From 2b915a3e595c46f809971f611115a549ba2f11d6 Mon Sep 17 00:00:00 2001
From: Mirko Scholz <srtlg@users.noreply.github.com>
Date: Thu, 10 Sep 2020 19:59:57 +0200
Subject: [PATCH] decreased accuracy so that the real hardware is useful at 33
 MHz

---
 Makefile                     |  4 ++--
 src/decn/decn.c              | 14 ++++++--------
 src/decn/decn_tests_trig.cpp | 14 +++++++-------
 3 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/Makefile b/Makefile
index c06986a..ad56bce 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,10 @@
 SDCC ?= sdcc
 STCCODESIZE ?= 13312
-SDCCOPTS ?= --code-size $(STCCODESIZE) --xram-size 256 --idata-loc 0x80
+SDCCOPTS ?= --code-size $(STCCODESIZE) --xram-size 256 --idata-loc 0x70
 #SDCCOPTS ?= --code-size $(STCCODESIZE) --xram-size 256 --stack-auto --model-large
 FLASHFILE ?= main.hex
 LARGE_LDFLAGS += -L/usr/share/sdcc/lib/large/
-# CFLAGS += -DSTACK_DEBUG -DSHOW_STACK # write the stack pointer to P3_4
+# CFLAGS += -DSTACK_DEBUG # write the stack pointer to P3_4
 
 SRC = src/lcd.c src/key.c src/utils.c src/decn/decn.c src/calc.c src/stack_debug.c
 
diff --git a/src/decn/decn.c b/src/decn/decn.c
index 23c783f..dbbada1 100644
--- a/src/decn/decn.c
+++ b/src/decn/decn.c
@@ -1339,8 +1339,8 @@ void sincos_decn(const uint8_t sincos_arctan) {
 		copy_decn(&THETA, &AccDecn);
 		copy_decn(&COS, &DECN_1);
 		set_dec80_zero(&SIN);
-		// 0.0 00 05
-		SIN.lsu[2] = 5;
+		// 0.0 00 5
+		SIN.lsu[2] = 50;
 		negate_decn(&SIN);
 	}
 	do {
@@ -1355,29 +1355,27 @@ void sincos_decn(const uint8_t sincos_arctan) {
 				break;
 			}
 		}
-		// COS = COS - SIN / 10000
+		// COS = COS - SIN / 1000
 		copy_decn(&AccDecn, &COS);
 		copy_decn(&BDecn, &SIN);
 		shift_right(&BDecn);
 		shift_right(&BDecn);
 		shift_right(&BDecn);
-		shift_right(&BDecn);
 		negate_decn(&BDecn);
 		add_decn();
 		copy_decn(&COS, &AccDecn);
-		// SIN = SIN + COS / 10000
+		// SIN = SIN + COS / 1000
 		copy_decn(&AccDecn, &SIN);
 		copy_decn(&BDecn, &COS);
 		shift_right(&BDecn);
 		shift_right(&BDecn);
 		shift_right(&BDecn);
-		shift_right(&BDecn);
 		add_decn();
 		copy_decn(&SIN, &AccDecn);
-		// THETA = THETA -/+ 0.0 00 1
+		// THETA = THETA -/+ 0.0 01
 		copy_decn(&AccDecn, &THETA);
 		set_dec80_zero(&BDecn);
-		BDecn.lsu[2] = 10;
+		BDecn.lsu[1] = 1;
 		if (!sincos_arctan) negate_decn(&BDecn);
 		add_decn();
 		copy_decn(&THETA, &AccDecn);
diff --git a/src/decn/decn_tests_trig.cpp b/src/decn/decn_tests_trig.cpp
index 28236ae..534e7bf 100644
--- a/src/decn/decn_tests_trig.cpp
+++ b/src/decn/decn_tests_trig.cpp
@@ -80,7 +80,7 @@ const char * const pi_quarted = ".7853981633974483096";
 
 TEST_CASE("sin") {
 	sin_test("0.1", 0);
-	sin_test("0.05", 0);
+	sin_test("0.05", 0, 1e-2);
 	sin_test("0.01", 0, -1);
 	sin_test("0.001", 0, -1);
 	sin_test("0.0001", 0, -1);
@@ -147,8 +147,8 @@ TEST_CASE("cos") {
 
 TEST_CASE("tan") {
 	tan_test("0.1", 0);
-	tan_test("0.05", 0);
-	tan_test("0.01", 0);
+	tan_test("0.05", 0, 1e-2);
+	tan_test("0.01", 0, 5e-2);
 	tan_test("0.001", 0, -1);
 	tan_test("0.0001", 0, -1);
 	tan_test("0.00001", 0, -1);
@@ -165,8 +165,8 @@ TEST_CASE("tan") {
 }
 
 TEST_CASE("arctan") {
-	atan_test("0.001", 0);
-	atan_test("-0.001", 0);
+	atan_test("0.001", 0, -1, 2e-3);
+	atan_test("-0.001", 0, -1, 2e-3);
 	atan_test("0.7", 0);
 	atan_test("-0.7", 0);
 	atan_test("0.1", 0);
@@ -185,8 +185,8 @@ TEST_CASE("arcsin") {
 	asin_test("-0.001", 0, -1);
 	asin_test("0.7", 0);
 	asin_test("-0.7", 0);
-	asin_test("0.1", 0);
-	asin_test("-0.1", 0);
+	asin_test("0.1", 0, 1e-2);
+	asin_test("-0.1", 0, 1e-2);
 	asin_test("0.9", 0);
 	asin_test("-0.9", 0);
 }