/mictoled/pdmgen/src/main.rs b/mictoled/pdmgen/src/main.rs
new file mode 100644
index 0000000..873f3ea
--- /dev/null
+++ b/mictoled/pdmgen/src/main.rs
@@ -0,0 +1,63 @@
+use std::{io::Write, slice};
+
+fn main() {
+    let freq_ampl_pairs : Vec<String> = std::env::args()
+        .skip(1)
+        .collect();
+
+    let freq_ampl : Vec<(f32, f32)> = freq_ampl_pairs
+        .chunks_exact(2)
+        .map(|c| {
+            (c[0].parse().expect("argument should convert to 32"),
+             c[1].parse().expect("argument should convert to 32"))
+        })
+        .collect();
+
+    println!("PDM gen with:");
+    for (f, a) in &freq_ampl {
+        println!("Freq: {} Ampl: {}", f, a);
+    }
+
+    const AUDIO_RATE : usize = 31250;
+    const INTERP : usize = 64;
+    //const PDM_RATE : usize = AUDIO_RATE * INTERP;
+
+    const AUDIO_LEN : usize = 2 * AUDIO_RATE;
+
+    let mut audio_signal = Vec::new();
+    audio_signal.resize(AUDIO_LEN, 0f32);
+    use std::f32::consts::PI;
+    for (f, a) in &freq_ampl {
+        for n in 0..AUDIO_LEN {
+            audio_signal[n] += a * f32::sin(2.0 * PI * f / (AUDIO_RATE as f32) * (n as f32));
+        }
+    }
+
+    let mut pdm_signal = Vec::with_capacity(audio_signal.len() * INTERP);
+    for samp in audio_signal {
+        let mut quant = 0i8;
+        let mut sigma = 0.0;
+        for _i in 0..INTERP {
+            let delta = samp - quant as f32;
+            sigma += delta;
+            quant = if sigma >= 0.0 { 1 } else { -1 };
+            pdm_signal.push(quant);
+        }
+    }
+
+    let fd = std::fs::File::create("pdm.npy").expect("pdm.npy should be created");
+    let mut fd = std::io::BufWriter::new(fd);
+    let slice_u8: &[u8] = unsafe {
+        slice::from_raw_parts(
+            pdm_signal.as_ptr() as *const u8,
+            pdm_signal.len(),
+        )
+    };
+    fd.write(slice_u8).expect("write to pdm.npy");
+
+    let fd = std::fs::File::create("pdm.hex").expect("pdm.hex should be created");
+    let mut fd = std::io::BufWriter::new(fd);
+    for samp in pdm_signal {
+        writeln!(&mut fd, "{}", if samp > 0 { 1 } else { 0 }).expect("write to pdm.hex");
+    }
+}