nRF52832 UICR serial number programming

[ranger3]

In firmware I can read the programmed UICR serial number as follows: -

uint32_t serial;

memcpy(&serial, (uint32_t*)0x10001080, 4);

Is it possible to program the UICR from within the firmware during runtime?

Using the reverse  - memcpy( (uint32_t*)0x10001080, 4) doesn't work.

I would like to send a command to the nRF52 containing the serial number and write it to the UICR register.

[ranger3]

Thanks for your answer. I'm getting closer now. With the following code: -

 err_code = sd_softdevice_disable();

 if( err_code == NRF_SUCCESS )
 {
 // Enable write mode.
 NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Een<<NVMC_CONFIG_WEN_Pos;
 while(NRF_NVMC->READY == NVMC_READY_READY_Busy){}

 // write value to the register
 NRF_UICR->CUSTOMER[0] = serial;

 // Disable flash writing
 NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren<<NVMC_CONFIG_WEN_Pos;
 while(NRF_NVMC->READY == NVMC_READY_READY_Busy){}

 }
 
 // now reboot the nRF52 - there is no return from this command!
 NVIC_SystemReset();

All steps work, and the device reboots successfully, but the register value has not changed. I have read in other threads that after writing to the UICR and before restarting the softDevice needs to be re-enabled using sd_softdevice_enable(). Is this the case?

[Einar Thorsrud]

Hi,

You need to adjust the code like this (how you enable and disable flash writing):

// Enable write mode.
NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

// write value to the register
NRF_UICR->CUSTOMER[0] = serial;

// Disable flash writing
NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

This works for me when modifying the beacon example in SDK 17.0.2 to test, as shown by this diff:

Fullscreen 4747.main.c.diff Download

diff --git a/examples/ble_peripheral/ble_app_beacon/main.c b/examples/ble_peripheral/ble_app_beacon/main.c
index eebe67a..bebdf8b 100644
--- a/examples/ble_peripheral/ble_app_beacon/main.c
+++ b/examples/ble_peripheral/ble_app_beacon/main.c
@@ -57,6 +57,8 @@
 #include "ble_advdata.h"
 #include "app_timer.h"
 #include "nrf_pwr_mgmt.h"
+#include "nrf_sdm.h"
+#include "nrf_delay.h"
 
 #include "nrf_log.h"
 #include "nrf_log_ctrl.h"
@@ -285,6 +287,54 @@ static void idle_state_handle(void)
     }
 }
 
+static void check_write_uicr_serial(void)
+{
+    static const uint32_t serial = 123456;
+    ret_code_t err_code;
+
+    if (NRF_UICR->CUSTOMER[0] == serial)
+    {
+        NRF_LOG_INFO("Serial allready set.");
+    }
+    else
+    {
+        if (NRF_UICR->CUSTOMER[0] == ~0)
+        {
+            // Word is erased (all '1'), so ready to write serial number
+            err_code = sd_softdevice_disable();
+
+            if( err_code == NRF_SUCCESS )
+            {
+                NRF_LOG_INFO("Write to UICR.");
+
+                // Enable write mode.
+                NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
+                while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
+
+                // write value to the register
+                NRF_UICR->CUSTOMER[0] = serial;
+
+                 // Disable flash writing
+                NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
+                while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
+
+                // now reboot the nRF52 - there is no return from this command!
+                NVIC_SystemReset();
+            }
+            else
+            {
+                NRF_LOG_INFO("Failed to disable SoftDevice.");
+            }
+        }
+        else
+        {
+            NRF_LOG_INFO("UICR register contains invalid data (not serial, but not all '1')");
+        }
+    }
+}
+
+
+
 
 /**
  * @brief Function for application main entry.
@@ -297,11 +347,11 @@ int main(void)
     leds_init();
     power_management_init();
     ble_stack_init();
-    advertising_init();
 
     // Start execution.
     NRF_LOG_INFO("Beacon example started.");
-    advertising_start();
+    nrf_delay_ms(100);
+    check_write_uicr_serial();
 
     // Enter main loop.
     for (;; )

[ranger3]

Thanks for your help Einar. It's working now.