From 83731f77e0bf7363e5def58d50974dba6c819da3 Mon Sep 17 00:00:00 2001
From: Hubald Verzijl <hubald@hubald.nl>
Date: Thu, 28 Aug 2025 11:33:33 +0200
Subject: [PATCH] Minor improvements

---
 src/impedance.rs | 4 ++--
 src/main.rs      | 7 +------
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/src/impedance.rs b/src/impedance.rs
index 5163bba..8a37544 100644
--- a/src/impedance.rs
+++ b/src/impedance.rs
@@ -47,7 +47,7 @@ impl ImpedanceSetup {
             .adc_mux_n(MUXSELN::HsTiaNeg)
             .adc_mux_p(MUXSELP::HsTiaPos)
             .ctiacon(CTIACON::C32)
-            .rtiacon(RTIACON::R5k)
+            .rtiacon(RTIACON::R1k)
             .sinc3osr(SINC3OSR::R5)
             .sinc2osr(SINC2OSR::R178)
             .adcsamplerate(ADCSAMPLERATE::R800kHz)
@@ -92,7 +92,7 @@ impl ImpedanceSetup {
         self.ad5940.sequencer_enable(true).await;
 
         self.ad5940.wgfcw(frequency).await;
-        let wg_amplitude = 557; // 2047 is the maximum amplitude for a 12-bit DAC --> 1.62V peak-to-peak
+        let wg_amplitude = 2047; // 2047 is the maximum amplitude for a 12-bit DAC --> 1.62V peak-to-peak
         self.ad5940.write_reg(Register::WGAMPLITUDE, wg_amplitude).await.unwrap();
 
         // Rcal
diff --git a/src/main.rs b/src/main.rs
index 8a62ebe..e41114a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -230,12 +230,7 @@ const RCAL_VAL: f32 = 1000.0;
 
 /// Convert raw 18-bit 2's complement value to signed i32
 fn sign_extend_18bit(val: u32) -> i32 {
-    let masked = val & 0x3FFFF;
-    if masked & (1 << 17) != 0 {
-        (masked | 0xFFFC0000) as i32
-    } else {
-        masked as i32
-    }
+    ((val << 14) as i32) >> 14
 }
 
 /// Calculate magnitude and phase of Rz using Rcal reference