From cc0685a3331ba723e7bff9540eee9b734a50ee04 Mon Sep 17 00:00:00 2001
From: jess <jess@else-if.org>
Date: Wed, 1 Apr 2026 01:29:27 -0700
Subject: [PATCH] fix: AD5941 soft-reset between measurement modes to prevent
 pH->EIS lockup

---
 main/echem.c | 6 ++++++
 main/eis.c   | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/main/echem.c b/main/echem.c
index 59f060d..cb20334 100644
--- a/main/echem.c
+++ b/main/echem.c
@@ -93,6 +93,9 @@ static uint16_t mv_to_vbias_code(float v_cell_mv)
 
 static void echem_init_lp(uint32_t rtia_reg)
 {
+    AD5940_SoftRst();
+    AD5940_Initialize();
+
     CLKCfg_Type clk;
     memset(&clk, 0, sizeof(clk));
     clk.HFOSCEn        = bTRUE;
@@ -207,6 +210,9 @@ static float read_current_ua(float rtia_ohms)
 
 static void echem_init_adc(void)
 {
+    AD5940_SoftRst();
+    AD5940_Initialize();
+
     CLKCfg_Type clk;
     memset(&clk, 0, sizeof(clk));
     clk.HFOSCEn        = bTRUE;
diff --git a/main/eis.c b/main/eis.c
index 74a2ec0..4ba43cd 100644
--- a/main/eis.c
+++ b/main/eis.c
@@ -159,6 +159,10 @@ void eis_init(const EISConfig *cfg)
     ctx.sys_clk = 16000000.0f;
     resolve_config();
 
+    /* reset to clear stale AFE state from prior measurement mode */
+    AD5940_SoftRst();
+    AD5940_Initialize();
+
     CLKCfg_Type clk;
     memset(&clk, 0, sizeof(clk));
     clk.HFOSCEn        = bTRUE;