From 4300a565fbf639cb800eab813ee2a3a07f4f22a2 Mon Sep 17 00:00:00 2001
From: Waldemar Schmidt <waldemar.schmidt2@haw-hamburg.de>
Date: Mon, 4 Apr 2022 14:43:39 +0200
Subject: [PATCH] Add sensor CoAP resources
---
08-coap-basic/server.c | 82 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 81 insertions(+), 1 deletion(-)
diff --git a/08-coap-basic/server.c b/08-coap-basic/server.c
index 6a9e01c..5c23d6a 100644
--- a/08-coap-basic/server.c
+++ b/08-coap-basic/server.c
@@ -24,13 +24,20 @@
static ssize_t _riot_board_handler(coap_pkt_t* pdu, uint8_t *buf, size_t len, void *ctx);
/* [TASK 2: add the prototype of your resource handler here] */
+static ssize_t _led_handler(coap_pkt_t *pdu, uint8_t *buf, size_t len, void *ctx);
/* [TASK 2: declare the array of LEDs here] */
+static const gpio_t leds[] = {
+ LED0_PIN,
+ LED1_PIN,
+ LED2_PIN,
+};
/* CoAP resources. Must be sorted by path (ASCII order). */
static const coap_resource_t _resources[] = {
/* [TASK 2: register your CoAP resource here] */
- { "/riot/board", COAP_GET, _riot_board_handler, NULL },
+ { "/led/", COAP_GET | COAP_PUT | COAP_MATCH_SUBTREE, _led_handler, NULL },
+ { "/riot/board", COAP_GET, _riot_board_handler, NULL }
};
/* a gcoap listener is a collection of resources. Additionally we can specify
@@ -53,9 +60,82 @@ void server_init(void)
gcoap_register_listener(&_listener);
/* [TASK 2: initialize the GPIOs here] */
+ for (unsigned i = 0; i < ARRAY_SIZE(leds); i++) {
+ gpio_init(leds[i], GPIO_OUT);
+ gpio_set(leds[i]);
+}
}
/* [TASK 2: implement the LED handler here] */
+static ssize_t _led_handler(coap_pkt_t *pdu, uint8_t *buf, size_t len, void *ctx)
+{
+ (void) ctx; /* argument not used */
+
+ /* implement your handler here */
+
+ char uri[CONFIG_NANOCOAP_URI_MAX] = { 0 };
+ /* get the request path, to know which LED is being requested */
+ if (coap_get_uri_path(pdu, (uint8_t *)uri) <= 0) {
+ /* reply with an error if we could not parse the URI */
+ return gcoap_response(pdu, buf, len, COAP_CODE_BAD_REQUEST);
+ }
+
+ /* find the LED number, the URI should be /led/<number> */
+ char *led_str = uri + strlen("/led/");
+ unsigned led_number = atoi(led_str);
+
+ /* verify that the number is valid, respond with an error otherwise */
+ if (led_number >= ARRAY_SIZE(leds)) {
+ return gcoap_response(pdu, buf, len, COAP_CODE_BAD_REQUEST);
+ }
+
+
+ ssize_t resp_len = 0;
+ int led_status = 0;
+ unsigned method = coap_method2flag(coap_get_code_detail(pdu));
+
+ switch (method) {
+ case COAP_PUT: /* on PUT, we set the status of the LED based on the payload */
+ /* check if there is a payload with a LED status */
+ if (pdu->payload_len) {
+ led_status = atoi((char *)pdu->payload);
+ } else {
+ return gcoap_response(pdu, buf, len, COAP_CODE_BAD_REQUEST);
+ }
+
+ if (led_status) {
+ gpio_clear(leds[led_number]);
+ } else {
+ gpio_set(leds[led_number]);
+ }
+ return gcoap_response(pdu, buf, len, COAP_CODE_CHANGED);
+
+ case COAP_GET: /* on GET, we return the status of the LED in plain text */
+ /* initialize the CoAP response */
+ gcoap_resp_init(pdu, buf, len, COAP_CODE_CONTENT);
+
+ /* set the content format to plain text */
+ coap_opt_add_format(pdu, COAP_FORMAT_TEXT);
+
+ /* finish the options indicating that we will include a payload */
+ resp_len = coap_opt_finish(pdu, COAP_OPT_FINISH_PAYLOAD);
+
+ /* get the current status of the LED, which is the inverted value of the GPIO */
+ led_status = !gpio_read(leds[led_number]);
+
+ /* based on the status, write the value of the payload to send */
+ if (led_status) {
+ pdu->payload[0] = '1';
+ } else {
+ pdu->payload[0] = '0';
+ }
+ resp_len++;
+ return resp_len;
+ }
+
+
+ return 0;
+}
/*
* Server callback for /riot/board. Accepts only GET.