ANT: ANT+ Bicycle Power Transmitter

The Bicycle Power Transmitter sample shows the usage of the ANT+ Bicycle Power profile.

Overview

This sample simulates a Bicycle Power Transmitter. The Transmitter application connects to the nearest Bicycle Power Sensor in range and prints out incoming page data. The actual channel state is indicated by the ANT channel state indicator.

On dual core, this sample uses sysbuild to add a network core image to the build by defining the ‘’NRF_DEFAULT_ANT_ONLY’’ with a default value of ‘’y’’ in Kconfig.sysbuild.

Channel configuration

This example uses the default channel configuration:

Parameter

Transmitter

Receiver

Channel type

Master (0x10)

Slave (0x00)

Network key

ANT+

ANT+

RF channel

57 (2457 MHz)

57 (2457 MHz)

Device number

0x31 (49)

0x31 (49)

Device type

0x0B (11)

0x0B (11)

Transmission type

0x05

0x05

Channel period

8182 (4.005 Hz)

8182 (4.005 Hz)

Requirements

Hardware platforms

PCA

Board name

Build target

nRF5340 DK

PCA10095

nrf5340dk/nrf5340

nrf5340dk/nrf5340/cpuapp

nRF52840 DK

PCA10056

nrf52840dk/nrf52840

nrf52840dk/nrf52840

Building and running

This sample can be found under ant/samples/ant_plus/ant_bpwr/bpwr_tx in the nRF Connect SDK folder structure.

You can select how the profile information is modified with the ‘’CONFIG_BSC_TX_MODIFICATION_TYPE’’ value. There are two ways to modify the profile information (instantaneous power):

  • Automatic (‘’UPDATE_AUTO’’), which means that the instantaneous power values rise and fall periodically.

  • Button controlled (‘’UPDATE_MANUAL’’), which means that the data can be modified by pressing the buttons. Pressing Button 1 decreases the instantaneous power. Pressing Button 2 increases the instantaneous power.

You can also select the sensor type with the ‘’CONFIG_SENSOR_TYPE’’ value. There are three types of sensors that change which data is being transmitted (power, wheel torque, and crank torque):

  • Power Sensor (1), which will only transmit power data.

  • Wheel Torque Sensor (2), which will transmit wheel torque data and intermittent power data.

  • Crank Torque Sensor (3), which will transmit crank torque data and intermittent power data.

ANT+ Network Key

This sample selects CONFIG_ANT_KEY_MANAGER to provide access to ant_plus_key_set() (See ANT Key Manager Library). This library function configures the pre-defined ANT+ Network Key for ANT+ devices. Note that network keys, transmission type, device type IDs and RF channels are assigned and regulated to maintain network integrity, and interoperability, except for the default public network.

For more information on Network Keys, visit https://www.thisisant.com/developer/ant-plus/ant-plus-basics/network-keys.

Testing with ANTware II

After programming the sample to your development kit, you can test the Bicycle Power Transmitter using ANTware II:

  1. Compile and program the Bicycle Power Transmitter.

  2. Run ANTware II. Select your ANT PC dongle (for example, ANTUSB-m) from the available devices.

  3. Configure the device channel by loading the channel profile configuration from the following file

    ant\samples\ant_plus\ant_bpwr\bpwr_tx\bpwr_rx_device_profile.xml

    Alternatively, you can configure the device channel manually:

    • Set the channel assignment to Slave.

    • Set the channel ID to “0, 11, 5”.

    • On the Basic tab, set the channel period to 8182 cycles (4.005 Hz) and the radio frequency to 2457 MHz.

    • Keep the default for all other settings.

    Use the Info/Net tab to enter the ANT+ Network Key and select Set Network Key on Net #0.

  4. Click the Auto-Open button. Observe that messages describing the received payload appear for each ANT message. These messages should look similar to the following fragment:

    Received BROADCAST_DATA_0x4E
:: 4e, 00-10-D6-46-26-92-7B-BC-02
Received BROADCAST_DATA_0x4E
:: 4e, 00-10-D7-47-25-58-7E-C6-02
Received BROADCAST_DATA_0x4E
:: 4e, 00-10-D8-48-24-28-81-D0-02
Received BROADCAST_DATA_0x4E
:: 4e, 00-10-D9-49-23-02-84-DA-02
Received BROADCAST_DATA_0x4E

    Each message can be decoded according to the ANT message protocol and the Bicycle Power ANT+ device profile.

Testing the BPWR examples with the ANT+ Simulator tools

You can use the SimulANT+ Bicycle Power Display Simulator to test the BPWR Transmitter. Make sure the Device Number matches the Channel Configuration above (0x31). See the documentation of the ANT+ Simulator tools at thisisant.com for information about how to use these tools.