Do not get all the correct device

[Tamanar]

This is directly linked to my previous issue #1
The library does give me 3 different devices. But it gives me the same device twice.

It detects twice the DS18B20 and only 1 of the 2 DS2408.

Does the problem come from the research protocol?

I tried with 3 different cards, and I got the same issue on all the cards.

Here's a snippet of my code

    ow_init_t ow_init_struct;
    ow_init_struct.tim_handle = &htim2;
    ow_init_struct.gpio = ONE_WIRE_GPIO_Port;
    ow_init_struct.pin = ONE_WIRE_Pin;
    ow_init_struct.tim_cb = one_wire_timer_callback;
    ow_init_struct.done_cb = NULL;   // Optional: callback when transfer is done, or can use NULL
    ow_init_struct.rom_id_filter = 0;        // 0 = Accept All, or use a value. (Available if OW_MAX_DEVICE > 1) 

    ow_init(&one_wire_handle, &ow_init_struct);

    ow_update_rom_id(&one_wire_handle);
    while (ow_is_busy(&one_wire_handle));
    osDelay(pdMS_TO_TICKS(10));

[Tamanar]

When I try to use rom_id_filter = 0x29 to get all of the DS2408, I only get one device

[Tamanar]

I found a way to fix my issue.
In the case 11 of ow_state_search, I also clear the bit explicitly.

 case 11:
    if (handle->search.val == OW_VAL_1)
    {
      __HAL_TIM_SET_AUTORELOAD(handle->config.tim_handle, OW_TIM_WRITE_LOW - 1);
      handle->search.rom_id[handle->buf.bit_idx / 8] |= (1 << (handle->buf.bit_idx % 8));
    }
    else
    {
      __HAL_TIM_SET_AUTORELOAD(handle->config.tim_handle, OW_TIM_WRITE_HIGH - 1);
        // CLEAR THE BIT EXPLICITLY
        handle->search.rom_id[handle->buf.bit_idx / 8] &= ~(1 << (handle->buf.bit_idx % 8));
    }

Also, I do not reset the ROM ID once the ROM is thing in the case 12,

if (handle->buf.bit_idx == 64)
    {
      /* full ROM read */
      handle->buf.bit_idx = 0;
      handle->buf.bit_ph = 0;
      if (ow_crc(handle->search.rom_id, 7) == handle->search.rom_id[7])
      {
        /* ROM ID Filter not enabled */
        if (handle->rom_id_filter == 0)
          {
              memcpy(&handle->rom_id[handle->rom_id_found], handle->search.rom_id, 8);
              handle->rom_id_found++;
          }
        /* Selected ROM ID Filter */
        else if (handle->rom_id_filter == handle->search.rom_id[0])
        {
          memcpy(&handle->rom_id[handle->rom_id_found], handle->search.rom_id, 8);
          handle->rom_id_found++;
      }
      }
      //HERE \|/
      //memset(handle->search.rom_id, 0, 8);
      
      /* update discrepancy */
      handle->search.last_discrepancy = handle->search.last_zero;
      handle->search.last_zero = 0;

Three devices with two DS2408 found (family ID 0x29)

[adron-s]

I encountered the same problem for DS18B20 - when I have 3 or more devices.
The above fix isn't entirely correct. It didn't work for me. Here's the correct fix:

diff --git a/lib/ow/ow.c b/lib/ow/ow.c
index d4e4173..5be85e8 100644
--- a/lib/ow/ow.c
+++ b/lib/ow/ow.c
@@ -835,7 +835,12 @@ __STATIC_FORCEINLINE void ow_state_search(ow_t *handle)
       if (bit_number < handle->search.last_discrepancy)
       {
         /* repeat previous path */
-        bit_choice = (handle->search.rom_id[handle->buf.bit_idx / 8] >> (handle->buf.bit_idx % 8)) & 0x01;
+                               if (handle->rom_id_found > 0) {
+                                       bit_choice = (handle->search.last_found_rom_id[handle->buf.bit_idx / 8] >> (handle->buf.bit_idx % 8)) & 0x01;
+                               } else {
+                                       handle->error = OW_ERR_ROM_ID;
+                                       ow_stop(handle);
+                               }
       }
       else if (bit_number == handle->search.last_discrepancy)
       {
@@ -895,12 +900,14 @@ __STATIC_FORCEINLINE void ow_state_search(ow_t *handle)
         if (handle->rom_id_filter == 0)
         {
           memcpy(&handle->rom_id[handle->rom_id_found], handle->search.rom_id, 8);
+          memcpy(&handle->search.last_found_rom_id, handle->search.rom_id, 8);
           handle->rom_id_found++;
         }
         /* Selected ROM ID Filter */
         else if (handle->rom_id_filter == handle->search.rom_id[0])
         {
           memcpy(&handle->rom_id[handle->rom_id_found], handle->search.rom_id, 8);
+          memcpy(&handle->search.last_found_rom_id, handle->search.rom_id, 8);
           handle->rom_id_found++;
         }
       }
diff --git a/lib/ow/ow.h b/lib/ow/ow.h
index 458b7f3..83c7bb0 100644
--- a/lib/ow/ow.h
+++ b/lib/ow/ow.h
@@ -149,6 +149,7 @@ typedef struct __PACKED
   uint8_t                   last_zero;
   uint8_t                   last_device_flag;
   uint8_t                   rom_id[8];
+  uint8_t                   last_found_rom_id[8];
 
 } ow_search_t;
 #endif