From d09e9c95fdde8b4df3b87883d4ba74bae87228ae Mon Sep 17 00:00:00 2001
From: Andreas Eversberg <jolly@eversberg.eu>
Date: Sun, 27 Aug 2023 11:52:53 +0200
Subject: [PATCH] C-Netz: Make memory card emulation work with AEG OLYMPIA
 phone

Now it is ok to have the first clock pulse after reset. The software
does not care. At least there must be a clock after rising the reset.
---
 extra/simulator/simulator.ino | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/extra/simulator/simulator.ino b/extra/simulator/simulator.ino
index 06b3af1..995497f 100644
--- a/extra/simulator/simulator.ino
+++ b/extra/simulator/simulator.ino
@@ -17,11 +17,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/* NOTE: Reset must be an input pin, not the reset of the controller.
+ * The clock pulse must be detected during reset.
+ */
 #if defined(__AVR_ATtiny85__)
 #define RST_PIN  2
 #define CLK_PIN  3
 #define DATA_PIN 4
-#error UNTESTED!
 #else
 #define CLK_PIN  5
 #define RST_PIN  6
@@ -29,15 +31,14 @@
 #endif
 
 uint8_t card_data[] = {
-
+/* Example: Service card for AEG OLYMPIA. */
 0xff, 0xf7, 0x5c, 0xff, 0xff, 0xff, 0xff, 0xff,
-0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x4b, 0x90,
-0x5f, 0x25, 0x07, 0x0c, 0x00, 0x00, 0xfe, 0xfd,
+0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x47, 0x38,
+0x78, 0x28, 0x07, 0x8c, 0xc7, 0x03, 0xfe, 0xfd,
 0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00,
 0x00, 0x00, 0x00, 0x00,
-
 };
 
 volatile uint8_t *rst_in, *clk_in, *data_in, *data_out, *data_mode;
@@ -70,6 +71,8 @@ void setup()
   data_out = portOutputRegister(port);
   data_in = portInputRegister(port);
   *data_mode |= data_bit; /* output */
+  /* wait for reset */
+  while (!(*rst_in & rst_bit));
 }
 
 uint8_t byte_count;
@@ -78,22 +81,14 @@ uint8_t bit_count;
 void loop()
 {
 reset:
+  /* initial reset state */
   byte_count = 0;
   bit_count = 0;
-
-  /* wait for reset pulse */
-  while (!(*rst_in & rst_bit));
-  /* now we have reset, so we wait for clock pulse */
-  while (!(*clk_in & clk_bit)) {
-    /* if we lost reset, go to start */
-    if (!(*rst_in & rst_bit))
-      goto reset;
-  }
-  while ((*clk_in & clk_bit)) {
-    /* if we lost reset, go to start */
-    if (!(*rst_in & rst_bit))
-      goto reset;
-  }
+  *data_out |= data_bit; /* high */
+  /* now we have reset, so we wait for the first clock pulse */
+  while (!(*clk_in & clk_bit));
+  while ((*clk_in & clk_bit));
+  /* wait for reset to become low, if not already before first clock pulse (AEG phone) */
   while ((*rst_in & rst_bit));
 
 next_bit: