From 2d09e22ec62f73533241b0e3eff0e04ebfb7d6b3 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Fri, 13 Sep 2024 21:40:22 +0200
Subject: [PATCH] avr: "Utils_WaitNanoSecs 100000" doesn't work at 8MHz (too
 many cycles).

---
 avr/common/utils_wait_fixed.asm | 24 +++++++++++++++++++-----
 avr/modules/si7021/main.asm     |  5 +++--
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/avr/common/utils_wait_fixed.asm b/avr/common/utils_wait_fixed.asm
index 66ba62c..028774d 100644
--- a/avr/common/utils_wait_fixed.asm
+++ b/avr/common/utils_wait_fixed.asm
@@ -11,14 +11,28 @@
 
 
 ; ---------------------------------------------------------------------------
+; @routine Utils_WaitFor10MicroSecs @global
+;
 ; wait for 10 microsecs (minus cycles for call and ret).
 ;
-; IN:
-; - nothing
-; OUT:
-; - nothing
-; REGS: r22
+; @clobbers r22
 
 Utils_WaitFor10MicroSecs:
     Utils_WaitNanoSecs 10000, 7, r22            ; wait for 10us (minus RCALL and RET)
     ret
+; @end
+
+
+
+; ---------------------------------------------------------------------------
+; @routine Utils_WaitFor50MicroSecs @global
+;
+; wait for 50 microsecs (minus cycles for call and ret).
+;
+; @clobbers r22
+
+Utils_WaitFor50MicroSecs:
+    Utils_WaitNanoSecs 50000, 7, r22            ; wait for 50us (minus RCALL and RET)
+    ret
+; @end
+
diff --git a/avr/modules/si7021/main.asm b/avr/modules/si7021/main.asm
index efa15b6..e6cd350 100644
--- a/avr/modules/si7021/main.asm
+++ b/avr/modules/si7021/main.asm
@@ -294,8 +294,9 @@ si7021MeasureAny_loop:                     ; (R22)
     rcall twiSendByteExpectAck             ; (R16, R17, R18, R22)
     brcs si7021MeasureAny_gotValue         ; chip responds, receive values
     dec r14
-    breq si7021MeasureAny_error   ; timeout
-    Utils_WaitNanoSecs 100000, 0, r22
+    breq si7021MeasureAny_error            ; timeout
+    rcall Utils_WaitFor50MicroSecs         ; wait for 100usecs total
+    rcall Utils_WaitFor50MicroSecs
   rjmp si7021MeasureAny_loop
   
 si7021MeasureAny_gotValue: