Files
espresso_frame/firmware/main/frame_client.c
T

323 lines
12 KiB
C

#include <string.h>
#include "esp_event.h"
#include "esp_log.h"
#include "esp_wifi.h"
#include "esp_wifi_default.h"
#include "esp_netif.h"
#include "esp_http_client.h"
#include "esp_sleep.h"
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "epd7in3e.h"
#include "status_screen.h"
#include "frame_client.h"
static const char *TAG = "frame_client";
#define STA_CONNECTED_BIT BIT0
#define STA_FAILED_BIT BIT1
static EventGroupHandle_t s_sta_event_group;
/* wifi_sta_config_t's ssid/password fields are fixed-size byte arrays, not
* necessarily null-terminated (a full 32-char SSID fills the field exactly).
* snprintf() flags that as a possible truncation at -Werror, so copy by
* hand instead. */
static void copy_wifi_field(uint8_t *dst, size_t dst_size, const char *src)
{
size_t len = strnlen(src, dst_size);
memcpy(dst, src, len);
if (len < dst_size) {
dst[len] = '\0';
}
}
static void sta_event_handler(void *arg, esp_event_base_t event_base,
int32_t event_id, void *event_data)
{
if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
esp_wifi_connect();
} else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
ESP_LOGW(TAG, "Disconnected from home WiFi");
xEventGroupSetBits(s_sta_event_group, STA_FAILED_BIT);
} else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
ip_event_got_ip_t *event = (ip_event_got_ip_t *)event_data;
ESP_LOGI(TAG, "Got IP: " IPSTR, IP2STR(&event->ip_info.ip));
xEventGroupSetBits(s_sta_event_group, STA_CONNECTED_BIT);
}
}
esp_err_t frame_wifi_connect_sta(const frame_config_t *cfg)
{
s_sta_event_group = xEventGroupCreate();
esp_netif_t *sta_netif = esp_netif_create_default_wifi_sta();
wifi_init_config_t init_cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK(esp_wifi_init(&init_cfg));
esp_event_handler_instance_t wifi_handler;
esp_event_handler_instance_t ip_handler;
ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &sta_event_handler, NULL, &wifi_handler));
ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &sta_event_handler, NULL, &ip_handler));
wifi_config_t wifi_config = {0};
copy_wifi_field(wifi_config.sta.ssid, sizeof(wifi_config.sta.ssid), cfg->sta_ssid);
copy_wifi_field(wifi_config.sta.password, sizeof(wifi_config.sta.password), cfg->sta_password);
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));
ESP_ERROR_CHECK(esp_wifi_start());
esp_err_t result = ESP_FAIL;
for (int attempt = 1; attempt <= CONFIG_FRAME_STA_CONNECT_MAX_RETRIES; attempt++) {
ESP_LOGI(TAG, "Connecting to '%s' (attempt %d/%d)", cfg->sta_ssid, attempt,
CONFIG_FRAME_STA_CONNECT_MAX_RETRIES);
xEventGroupClearBits(s_sta_event_group, STA_CONNECTED_BIT | STA_FAILED_BIT);
esp_wifi_connect();
EventBits_t bits = xEventGroupWaitBits(s_sta_event_group, STA_CONNECTED_BIT | STA_FAILED_BIT,
pdTRUE, pdFALSE,
pdMS_TO_TICKS(CONFIG_FRAME_STA_CONNECT_TIMEOUT_MS));
if (bits & STA_CONNECTED_BIT) {
result = ESP_OK;
break;
}
ESP_LOGW(TAG, "Attempt %d/%d failed", attempt, CONFIG_FRAME_STA_CONNECT_MAX_RETRIES);
}
esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, wifi_handler);
esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, ip_handler);
vEventGroupDelete(s_sta_event_group);
s_sta_event_group = NULL;
if (result != ESP_OK) {
/* Fully tear the WiFi driver back down on failure -- the caller
* falls back to provisioning, which calls esp_wifi_init() again
* for AP mode. Leaving the driver merely stopped (rather than
* deinitialized) made that second esp_wifi_init() call fail with
* ESP_ERR_INVALID_STATE and abort, confirmed on hardware. */
esp_wifi_stop();
esp_wifi_deinit();
esp_netif_destroy_default_wifi(sta_netif);
}
return result;
}
typedef struct {
bool reachable;
uint32_t refresh_interval_s; /* CONFIG_FRAME_SLEEP_INTERVAL_S if absent/unparseable */
} frame_server_config_t;
/* Finds the first integer value associated with "key" in a small JSON
* blob, e.g. 3600 in {"refresh_interval_s": 3600}. Not a general JSON
* parser -- just enough for this project's small, flat config response,
* to avoid pulling in a JSON library for one scalar field. */
static bool json_extract_uint(const char *json, const char *key, uint32_t *out)
{
char needle[48];
snprintf(needle, sizeof(needle), "\"%s\"", key);
const char *pos = strstr(json, needle);
if (pos == NULL) {
return false;
}
pos = strchr(pos, ':');
if (pos == NULL) {
return false;
}
pos++;
while (*pos == ' ') {
pos++;
}
char *end;
unsigned long value = strtoul(pos, &end, 10);
if (end == pos) {
return false;
}
*out = (uint32_t)value;
return true;
}
/* GETs the server's /frame/config -- doubles as both the reachability
* check (any completed HTTP response means the socket-level connection
* succeeded) and the source of the server-configurable refresh interval. */
static frame_server_config_t fetch_frame_config(const char *toolsserver)
{
frame_server_config_t result = {
.reachable = false,
.refresh_interval_s = CONFIG_FRAME_SLEEP_INTERVAL_S,
};
char url[160];
snprintf(url, sizeof(url), "http://%s/frame/config", toolsserver);
esp_http_client_config_t config = {
.url = url,
.method = HTTP_METHOD_GET,
.timeout_ms = CONFIG_FRAME_SERVER_CHECK_TIMEOUT_MS,
};
esp_http_client_handle_t client = esp_http_client_init(&config);
esp_err_t err = esp_http_client_open(client, 0);
if (err != ESP_OK) {
ESP_LOGW(TAG, "Server '%s' not reachable: %s", toolsserver, esp_err_to_name(err));
esp_http_client_cleanup(client);
return result;
}
esp_http_client_fetch_headers(client);
result.reachable = true;
char body[256];
int total = 0;
int n;
while (total < (int)sizeof(body) - 1 &&
(n = esp_http_client_read(client, body + total, sizeof(body) - 1 - total)) > 0) {
total += n;
}
body[total] = '\0';
esp_http_client_close(client);
esp_http_client_cleanup(client);
uint32_t interval;
if (json_extract_uint(body, "refresh_interval_s", &interval)) {
result.refresh_interval_s = interval;
} else {
ESP_LOGW(TAG, "'%s' response missing refresh_interval_s, using fallback %ds", url,
(int)result.refresh_interval_s);
}
return result;
}
typedef struct {
esp_http_client_handle_t client;
} http_read_ctx_t;
/* Pulls the next chunk straight out of the in-progress HTTP response --
* epd_display_stream() calls this to feed the panel without ever holding
* the full ~192KB frame in RAM. */
static size_t http_read_fn(uint8_t *chunk, size_t chunk_size, void *ctx_)
{
http_read_ctx_t *ctx = (http_read_ctx_t *)ctx_;
int n = esp_http_client_read(ctx->client, (char *)chunk, (int)chunk_size);
return n > 0 ? (size_t)n : 0;
}
/* GETs /frame/image and streams the response directly into the panel.
* *out_started_stream tells the caller whether the panel was actually
* touched -- false means the failure happened before any pixel data was
* sent (bad status, connection error), so nothing was drawn this cycle. */
static esp_err_t fetch_and_display(const frame_config_t *cfg, bool *out_started_stream)
{
*out_started_stream = false;
char url[160];
snprintf(url, sizeof(url), "http://%s/frame/image", cfg->toolsserver);
esp_http_client_config_t config = {
.url = url,
.method = HTTP_METHOD_GET,
.timeout_ms = CONFIG_FRAME_FETCH_TIMEOUT_MS,
};
esp_http_client_handle_t client = esp_http_client_init(&config);
esp_err_t err = esp_http_client_open(client, 0);
if (err != ESP_OK) {
ESP_LOGE(TAG, "Failed to open '%s': %s", url, esp_err_to_name(err));
esp_http_client_cleanup(client);
return err;
}
int content_length = esp_http_client_fetch_headers(client);
int status = esp_http_client_get_status_code(client);
if (status != 200) {
ESP_LOGE(TAG, "'%s' returned HTTP %d", url, status);
esp_http_client_close(client);
esp_http_client_cleanup(client);
return ESP_FAIL;
}
ESP_LOGI(TAG, "Fetching frame (%d bytes) from '%s'", content_length, url);
*out_started_stream = true;
http_read_ctx_t ctx = { .client = client };
err = epd_display_stream(http_read_fn, &ctx);
esp_http_client_close(client);
esp_http_client_cleanup(client);
return err;
}
void frame_client_run(const frame_config_t *cfg)
{
esp_err_t epd_err = epd_init();
bool have_display = (epd_err == ESP_OK);
if (!have_display) {
ESP_LOGW(TAG, "EPD init failed (%s), continuing without display", esp_err_to_name(epd_err));
}
/* Always show the status screen on the first successful connection
* after (re)provisioning, regardless of outcome -- confirms the
* connection worked. Skipped on later wakes to save a refresh, except
* when something's actually wrong (handled below). */
bool first_connection = !frame_config_has_connected_once();
if (first_connection) {
frame_config_mark_connected_once();
if (have_display) {
status_screen_show(cfg->sta_ssid, STATUS_OK, cfg->toolsserver, STATUS_PENDING);
}
}
frame_server_config_t server_cfg = fetch_frame_config(cfg->toolsserver);
uint32_t sleep_seconds = server_cfg.refresh_interval_s;
if (!server_cfg.reachable) {
/* Nothing's been drawn yet this cycle (aside from the optional
* PENDING screen above), so this is cheap diagnostics without
* compounding flashing. */
ESP_LOGW(TAG, "Tools server not reachable, retrying sooner");
sleep_seconds = CONFIG_FRAME_RETRY_INTERVAL_S;
if (have_display) {
status_screen_show(cfg->sta_ssid, STATUS_OK, cfg->toolsserver, STATUS_FAILED);
}
} else {
if (first_connection && have_display) {
status_screen_show(cfg->sta_ssid, STATUS_OK, cfg->toolsserver, STATUS_OK);
}
if (have_display) {
bool stream_started = false;
esp_err_t fetch_err = fetch_and_display(cfg, &stream_started);
if (fetch_err != ESP_OK) {
ESP_LOGW(TAG, "Fetch/display failed (%s), retrying sooner", esp_err_to_name(fetch_err));
sleep_seconds = CONFIG_FRAME_RETRY_INTERVAL_S;
if (!stream_started) {
/* The panel was never touched this cycle (e.g. a bad
* HTTP status before any pixel data was sent) -- show
* the failure instead of leaving whatever was on
* screen before. A mid-stream failure, by contrast,
* already refreshed the panel with something, so
* skip compounding it with a second refresh here. */
status_screen_show(cfg->sta_ssid, STATUS_OK, cfg->toolsserver, STATUS_FAILED);
}
}
}
}
if (have_display) {
epd_sleep();
}
ESP_LOGI(TAG, "Deep sleeping for %u seconds", (unsigned)sleep_seconds);
esp_sleep_enable_timer_wakeup((uint64_t)sleep_seconds * 1000000ULL);
esp_deep_sleep_start();
}