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Running Pouch Gateway with simulator

Setup

Vanilla Zephyr for nrf52_bsim and native_sim:

west init -m https://github.com/golioth/pouch-gateway.git --mf west-zephyr.yml
west update
west patch apply

Quick switch between Zephyr and NCS:

west config manifest.file west-zephyr.yml && west update && west patch apply
west config manifest.file west-ncs.yml && west update && west patch apply

Build and run

nrf52_bsim with sysbuild

Sysbuild is a generic multi-component build (and flash) infrastructure in Zephyr. In context of nrf52_bsim it is used to build several BabbleSim components. The main component is gateway. Additional sysbuild components are BabbleSim programs:

  • 2.4G PHY implementation (coordinator of the whole simulation)
  • Bluetooth peripherals: either generic samples from zephyr/bluetooth/peripheral* or BLE GATT nodes like pouch/examples/ble_gatt)
  • (optional) BabbleSim handbrake

Default sysbuild configuration builds following:

  • pouch-gateway/gateway (main component)
  • pouch/examples/zephyr/ble_gatt (BLE GATT node)
  • tools/bsim/bin/bs_2G4_phy_v1 (2.4G PHY BabbleSim coordinator)
  • tools/bsim/bin/bs_device_handbrake (BabbleSim handbrake, used to slow down simulation to almost realtime)

Besides building several components sysbuild support flashing all of them sequentially (when talking about hardware), which in most common use case is bootloader followed by application. In case of nrf52_bsim flashing means running. Running BabbleSim components sequentially does not make sense, since all programs need to be run in parallel. That is handled automatically by custom runners implemented in scripts/runners/bsim_*.py, which collect information about simulation and run all programs.

Default example of running gateway with BLE GATT node (and required BabbleSim components) is done with following commands:

west build -p -b nrf52_bsim pouch-gateway/gateway --sysbuild -- \
  -Dperipheral_ble_gatt_example_0_CONFIG_EXAMPLE_DEVICE_ID='"aaaaaaaaaaaaaaaaaaaaaaaa"'
west flash

It is possible to include more BLE GATT nodes in simulation. Example of running 2 nodes:

west build -p -b nrf52_bsim pouch-gateway/gateway --sysbuild -- \
  -DSB_CONFIG_PERIPHERAL_BLE_GATT_EXAMPLE_NUM=2 \
  -Dperipheral_ble_gatt_example_0_CONFIG_POUCH_DEVICE_ID='"aaaaaaaaaaaaaaaaaaaaaaaa"' \
  -Dperipheral_ble_gatt_example_1_CONFIG_POUCH_DEVICE_ID='"bbbbbbbbbbbbbbbbbbbbbbbb"'
west flash

It is even possible to include other non-BLE GATT nodes. So far there is support for vanilla Zephyr peripheral sample zephyr/samples/bluetooth/peripheral:

west build -p -b nrf52_bsim pouch-gateway/gateway --sysbuild -- \
  -DSB_CONFIG_PERIPHERAL_ZEPHYR=y \
  -Dperipheral_ble_gatt_example_0_CONFIG_POUCH_DEVICE_ID='"aaaaaaaaaaaaaaaaaaaaaaaa"'
west flash

native_sim with USB Bluetooth dongle

It is possible to communicate with real (physical) Bluetooth devices, while still maintaining almost all benefits of native_sim platform, such as development speed, host debugging capabilities, infinite resources, etc. This is achieved by Bluetooth HCI (Host Controller Interface), which can be implemented on various transport layers (UART, SPI, USB, Linux kernel HCI, ...).

When building native_sim with Bluetooth support on Linux both UART and Linux kernel HCI transports are supported. Both work almost the same, since they operate on stream of data. See native_sim in Zephyr for details.

Recommended setup for testing is nRF52840 Dongle with Bluetooth controller available through HCI UART. The main advantage is that controller will run the same firmware (Zephyr HCI UART) as gateway running on physical devices like nRF9160-DK (there is even the same nRF52840 Bluetooth Controller chip) or Thingy:91 X (which contains slightly more powerful nRF5340 as Bluetooth Controller).

Build Bluetooth Controller firmware with HCI UART over USB CDC-ACM for nRF52840 Dongle:

west build -p -b nrf52840dongle/nrf52840 zephyr/samples/bluetooth/hci_uart

See Programming and Debugging page on how to flash that on the dongle.

After connecting this dongle to host PC it is not required to connect that to native_sim. First setup a proxy using socat so it will be possible to access HCI UART data stream over TCP (port 12345 is used as example):

while :; do socat -x -dd /dev/serial/by-id/usb-ZEPHYR_Zephyr_HCI_UART_sample_98AE46C3F73B765A-if00,rawer,b115200 tcp-listen:12345,reuseaddr; done

then run native_sim with following command:

build/zephyr/zephyr.exe -bt-dev=127.0.0.1:12345

At this stage native_sim will connect to cloud using native networking (via Native Simulator Offloaded Sockets) and still be able to find local Bluetooth devices, communicate with them and send requested pouches.