Understanding Unexpected Power Consumption in CC1310F128RHBR

Analyzing Unexpected Power Consumption in CC1310F128RHBR

Introduction

The CC1310F128RHBR is a popular low-power wireless microcontroller used for a variety of IoT applications. However, users might experience unexpected power consumption that can impact the battery life and efficiency of their designs. This article will help you understand the common reasons behind this issue, where the fault might lie, and provide step-by-step solutions to troubleshoot and fix the problem.

Common Causes of Unexpected Power Consumption

Several factors can contribute to unexpected power consumption in the CC1310F128RHBR. Let's break down the most common ones:

Incorrect Low Power Mode Configuration: The CC1310F128RHBR has several low-power modes, including Standby Mode and Shutdown Mode. If these modes are not correctly configured, the device might consume more power than expected. Fault: The device stays in a higher power mode (e.g., Active Mode) longer than necessary. Peripherals Not Disabled: Some peripherals on the microcontroller (e.g., UART, SPI, ADC, etc.) can continue drawing power if they are not properly disabled when not in use. Fault: Peripherals continue to run in the background, leading to unnecessary power consumption. Improper Clock Configuration: The CC1310 has an internal low-frequency oscillator (LFXT) and high-frequency oscillator (HFXT). Using the high-frequency oscillator when the low-frequency one would suffice can increase power consumption. Fault: The high-frequency clock source is active when a lower frequency is enough for the application. Software Bugs: If the software is incorrectly configured, such as in cases where there is an endless loop or some task that keeps the device active, it could result in high power usage. Fault: The device is stuck in an active state due to software issues, causing high power drain. Radio Transmissions: The radio is one of the most power-hungry components of the CC1310. If the radio is left on too long or the power levels are too high for a specific application, power consumption can spike. Fault: The radio is transmitting or listening for signals when it’s not necessary. Troubleshooting and Fixing Unexpected Power Consumption

Here’s a detailed, step-by-step process to address the unexpected power consumption issue:

1. Check Power Mode Configuration

Step 1.1: Review your power management configuration to ensure the device is entering low-power modes when not in use. For example:

Standby Mode should be used when you don’t need to process or communicate.

Shutdown Mode is the deepest power-saving state when the device is idle for long periods.

Step 1.2: Verify the code that configures the power mode. Make sure there are no calls that inadvertently prevent the device from entering these modes. For example:

Power_setConstraint(PowerCC26XX_CC13XX_SHUTDOWN); Step 1.3: Use a power profiler tool (e.g., the Power Measurement Tool) to track the power consumption in different modes and adjust your configuration as necessary.

2. Disable Unused Peripherals

Step 2.1: Go through your peripherals and confirm that each one is properly disabled when not needed. For instance:

Disable ADC if it's not taking measurements.

Turn off UART or SPI interface s if they are idle.

Step 2.2: Ensure that all unused peripherals are powered down in the software. Example for turning off a peripheral like UART:

UART_close(handle); Step 2.3: Review the pin configuration, as some pins might be configured as input or output unnecessarily. Unused pins should be placed in a low-power state.

3. Verify Clock Settings

Step 3.1: Examine the clock settings in your project. If you're using a higher frequency clock than necessary, it could lead to higher power consumption. For low-power modes, the low-frequency crystal oscillator (LFXT) should generally be used.

Step 3.2: Ensure that the HFXT (high-frequency oscillator) is turned off when not required:

// Disable HFXT if not required SysCtrl_SetLdoMode(SysCtrl_LdoMode_STANDARD); Step 3.3: Make sure that the clock source is chosen optimally for your application's needs. You can refer to the CC1310 datasheet for clock configurations and their power implications.

4. Check Software for Bugs

Step 4.1: Review your application code for infinite loops or tasks that prevent the device from entering low-power states.

Look for any logic errors or incorrect interrupt handling.

Step 4.2: Implement a watchdog timer to ensure that the system resets if something goes wrong. This prevents the device from staying stuck in an active state indefinitely.

Watchdog_clear(WATCHDOG0); Step 4.3: Use debug tools to trace the execution and check where the device might be consuming more power than expected.

5. Control Radio Power Consumption

Step 5.1: Review the radio settings and ensure it isn’t left in a transmission mode longer than necessary.

Step 5.2: Implement Radio Duty Cycling (RDC), where the radio sleeps for a portion of the time to save power. For example:

RF _cmdPropRx.rxConf.bAutoFlushIgnored = 1; RF_runCmd(handle, (RF_Cmd*) &RF_cmdPropRx, RF_PriorityNormal, NULL, 0); Step 5.3: Control the radio transmit power. If the application doesn’t need maximum range, reduce the transmit power: RF_cmdPropTx.txPower = TX_POWER_MEDIUM;

6. Use the CC1310 Power Profiler

Step 6.1: Utilize the CC1310 Power Profiler tool, which can help monitor the device’s current consumption in real-time. It provides insight into which mode the device is in and identifies areas that could be optimized for power savings.

Step 6.2: Set up periodic measurements of the current and ensure that the device switches into a low-power state when idle.

Conclusion

Unexpected power consumption in the CC1310F128RHBR is often the result of misconfigured power settings, unused peripherals, improper clock settings, or software issues. By following the outlined troubleshooting steps and using the power profiler, you can identify the cause of the problem and implement a solution. Ensuring the device enters low-power modes when possible, disabling unused peripherals, optimizing clock settings, and reducing unnecessary radio usage will lead to better power efficiency and longer battery life for your application.