HealthyPi 5 Vital Signs Monitoring HAT Kit ₹24,995 Add to cart
Legacy firmware. This guide covers the original HealthyPi 5 firmware. For new builds, use the current guide. Go to the equivalent page →

Programming

Zephyr RTOS

Legacy guide — no longer updated

Zephyr is the primary development platform for HealthyPi 5 — all new firmware features land here first. It’s an RTOS designed for resource-constrained devices, with first-class support for the RP2040, real-time scheduling, and a tight build system around west.

If you’re new to embedded development, Arduino is easier to start with. For ongoing work, you want to be on Zephyr.

The workflow at a glance

  1. Install Zephyr + the Zephyr SDK on your machine.
  2. Fetch the HealthyPi 5 firmware workspace.
  3. Build the right firmware variant for your kit.
  4. Flash via UF2 drag-and-drop or via a Raspberry Pi Debug Probe.

1. Install Zephyr and the SDK

Follow the official Zephyr Getting Started guide — there’s no HealthyPi-specific deviation here:

  1. Update your OS and install Zephyr’s host dependencies.
  2. Set up the Zephyr environment + Python dependencies.
  3. Install the Zephyr SDK — this is the toolchain bundle (compiler, linker, etc.) for each supported architecture.

2. Fetch the workspace

Pull the HealthyPi 5 firmware manifest into a fresh Zephyr workspace:

# Initialise the workspace using the HealthyPi 5 manifest
west init -m https://github.com/protocentral/protocentral_healthypi5_zephyr --mr main hpi5-workspace

# Enter the workspace and fetch all the projects in the manifest
cd hpi5-workspace
west update

west update clones Zephyr itself and all the modules referenced in the manifest. Expect a few gigabytes and 5–10 minutes the first time. To confirm it worked:

ls app

You should see source files like main.c and a CMakeLists.txt.

3. Build the firmware

Pick the build that matches your kit and display panel. Each variant has a corresponding make_*.sh script that wraps the same west build command, so you can use either.

Kit / Display west build command Shell script
Basic Kit or Complete Kit + ILI9488 (white) west build -p auto -b healthypi5_rp2040 app -DEXTRA_CONF_FILE='overlay-bt.conf;overlay-display-ili9488.conf;overlay-logger-sd.conf' -DCONFIG_HEALTHYPI_OP_MODE_DISPLAY=n -DEXTRA_DTC_OVERLAY_FILE='healthypi5_rp2040_display_ili9488.overlay;healthypi5_rp2040_sd.overlay' make_basic_ili9488.sh
Basic Kit or Complete Kit + ST7796 (black) west build -p auto -b healthypi5_rp2040 app -DEXTRA_CONF_FILE='overlay-bt.conf;overlay-display-st7796.conf;overlay-logger-sd.conf' -DCONFIG_HEALTHYPI_OP_MODE_DISPLAY=n -DEXTRA_DTC_OVERLAY_FILE='healthypi5_rp2040_display_st7796.overlay;healthypi5_rp2040_sd.overlay' make_basic_st7796.sh
Complete Kit + ILI9488 (white) — Display firmware west build -p auto -b healthypi5_rp2040 app -DEXTRA_CONF_FILE='overlay-bt.conf;overlay-display-ili9488.conf;overlay-logger-sd.conf' -DCONFIG_HEALTHYPI_OP_MODE_DISPLAY=y -DEXTRA_DTC_OVERLAY_FILE='healthypi5_rp2040_display_ili9488.overlay;healthypi5_rp2040_sd.overlay' make_display_ili9488.sh
Complete Kit + ST7796 (black) — Display firmware west build -p auto -b healthypi5_rp2040 app -DEXTRA_CONF_FILE='overlay-bt.conf;overlay-display-st7796.conf,overlay-logger-sd.conf' -DCONFIG_HEALTHYPI_OP_MODE_DISPLAY=y -DEXTRA_DTC_OVERLAY_FILE='healthypi5_rp2040_display_st7796.overlay;healthypi5_rp2040_sd.overlay' make_display_st7796.sh

The build artefact lands in build/zephyr/zephyr.uf2.

4. Flash to the device

Two paths — drag-and-drop is the easier one; the Debug Probe gives you a real flash-and-attach workflow with serial logging.

Option A — drag and drop

Put the HealthyPi 5 into UF2 mode (hold the RP2040 boot button while powering on — see the Welcome page for the full sequence). Drop build/zephyr/zephyr.uf2 onto the RPI-RP2 drive and the device flashes itself.

Option B — Raspberry Pi Debug Probe (OpenOCD)

This is the proper development setup — flashes are atomic, serial logs are visible in the same terminal, and you can attach a debugger.

Install OpenOCD:

macOS 
brew install openocd
Windows
  1. Download OpenOCD for Windows from gnutoolchains.com.
  2. Copy the bin and share folders into C:Program FilesOpenOCD.
  3. Add C:Program FilesOpenOCDbin to your PATH environment variable.

Wire up the Debug Probe:

  1. UART jumper — from the Debug Probe’s UART port to the RP2040 UART connector on HealthyPi 5 (located just below the SpO₂ port).
  2. SWD jumper — from the Debug Probe’s Debug port to the RP2040 Debug connector on HealthyPi 5 (located below the RP2040 port).
  3. Connect the Debug Probe to your host machine via a USB-B cable.

Raspberry Pi Debug Probe wired to HealthyPi 5 RP2040 UART and Debug ports

Flash:

west flash

This builds (if needed), programs the firmware, resets the device, and starts streaming UART logs.

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