Added support for actually controlling the pins via the JSON API

Author: sysprogs

PicoHTTPServer/httpserver.c

@@ -1,3 +1,4 @@
+#include <stdarg.h>
 #include <pico/cyw43_arch.h>
 #include <pico/stdlib.h>
 
@@ -8,6 +9,7 @@
 #include <FreeRTOS.h>
 #include <semphr.h>
 #include <task.h>
+
 #include "debug_printf.h"
 #include "httpserver.h"
 
@@ -25,6 +27,7 @@ struct _http_connection
 {
 	http_server_instance server;
 	int socket;
+	size_t buffered_size;
 	char buffer[1];
 };
 
@@ -364,3 +367,48 @@ void http_server_send_reply(http_connection conn, const char *code, const char *
 	send_all(conn->socket, conn->buffer, done);
 	send_all(conn->socket, content, size);
 }
+
+http_write_handle http_server_begin_write_reply(http_connection conn, const char *code, const char *contentType)
+{
+	conn->buffered_size = snprintf(conn->buffer, conn->server->buffer_size, "HTTP/1.0 %s\r\nContent-Type: %s\r\nConnection: close\r\n\r\n", code, contentType);
+	return (http_write_handle)conn;
+}
+
+void http_server_write_reply(http_write_handle handle, const char *format, ...)
+{
+	http_connection conn = (http_connection)handle;
+	va_list args;
+	va_start(args, format);
+	int written = vsnprintf(conn->buffer + conn->buffered_size, conn->server->buffer_size - conn->buffered_size, format, args);
+	va_end(args);
+	if ((conn->buffered_size + written) < (conn->server->buffer_size - 16))
+	{
+		conn->buffered_size += written;
+		return;
+	}
+	
+	send_all(conn->socket, conn->buffer, conn->buffered_size);
+	va_start(args, format);
+	conn->buffered_size = vsnprintf(conn->buffer, conn->server->buffer_size, format, args);
+	va_end(args);
+}
+
+void http_server_end_write_reply(http_write_handle handle, const char *footer)
+{
+	http_connection conn = (http_connection)handle;
+	int len = footer ? strlen(footer) : 0;
+	if (len && len < (conn->server->buffer_size - conn->buffered_size))
+	{
+		memcpy(conn->buffer + conn->buffered_size, footer, len);
+		conn->buffered_size += len;
+		len = 0;
+	}
+	
+	if (conn->buffered_size)
+		send_all(conn->socket, conn->buffer, conn->buffered_size);
+	
+	if (len)
+		send_all(conn->socket, footer, len);
+	
+	conn->buffered_size = 0;
+}

PicoHTTPServer/httpserver.h

@@ -1,7 +1,7 @@
 #pragma once
 
 typedef struct _http_server_instance *http_server_instance;
-typedef struct _http_connection *http_connection;
+typedef struct _http_connection *http_connection, *http_write_handle;
 
 typedef bool(*http_request_handler)(http_connection conn, char *path, void *context);
 
@@ -18,3 +18,7 @@ typedef struct http_zone
 http_server_instance http_server_create(const char *main_host, const char *main_domain, int max_thread_count, int buffer_size);
 void http_server_add_zone(http_server_instance server, http_zone *instance, const char *prefix, http_request_handler handler, void *context);
 void http_server_send_reply(http_connection conn, const char *code, const char *contentType, const char *content, int size);
+
+http_write_handle http_server_begin_write_reply(http_connection conn, const char *code, const char *contentType);
+void http_server_write_reply(http_write_handle handle, const char *format, ...);
+void http_server_end_write_reply(http_write_handle handle, const char *footer);

PicoHTTPServer/main.c

@@ -53,6 +53,73 @@ static bool do_retrieve_file(http_connection conn, char *path, void *context)
 	return false;
 }
 
+static bool do_handle_api_call(http_connection conn, char *path, void *context)
+{
+	static int s_InitializedMask = 0;
+	
+	if (!strcmp(path, "readpins"))
+	{
+		http_write_handle reply = http_server_begin_write_reply(conn, "200 OK", "text/json");
+		http_server_write_reply(reply, "{\"led0v\": \"%d\"", cyw43_arch_gpio_get(0));
+		
+		int values = gpio_get_all();
+		
+		for (int i = 0; i < 29; i++)
+		{
+			if (i > 22 && i < 26)
+				continue;
+			
+			if (s_InitializedMask & (1 << i))
+				http_server_write_reply(reply, ",\"gpio%dd\": \"%s\",\"gpio%dv\": \"%d\"", i, gpio_get_dir(i) ? "OUT" : "IN", i, (values >> i) & 1);
+		}
+		
+		http_server_end_write_reply(reply, "}");
+		return true;
+	}
+	else if (!memcmp(path, "writepin/", 9))
+	{
+		//e.g. 'writepin/led0?v=1'
+		char *port = path + 9;
+		char *arg = strchr(port, '?');
+		if (arg)
+		{
+			*arg++ = 0;
+			char *value = strchr(arg, '=');
+			*value++ = 0;
+		
+			if (!strcmp(port, "led0"))
+				cyw43_arch_gpio_put(0, value[0] == '1');
+			else if (!memcmp(port, "gpio", 4))
+			{
+				int gpio = atoi(port + 4);
+				if (!(s_InitializedMask & (1 << gpio)))
+				{
+					gpio_init(gpio);
+					s_InitializedMask |= (1 << gpio);
+				}
+
+				if (arg[0] == 'd' && value[0] == 'I')
+				{
+					gpio_set_pulls(gpio, true, false);
+					gpio_set_dir(gpio, GPIO_IN);
+				}
+				else
+				{
+					gpio_set_pulls(gpio, false, false);
+					gpio_set_dir(gpio, GPIO_OUT);
+
+					if (arg[0] == 'v')
+						gpio_put(gpio, value[0] == '1');
+				}
+			}
+			
+			return true;
+		}
+	}
+	
+	return false;
+}
+
 
 static void main_task(__unused void *params)
 {
@@ -83,8 +150,9 @@ static void main_task(__unused void *params)
 	dhcp_server_init(&dhcp_server, &netif->ip_addr, &netif->netmask, settings->domain_name);
 	dns_server_init(netif->ip_addr.addr, settings->secondary_address, settings->hostname, settings->domain_name);
 	http_server_instance server = http_server_create(settings->hostname, settings->domain_name, 4, 4096);
-	static http_zone zone;
-	http_server_add_zone(server, &zone, "", do_retrieve_file, NULL);
+	static http_zone zone1, zone2;
+	http_server_add_zone(server, &zone1, "", do_retrieve_file, NULL);
+	http_server_add_zone(server, &zone2, "/api", do_handle_api_call, NULL);
 	vTaskDelete(NULL);
 }
 
@@ -96,8 +164,8 @@ void debug_printf(const char *format, ...)
 	va_start(args, format);
 	xSemaphoreTake(s_PrintfSemaphore, portMAX_DELAY);
 	vprintf(format, args);
-	xSemaphoreGive(s_PrintfSemaphore);
 	va_end(args);
+	xSemaphoreGive(s_PrintfSemaphore);
 }
 
 void debug_write(const void *data, int size)