Merge branch '32-add-support-for-rpi-model' into 'develop'

Add experimental suport for SPI RASPBERRYPI

Closes #32

See merge request internal/sw-design/libtropic!33

src/lt_l1.c

@@ -42,6 +42,20 @@ lt_ret_t lt_l1_read(lt_handle_t *h, const uint32_t max_len, const uint32_t timeo
 
         // Try to read CHIP_STATUS
         lt_l1_spi_csn_low(h);
+#ifdef EXPERIMENTAL_SPI_RASPBERRYPI
+        // store the byte which was initally in l2_buff
+        uint8_t store_byte = h->l2_buff[0];
+        // put raspberry command byte there
+        h->l2_buff[0] = PUT READ BYTE HERE;
+        // do transmit of that one command
+        if (lt_l1_spi_transfer(h, 0, 1, timeout) != LT_OK)
+        {
+            lt_l1_spi_csn_high(h);
+            return LT_L1_SPI_ERROR;
+        }
+        // put previous byte back to buffer and continue as usually
+        h->l2_buff[0] = store_byte;
+#endif
         if (lt_l1_spi_transfer(h, 0, 1, timeout) != LT_OK)
         {
             lt_l1_spi_csn_high(h);