From 0fd71c101cc346c1ef2ab58b0f9bf2f5ecb628ef Mon Sep 17 00:00:00 2001
From: Stefan Kratochwil <Kratochwil-LA@gmx.de>
Date: Sat, 1 Jun 2024 00:33:54 +0200
Subject: [PATCH] WIP: Reuse logic from arduino project wo make mfrc522 work.

Hint: https://github.com/miguelbalboa/rfid.git
---
 main.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 92 insertions(+), 2 deletions(-)

diff --git a/main.c b/main.c
index a90cd32..de2c5b4 100644
--- a/main.c
+++ b/main.c
@@ -59,17 +59,107 @@ void mfrc522_integration_init(void)
         mfrc522_interface_debug_print("ERR: %s failed: %d\n", __FUNCTION__, init_retval);
     }
 
+    // Set IRQ pin of MFRC522 to CMOS, enable irq on pico on success
     uint8_t irq_pin_type_ret = mfrc522_set_interrupt_pin_type(&ctx, MFRC522_INTERRUPT_PIN_TYPE_STANDARD_CMOS);
     if (irq_pin_type_ret != 0) {
-        mfrc522_interface_debug_print("ERR: Could not set interrupt pin type.");
+        mfrc522_interface_debug_print("ERR: Could not set interrupt pin type.\n");
     }
     else
     {
         mfrc522_integration_irq_init(&ctx);
     }
 
-    // TODO Clear all interrupt bits here?
+    // Set rf uart to 106000 baud (tx/rx)
+    uint8_t set_tx_speed_ret = mfrc522_set_tx_speed(&ctx, MFRC522_SPEED_106_KBD);
+    if (set_tx_speed_ret != 0) {
+        mfrc522_interface_debug_print("ERR: could not set rf tx speed\n");
+    }
 
+    uint8_t set_rx_speed_ret = mfrc522_set_rx_speed(&ctx, MFRC522_SPEED_106_KBD);
+    if (set_rx_speed_ret != 0) {
+        mfrc522_interface_debug_print("ERR: could not set rf rx speed\n");
+    }
+
+    // Set modulation width to initial default value (datasheet section 9.3.3.4)
+    uint8_t set_modw_ret = mfrc522_set_modulation_width(&ctx, 0x26);
+    if (set_modw_ret != 0) {
+        mfrc522_interface_debug_print("ERR: could not set modulation width register\n");
+    }
+
+    // Timer setup. First set timer to auto, then set prescaler to 0xA9
+    uint8_t set_tauto_ret = mfrc522_set_timer_auto(&ctx, MFRC522_BOOL_TRUE);
+    if (set_tauto_ret != 0) {
+        mfrc522_interface_debug_print("ERR: Could not set timer to auto\n");
+    }
+
+    uint8_t set_tprescaler = mfrc522_set_timer_prescaler(&ctx, (uint16_t) 0xA9);
+    if (set_tprescaler != 0) {
+        mfrc522_interface_debug_print("ERR: Could not set timer prescaler\n");
+    }
+
+    // Timer setup. Configure reload registers (hi and lo)
+    uint8_t set_treload = mfrc522_set_timer_reload(&ctx, (uint16_t) 0x3E8);
+    if (set_treload != 0) {
+        mfrc522_interface_debug_print("ERR: Could not set timer reload value");
+    }
+
+    // A magic modulation setting: force ASK 100% - whatever that is..
+    uint8_t force_100ask_ret = mfrc522_set_force_100_ask(&ctx, MFRC522_BOOL_TRUE);
+    if (force_100ask_ret != 0) {
+        mfrc522_interface_debug_print("ERR: Could not force 100\% ASK modulation\n");
+    }
+
+    // More settings for the mode register (crc setup, wait for rf field)
+    uint8_t set_modereg_msbfirst_ret = mfrc522_set_crc_msb_first(&ctx, MFRC522_BOOL_FALSE);
+    if (set_modereg_msbfirst_ret != 0) {
+        mfrc522_interface_debug_print("ERR: Could not set crc to msb first\n");
+    }
+    uint8_t set_modereg_txwaitrf_ret = mfrc522_set_tx_wait_rf(&ctx, MFRC522_BOOL_TRUE);
+    if (set_modereg_txwaitrf_ret != 0) {
+        mfrc522_interface_debug_print("ERR: Could not make transmitter wait for rf field\n");
+    }
+    uint8_t set_modereg_polmfin_ret = mfrc522_set_mfin_polarity(&ctx, MFRC522_MFIN_POLARITY_HIGH);
+    if (set_modereg_polmfin_ret != 0)
+    {
+        mfrc522_interface_debug_print("ERR: Could not set mfin polarity\n");
+    }
+    uint8_t set_modereg_crcpres_ret = mfrc522_set_crc_preset(&ctx, MFRC522_CRC_PRESET_6363);
+    if (set_modereg_crcpres_ret != 0) {
+        mfrc522_interface_debug_print("ERR: Could not set crc preset value\n");
+    }
+
+    // Enable antenna
+    uint8_t set_ant_invrx2_ret = mfrc522_set_antenna_driver(&ctx, MFRC522_ANTENNA_DRIVER_INV_TX2_RF_ON, MFRC522_BOOL_TRUE);
+    if (set_ant_invrx2_ret != 0)
+    {
+        mfrc522_interface_debug_print("ERR: Could not enable tx2 invert\n");
+    }
+    uint8_t enable_ant_tx2rf_ret = mfrc522_set_antenna_driver(&ctx, MFRC522_ANTENNA_DRIVER_TX2_RF, MFRC522_BOOL_TRUE);
+    if (enable_ant_tx2rf_ret != 0)
+    {
+        mfrc522_interface_debug_print("ERR: Could not enable tx2 rf\n");
+    }
+    uint8_t enable_ant_tx1rf_ret = mfrc522_set_antenna_driver(&ctx, MFRC522_ANTENNA_DRIVER_TX1_RF, MFRC522_BOOL_TRUE);
+    if (enable_ant_tx1rf_ret != 0)
+    {
+        mfrc522_interface_debug_print("ERR: Could not enable tx1 rf\n");
+    }
+
+    // Enable RX interrupt on rf side   XXX Are we doing the right thing?!?
+    uint8_t set_irq_invert_ret = mfrc522_set_interrupt1_pin_invert(&ctx, MFRC522_BOOL_TRUE);
+    if (set_irq_invert_ret != 0)
+    {
+        mfrc522_interface_debug_print("ERR: Could not invert irq pin\n");
+    }
+
+    // Enable RX interrupt
+    uint8_t en_rx_irq = mfrc522_set_interrupt1(&ctx, MFRC522_INTERRUPT1_RX , MFRC522_BOOL_TRUE);
+    if (en_rx_irq != 0)
+    {
+        mfrc522_interface_debug_print("ERR: Could not enable rx interrupt on rf side\n");
+    }
+
+    // Enable analog section of the reader
     uint8_t analog_enable_retval = mfrc522_set_receiver_analog(&ctx, MFRC522_BOOL_TRUE);
     if (analog_enable_retval != 0) {
         mfrc522_interface_debug_print("ERR: Enabling analog receiver failed: %d\n", analog_enable_retval);