samples: cert-provsioning: add nRF52840

Add board files and documentation to support nRF52840dk in this sample.

Signed-off-by: Mike Szczys <[email protected]>

samples/certificate_provisioning/README.rst

@@ -48,6 +48,60 @@ sample application (i.e. ``samples/certificate_provisioning``) and type:
 
 See `ESP32`_ for details on how to use ESP32 board.
 
+nRF52840 DK + ESP32-WROOM-32
+----------------------------
+
+This subsection documents using nRF52840 DK running Zephyr with offloaded ESP-AT
+WiFi driver and ESP32-WROOM-32 module based board (such as ESP32 DevkitC rev.
+4) running WiFi stack. See `AT Binary Lists`_ for links to ESP-AT binaries and
+details on how to flash ESP-AT image on ESP chip. Flash ESP chip with following
+command:
+
+.. code-block:: console
+
+   esptool.py write_flash --verify 0x0 PATH_TO_ESP_AT/factory/factory_WROOM-32.bin
+
+Connect nRF52840 DK and ESP32-DevKitC V4 (or other ESP32-WROOM-32 based board)
+using wires:
+
++-----------+--------------+
+|nRF52840 DK|ESP32-WROOM-32|
+|           |              |
++-----------+--------------+
+|P1.01 (RX) |IO17 (TX)     |
++-----------+--------------+
+|P1.02 (TX) |IO16 (RX)     |
++-----------+--------------+
+|P1.03 (CTS)|IO14 (RTS)    |
++-----------+--------------+
+|P1.04 (RTS)|IO15 (CTS)    |
++-----------+--------------+
+|P1.05      |EN            |
++-----------+--------------+
+|GND        |GND           |
++-----------+--------------+
+
+Configure the following Kconfig options based on your WiFi AP credentials:
+
+- GOLIOTH_SAMPLE_WIFI_SSID - WiFi SSID
+- GOLIOTH_SAMPLE_WIFI_PSK  - WiFi PSK
+
+by adding these lines to configuration file (e.g. ``prj.conf`` or
+``board/nrf52840dk_nrf52840.conf``):
+
+.. code-block:: cfg
+
+   CONFIG_GOLIOTH_SAMPLE_WIFI_SSID="my-wifi"
+   CONFIG_GOLIOTH_SAMPLE_WIFI_PSK="my-psk"
+
+On your host computer open a terminal window, locate the source code of this
+sample application (i.e., ``samples/certificate_provisioning``) and type:
+
+.. code-block:: console
+
+   $ west build -b nrf52840dk_nrf52840 samples/certificate_provisioning
+   $ west flash
+
 nRF9160 DK
 ----------
 

samples/certificate_provisioning/boards/nrf52840dk_nrf52840.conf

@@ -0,0 +1,18 @@
+# WiFi
+CONFIG_WIFI=y
+CONFIG_WIFI_ESP_AT=y
+CONFIG_WIFI_ESP_AT_MDM_RX_BUF_COUNT=40
+
+CONFIG_NET_L2_WIFI_SHELL=y
+CONFIG_GOLIOTH_SAMPLE_WIFI=y
+
+# General config
+CONFIG_HEAP_MEM_POOL_SIZE=4096
+
+# MCU Manager
+CONFIG_MCUBOOT_BOOTUTIL_LIB=y
+CONFIG_MCUMGR_MGMT_NOTIFICATION_HOOKS=y
+CONFIG_MCUMGR_GRP_FS_FILE_ACCESS_HOOK=y
+
+# Allow reboot from shell after loading certificates
+CONFIG_REBOOT=y

samples/certificate_provisioning/boards/nrf52840dk_nrf52840.overlay

@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2021 Golioth, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&uart1_default {
+	cts-rts {
+		psels = <NRF_PSEL(UART_CTS, 1, 3)>,
+			<NRF_PSEL(UART_RTS, 1, 4)>;
+	};
+};
+
+&uart1_sleep {
+	cts-rts {
+		psels = <NRF_PSEL(UART_CTS, 1, 3)>,
+			<NRF_PSEL(UART_RTS, 1, 4)>;
+		low-power-enable;
+	};
+};
+
+&uart1 {
+	status = "okay";
+	hw-flow-control;
+
+	esp_wifi: esp-wifi {
+		compatible = "espressif,esp-at";
+		power-gpios = <&gpio1 5 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
+		status = "okay";
+	};
+};