Merge branch 'develop' into patch-3

Author: kilograham

README.md

@@ -1,18 +1,21 @@
 # Raspberry Pi Pico SDK Examples
 
-By default, the Pico SDK targets builds for RP2040 (PICO_PLATFORM=rp2040). To build for RP2350 instead, pass
-`-DPICO_PLATFORM=rp2350` to CMake (or `-DPICO_PLATFORM=rp2350-riscv` for RISC-V). Alternatively, in many cases, you can rely
-on the board configuration to set the platform for you. For example, passing `-DPICO_BOARD=pico2` will automatically select RP2350.
+## Getting started
 
-Most, but not all examples, currently work on RP2350 however you should be able to do a full build with any of the above platforms (PICO_PLATFORM=host however currently fails on some examples)
+See [Getting Started with the Raspberry Pi Pico](https://rptl.io/pico-get-started) and the README in the [pico-sdk](https://github.com/raspberrypi/pico-sdk) for information
+on getting up and running.
 
-For RISC-V compilation, you should take a compiler from here: https://www.embecosm.com/resources/tool-chain-downloads/#riscv-stable
+##### Notes on different boards and platforms (RP2040 / RP2350) 
 
+The majority of examples are applicable to both RP2040 and RP2350 based boards,
+however certain examples that use chip-specific functionality will only build on that platform.
+Similarly, Wi-Fi and Bluetooth examples will only build on a board that includes Wi-Fi and Bluetooth support.
 
-## Getting started
+Platform and board information are passed to the CMake build via the `PICO_PLATFORM` and `PICO_BOARD` variables.
+For more information see the "Platform and Board Configuration" chapter of 
+the [Raspberry Pi Pico-series C/C++ SDK](https://rptl.io/pico-c-sdk) book
 
-See [Getting Started with the Raspberry Pi Pico](https://rptl.io/pico-get-started) and the README in the [pico-sdk](https://github.com/raspberrypi/pico-sdk) for information
-on getting up and running.
+Information on which examples are not being built is output during the CMake configuration step.
 
 ### First Examples
 
@@ -187,6 +190,7 @@ App|Description
 [picow_httpd](pico_w/wifi/httpd) | Runs a LWIP HTTP server test app
 [picow_http_client](pico_w/wifi/http_client) | Demonstrates how to make http and https requests
 [picow_http_client_verify](pico_w/wifi/http_client) | Demonstrates how to make a https request with server authentication
+[picow_mqtt_client](pico_w/wifi/mqtt) | Demonstrates how to implement an MQTT client application
 
 #### FreeRTOS examples
 
@@ -426,6 +430,14 @@ App|Description
 ---|---
 [dev_lowlevel](usb/device/dev_lowlevel) | A USB Bulk loopback implemented with direct access to the USB hardware (no TinyUSB)
 
+#### Custom CDC with SDK stdio
+
+This example demonstrates how to use the TinyUSB CDC device library to create two USB serial ports, and assign one of them to the SDK for stdio.
+
+App|Description
+---|---
+[dev_cdc](usb/device/dev_cdc) | A USB CDC device example with two serial ports, one of which is used for stdio. The example exposes two serial ports over USB to the host. The first port is used for stdio, and the second port is used for a simple echo loopback. You can connect to the second port and send some characters, and they will be echoed back on the first port while you will receive a "OK\r\n" message on the second port indicating that the data was received.
+
 ### USB Host
 
 All the USB host examples come directly from the TinyUSB host examples directory [here](https://github.com/hathach/tinyusb/tree/master/examples/host).

blink_simple/blink_simple.c

@@ -10,6 +10,10 @@
 #define LED_DELAY_MS 250
 #endif
 
+#ifndef PICO_DEFAULT_LED_PIN
+#warning blink_simple example requires a board with a regular LED
+#endif
+
 // Initialize the GPIO for the LED
 void pico_led_init(void) {
 #ifdef PICO_DEFAULT_LED_PIN

i2c/lis3dh_i2c/lis3dh_i2c.c

@@ -27,7 +27,7 @@
 const int ADDRESS = 0x18;
 const uint8_t CTRL_REG_1 = 0x20;
 const uint8_t CTRL_REG_4 = 0x23;
-const uint8_t TEMP_CFG_REG = 0xC0;
+const uint8_t TEMP_CFG_REG = 0x1F;
 
 #ifdef i2c_default
 

interp/hello_interp/hello_interp.c

@@ -215,7 +215,7 @@ void texture_mapping_setup(uint8_t *texture, uint texture_width_bits, uint textu
                            uint uv_fractional_bits) {
     interp_config cfg = interp_default_config();
     // set add_raw flag to use raw (un-shifted and un-masked) lane accumulator value when adding
-    // it to the the lane base to make the lane result
+    // it to the lane base to make the lane result
     interp_config_set_add_raw(&cfg, true);
     interp_config_set_shift(&cfg, uv_fractional_bits);
     interp_config_set_mask(&cfg, 0, texture_width_bits - 1);
@@ -288,4 +288,4 @@ int main() {
     texture_mapping();
 
     return 0;
-}
+}

multicore/multicore_runner/multicore_runner.c

@@ -12,15 +12,17 @@
 
 #define FLAG_VALUE 123
 
+typedef int32_t (*func_ptr_t)(int32_t);
+
 void core1_entry() {
     while (1) {
         // Function pointer is passed to us via the FIFO
         // We have one incoming int32_t as a parameter, and will provide an
         // int32_t return value by simply pushing it back on the FIFO
         // which also indicates the result is ready.
-        int32_t (*func)() = (int32_t(*)()) multicore_fifo_pop_blocking();
+        func_ptr_t func = (func_ptr_t) multicore_fifo_pop_blocking();
         int32_t p = multicore_fifo_pop_blocking();
-        int32_t result = (*func)(p);
+        int32_t result = func(p);
         multicore_fifo_push_blocking(result);
     }
 }

pico_w/wifi/CMakeLists.txt

@@ -18,6 +18,7 @@ else()
     add_subdirectory_exclude_platforms(tcp_server)
     add_subdirectory_exclude_platforms(udp_beacon)
     add_subdirectory_exclude_platforms(http_client)
+    add_subdirectory_exclude_platforms(mqtt)
 
     if (NOT PICO_MBEDTLS_PATH)
         message("Skipping tls examples as PICO_MBEDTLS_PATH is not defined")

pico_w/wifi/access_point/picow_access_point.c

@@ -306,9 +306,17 @@ int main() {
 
     cyw43_arch_enable_ap_mode(ap_name, password, CYW43_AUTH_WPA2_AES_PSK);
 
+    #if LWIP_IPV6
+    #define IP(x) ((x).u_addr.ip4)
+    #else
+    #define IP(x) (x)
+    #endif
+
     ip4_addr_t mask;
-    IP4_ADDR(ip_2_ip4(&state->gw), 192, 168, 4, 1);
-    IP4_ADDR(ip_2_ip4(&mask), 255, 255, 255, 0);
+    IP(state->gw).addr = PP_HTONL(CYW43_DEFAULT_IP_AP_ADDRESS);
+    IP(mask).addr = PP_HTONL(CYW43_DEFAULT_IP_MASK);
+
+    #undef IP
 
     // Start the dhcp server
     dhcp_server_t dhcp_server;

pico_w/wifi/lwipopts_examples_common.h

@@ -20,7 +20,9 @@
 #define MEM_LIBC_MALLOC             0
 #endif
 #define MEM_ALIGNMENT               4
+#ifndef MEM_SIZE
 #define MEM_SIZE                    4000
+#endif
 #define MEMP_NUM_TCP_SEG            32
 #define MEMP_NUM_ARP_QUEUE          10
 #define PBUF_POOL_SIZE              24

pico_w/wifi/mbedtls_config_examples_common.h

@@ -68,4 +68,7 @@
 #define MBEDTLS_PEM_PARSE_C
 #define MBEDTLS_BASE64_C
 
-#endif
+// The following significantly speeds up mbedtls due to NIST optimizations.
+#define MBEDTLS_ECP_NIST_OPTIM
+
+#endif

pico_w/wifi/mqtt/CMakeLists.txt

@@ -0,0 +1,79 @@
+# Define the host name of the MQTT server in an environment variable or pass it to cmake,
+# e.g. cmake -DMQTT_SERVER=myserver ..
+
+if (DEFINED ENV{MQTT_SERVER} AND (NOT MQTT_SERVER))
+    set(MQTT_SERVER $ENV{MQTT_SERVER})
+    message("Using MQTT_SERVER from environment ('${MQTT_SERVER}')")
+endif()
+if (NOT MQTT_SERVER)
+    message("Skipping MQTT example as MQTT_SERVER is not defined")
+    return()
+endif()
+# Define the name of an MQTT broker/server to enable this example
+set(MQTT_SERVER "${MQTT_SERVER}" CACHE INTERNAL "MQTT server for examples")
+
+if (DEFINED ENV{MQTT_USERNAME} AND (NOT MQTT_USERNAME))
+    set(MQTT_USERNAME $ENV{MQTT_USERNAME})
+    message("Using MQTT_USERNAME from environment ('${MQTT_USERNAME}')")
+endif()
+set(MQTT_USERNAME "${MQTT_USERNAME}" CACHE INTERNAL "MQTT user name for examples")
+if (DEFINED ENV{MQTT_PASSWORD} AND (NOT MQTT_PASSWORD))
+    set(MQTT_PASSWORD $ENV{MQTT_PASSWORD})
+    message("Using MQTT_PASSWORD from environment")
+endif()
+set(MQTT_PASSWORD "${MQTT_PASSWORD}" CACHE INTERNAL "MQTT password for examples")
+
+# Set path to the certificate include file
+if (NOT MQTT_CERT_PATH)
+    set(MQTT_CERT_PATH ${CMAKE_CURRENT_LIST_DIR}/certs/${MQTT_SERVER})
+endif()
+
+# Set the name of the certificate include file
+if (NOT MQTT_CERT_INC)
+    set(MQTT_CERT_INC mqtt_client.inc)
+endif()
+
+set(TARGET_NAME picow_mqtt_client)
+add_executable(${TARGET_NAME}
+    mqtt_client.c
+    )
+target_link_libraries(${TARGET_NAME}
+    pico_stdlib
+    hardware_adc
+    pico_cyw43_arch_lwip_threadsafe_background
+    pico_lwip_mqtt
+    pico_mbedtls
+    pico_lwip_mbedtls
+    )
+target_include_directories(${TARGET_NAME} PRIVATE
+    ${CMAKE_CURRENT_LIST_DIR}
+    ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts or any other standard includes, if required
+    )
+target_compile_definitions(${TARGET_NAME} PRIVATE
+    WIFI_SSID=\"${WIFI_SSID}\"
+    WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
+    MQTT_SERVER=\"${MQTT_SERVER}\"
+    )
+if (EXISTS "${MQTT_CERT_PATH}/${MQTT_CERT_INC}")
+    target_compile_definitions(${TARGET_NAME} PRIVATE
+        MQTT_CERT_INC=\"${MQTT_CERT_INC}\" # contains the tls certificates for MQTT_SERVER needed by the client
+        ALTCP_MBEDTLS_AUTHMODE=MBEDTLS_SSL_VERIFY_REQUIRED
+        )
+    target_include_directories(${TARGET_NAME} PRIVATE
+        ${MQTT_CERT_PATH}
+        )
+endif()
+if (MQTT_USERNAME AND MQTT_PASSWORD)
+    target_compile_definitions(${TARGET_NAME} PRIVATE
+        MQTT_USERNAME=\"${MQTT_USERNAME}\"
+        MQTT_PASSWORD=\"${MQTT_PASSWORD}\"
+    )
+endif()
+pico_add_extra_outputs(${TARGET_NAME})
+
+# Ignore warnings from lwip code
+set_source_files_properties(
+    ${PICO_LWIP_PATH}/src/apps/altcp_tls/altcp_tls_mbedtls.c
+    PROPERTIES
+    COMPILE_OPTIONS "-Wno-unused-result"
+    )