Bulk Reads

Bulk reading is the most effective way to optimize your robot’s loop time. In a standard FTC OpMode, every sensor or motor read (like motor.getCurrentPosition()) triggers a separate and slow I2C/Serial communication with the Control or Expansion Hub.

Bulk reads allow you to capture all of the hub’s data (encoder positions, sensor values, etc.) in a single, efficient command.

Setting Up Bulk Reads

To use bulk reads, you need to access the LynxModule (the Rev Hub) in your code.

public void initBulkReads() {
    List<LynxModule> allHubs = hardwareMap.getAll(LynxModule.class);

    for (LynxModule hub : allHubs) {
        hub.setBulkCachingMode(LynxModule.BulkCachingMode.AUTO);
    }
}

The Three Modes

There are three different ways to handle bulk reads in FTC:

1. OFF (Default)

This is the default mode. No bulk reading is performed. Every single sensor or motor read triggers a new communication request with the hub, which is slow.

2. AUTO (Recommended)

This mode automatically performs a bulk read whenever it needs data and clears the cache once per control loop. This is the easiest mode to use and provides a massive speed boost with almost zero effort.

3. MANUAL (Most Accurate)

Manual mode gives the most control. You must manually call hub.clearBulkCache() at the beginning of each loop. This ensures you are always using the latest data and that the cache is handled exactly when you want it.

// At the start of your while(opModeIsActive()) loop:
for (LynxModule hub : allHubs) {
    hub.clearBulkCache();
}

Why This Matters

Without bulk reads, a typical control loop might run at 40-60 Hz. With bulk reads enabled, you can easily reach 100 Hz or even 200 Hz, depending on the complexity of your code. Faster loops lead to more responsive control, especially for PID and odometry.