UICR-NRF52-READ-and-WRITE

This firmware is designed for the nRF52-DK and demonstrates how to store factory calibration data in the UICR (User Information Configuration Registers). The system utilizes a button press to trigger the write operation, and the stored data can be verified using external tools such as nrfjprog.

Features

• Initialization Sequence: Upon startup, all four LEDs on the nRF52-DK blink twice as a greeting.
• Button-Triggered UICR Write:
  • Pressing Button 1 writes a 32-bit calibration value to the CUSTOMER[0] memory location (0x10001080) in the UICR.
  • The write operation includes:
    • Temperature offset.
    • Temperature setpoint.
    • Operation mode.
    • Sensor status.
  • The firmware writes the data in a pre-concatenated 32-bit format.
• Debouncing Logic: Ensures button presses are properly debounced to avoid multiple triggers during a single press.
• System Reset: After successfully writing to the UICR, the system automatically resets to apply the new configuration.

UICR Overview

The UICR (User Information Configuration Registers) is a dedicated memory area in the nRF52 SoC that allows non-volatile storage of factory calibration data or other user-specific parameters. This firmware utilizes the CUSTOMER[0] section located at 0x10001080.

32-Bit Data Structure

The stored data is organized as follows:

Bits	Field	Description
0–7	Temperature Offset	Offset in °C (8-bit signed integer).
8–9	Reserved	Reserved for future use.
10–11	Operation Mode	Operation mode (2-bit).
12–13	Sensor Status	Sensor status (2-bit).
14–23	Temperature Setpoint	Setpoint in 0.1 °C units (10-bit).
24–31	Reserved	Reserved for future use.

Example Data

For example, if the following values are written:

• Offset Temperature: 10°C
• Setpoint Temperature: 750 (represents 75.0 °C)
• Mode: 1
• Status: 0

The 32-bit data stored in 0x10001080 would be: 0x00BB840A.

Usage Instructions

Hardware Setup

1. Connect the nRF52-DK to your PC via USB.
2. Ensure that Button 1 and LED 1–4 are functional.

Firmware Behavior

1. On power-up or reset, the LEDs blink twice as a startup greeting.
2. Press Button 1 to trigger the write operation to the UICR.
3. Upon successful write, the device resets automatically.

Verification

Use the nrfjprog tool to verify the written data:

nrfjprog --memrd 0x10001080 --n 4

Expected Output:
0x10001080: 00BB840A                              |....|