From 7d83f5de82aaf23663585e17561760507e7c15aa Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Sun, 4 Apr 2021 17:08:19 +0200
Subject: [PATCH] adaptations to lf hitag..

---
 armsrc/lfadc.c | 50 ++++++++++++++++++++++++++++++++++++++++++--------
 armsrc/lfadc.h |  1 +
 2 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/armsrc/lfadc.c b/armsrc/lfadc.c
index 1fb1bccde..037481ba7 100644
--- a/armsrc/lfadc.c
+++ b/armsrc/lfadc.c
@@ -52,9 +52,12 @@ bool lf_test_periods(size_t expected, size_t count) {
 //////////////////////////////////////////////////////////////////////////////
 // Low frequency (LF) adc passthrough functionality
 //////////////////////////////////////////////////////////////////////////////
-static uint8_t previous_adc_val = 0;
+static uint8_t previous_adc_val = 0; //0xFF;
 static uint8_t adc_avg = 0;
 
+uint8_t get_adc_avg(void) {
+    return adc_avg;
+}
 void lf_sample_mean(void) {
     uint8_t periods = 0;
     uint32_t adc_sum = 0;
@@ -66,20 +69,44 @@ void lf_sample_mean(void) {
     }
     // division by 32
     adc_avg = adc_sum >> 5;
+    previous_adc_val = adc_avg;
 
     if (DBGLEVEL >= DBG_EXTENDED)
         Dbprintf("LF ADC average %u", adc_avg);
 }
 
 static size_t lf_count_edge_periods_ex(size_t max, bool wait, bool detect_gap) {
+
+#define LIMIT_DEV  20
+
+    // timeout limit to 100 000 w/o 
+    uint32_t timeout = 100000;
     size_t periods = 0;
-    uint8_t avg_peak = adc_avg + 3, avg_through = adc_avg - 3;
+    uint8_t avg_peak = adc_avg + LIMIT_DEV;
+    uint8_t avg_through = adc_avg - LIMIT_DEV;
 
     while (BUTTON_PRESS() == false) {
+        WDT_HIT();
+
+        timeout--;
+        if (timeout == 0) {
+            return 0;
+        }
+
+        if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
+            AT91C_BASE_SSC->SSC_THR = 0x00;
+            continue;
+        }
+
         if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-            volatile uint8_t adc_val = AT91C_BASE_SSC->SSC_RHR;
+
             periods++;
 
+            // reset timeout
+            timeout = 100000;
+
+            volatile uint8_t adc_val = AT91C_BASE_SSC->SSC_RHR;
+
             if (g_logging) logSampleSimple(adc_val);
 
             // Only test field changes if state of adc values matter
@@ -94,21 +121,28 @@ static size_t lf_count_edge_periods_ex(size_t max, bool wait, bool detect_gap) {
                 } else {
                     // Trigger on a modulation swap by observing an edge change
                     if (rising_edge) {
+
                         if ((previous_adc_val > avg_peak) && (adc_val <= previous_adc_val)) {
                             rising_edge = false;
                             return periods;
                         }
+
                     } else {
+
                         if ((previous_adc_val < avg_through) && (adc_val >= previous_adc_val)) {
                             rising_edge = true;
                             return periods;
                         }
+
                     }
-                }
+                }                
             }
+
             previous_adc_val = adc_val;
 
-            if (periods >= max) return 0;
+            if (periods >= max) {
+                return 0;
+            }
         }
     }
 
@@ -169,10 +203,10 @@ void lf_init(bool reader, bool simulate) {
         FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
     } else {
         if (simulate)
-//            FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
             FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC);
         else
             // Sniff
+            //FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC);
             FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT  | FPGA_LF_EDGE_DETECT_TOGGLE_MODE);
 
     }
@@ -185,10 +219,10 @@ void lf_init(bool reader, bool simulate) {
 
     // When in reader mode, give the field a bit of time to settle.
     // 313T0 = 313 * 8us = 2504us = 2.5ms  Hitag2 tags needs to be fully powered.
-    if (reader) {
+//    if (reader) {
         // 10 ms
         SpinDelay(10);
-    }
+//    }
 
     // Steal this pin from the SSP (SPI communication channel with fpga) and use it to control the modulation
     AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
diff --git a/armsrc/lfadc.h b/armsrc/lfadc.h
index 66c6da534..ee2ffbbab 100644
--- a/armsrc/lfadc.h
+++ b/armsrc/lfadc.h
@@ -17,6 +17,7 @@
 
 extern bool g_logging;
 
+uint8_t get_adc_avg(void);
 void lf_sample_mean(void);
 bool lf_test_periods(size_t expected, size_t count);
 size_t lf_count_edge_periods(size_t max);