Added espnow module with documentation.
This commit is contained in:
Jade Mattsson
Jade Mattsson
parent
bd6b70ee61
commit
830522ac33
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@ -8,6 +8,7 @@ set(module_srcs
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"dht.c"
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"encoder.c"
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"eromfs.c"
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"espnow.c"
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"file.c"
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"gpio.c"
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"heaptrace.c"
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@ -82,6 +82,12 @@ menu "NodeMCU modules"
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store the directory path as part of the filename just as SPIFFS
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does.
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config NODEMCU_CMODULE_ESPNOW
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bool "ESP-NOW module"
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default "n"
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help
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Includes the espnow module.
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config NODEMCU_CMODULE_ETH
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depends on IDF_TARGET_ESP32
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select ETH_USE_ESP32_EMAC
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@ -0,0 +1,390 @@
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/*
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* Copyright 2024 Dius Computing Pty Ltd. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of the copyright holders nor the names of
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* its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
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* THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
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* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* @author Jade Mattsson <jmattsson@dius.com.au>
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*/
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#include "module.h"
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#include "platform.h"
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#include "ip_fmt.h"
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#include "task/task.h"
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#include "lauxlib.h"
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#include "esp_now.h"
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#include "esp_wifi.h"
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#include "esp_err.h"
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#if ESP_NOW_ETH_ALEN != 6
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# error "MAC address length assumption broken"
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#endif
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#if ESP_NOW_MAX_DATA_LEN > 0xffff
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# error "Update len field in received_packet_t"
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#endif
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typedef struct {
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uint8_t src[6];
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uint8_t dst[6];
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int16_t rssi;
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uint16_t len; // ESP_NOW_MAX_DATA_LEN is currently 250
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char data[0];
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} received_packet_t;
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typedef struct {
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uint8_t dst[6];
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esp_now_send_status_t status;
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} sent_packet_t;
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static task_handle_t espnow_task = 0;
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static int recv_ref = LUA_NOREF;
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static int sent_ref = LUA_NOREF;
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// --- Helper functions -----------------------------------
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static int *cb_ref_for_event(const char *name)
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{
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if (strcmp("receive", name) == 0)
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return &recv_ref;
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else if (strcmp("sent", name) == 0)
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return &sent_ref;
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else
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return NULL;
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}
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static int hexval(lua_State *L, char c)
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{
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if (c >= '0' && c <= '9')
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return c - '0';
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else if (c >= 'A' && c <= 'F')
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return c - 'A' + 10;
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else if (c >= 'a' && c <= 'f')
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return c - 'a' + 10;
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else
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return luaL_error(L, "invalid hex digit '%c'", c);
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}
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// TODO: share with wifi_sta.c
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static bool parse_mac(const char *str, uint8_t out[6])
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{
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const char *fmts[] = {
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"%hhx%hhx%hhx%hhx%hhx%hhx",
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"%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
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"%hhx-%hhx-%hhx-%hhx-%hhx-%hhx",
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"%hhx %hhx %hhx %hhx %hhx %hhx",
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NULL
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};
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for (unsigned i = 0; fmts[i]; ++i)
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{
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if (sscanf (str, fmts[i],
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&out[0], &out[1], &out[2], &out[3], &out[4], &out[5]) == 6)
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return true;
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}
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return false;
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}
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static void on_receive(const esp_now_recv_info_t *info, const uint8_t *data, int len)
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{
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if (len < 0)
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return; // Don't do that.
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received_packet_t *p = malloc(sizeof(received_packet_t) + len);
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if (!p)
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{
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NODE_ERR("out of memory\n");
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return;
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}
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memcpy(p->src, info->src_addr, sizeof(p->src));
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memcpy(p->dst, info->des_addr, sizeof(p->dst));
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p->rssi = info->rx_ctrl->rssi;
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p->len = len;
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memcpy(p->data, data, len);
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if (!task_post_high(espnow_task, (task_param_t)p))
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{
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NODE_ERR("lost esp-now packet; task queue full\n");
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free(p);
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}
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}
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static void on_sent(const uint8_t *mac, esp_now_send_status_t status)
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{
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sent_packet_t *p = malloc(sizeof(sent_packet_t));
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if (!p)
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{
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NODE_ERR("out of memory\n");
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return;
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}
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memcpy(p->dst, mac, sizeof(p->dst));
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p->status = status;
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if (!task_post_medium(espnow_task, (task_param_t)p))
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{
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NODE_ERR("lost esp-now packet; task queue full\n");
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free(p);
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}
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}
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static void espnow_task_fn(task_param_t param, task_prio_t prio)
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{
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lua_State* L = lua_getstate();
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int top = lua_gettop(L);
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luaL_checkstack(L, 3, "");
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if (prio == TASK_PRIORITY_HIGH) // received packet
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{
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received_packet_t *p = (received_packet_t *)param;
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if (recv_ref != LUA_NOREF)
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{
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lua_rawgeti (L, LUA_REGISTRYINDEX, recv_ref);
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lua_createtable(L, 0, 4); // src, dst, rssi, data
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char mac[MAC_STR_SZ];
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macstr(mac, p->src);
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lua_pushstring(L, mac);
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lua_setfield(L, -2, "src");
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macstr(mac, p->dst);
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lua_pushstring(L, mac);
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lua_setfield(L, -2, "dst");
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lua_pushinteger(L, p->rssi);
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lua_setfield(L, -2, "rssi");
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lua_pushlstring(L, p->data, p->len);
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lua_setfield(L, -2, "data");
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luaL_pcallx(L, 1, 0);
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}
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free(p);
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}
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else if (prio == TASK_PRIORITY_MEDIUM) // sent
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{
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sent_packet_t *p = (sent_packet_t *)param;
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if (sent_ref != LUA_NOREF)
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{
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lua_rawgeti (L, LUA_REGISTRYINDEX, sent_ref);
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char dst[MAC_STR_SZ];
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macstr(dst, p->dst);
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lua_pushstring(L, dst);
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if (p->status == ESP_NOW_SEND_SUCCESS)
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lua_pushinteger(L, 1);
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else
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lua_pushnil(L);
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luaL_pcallx(L, 2, 0);
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}
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free(p);
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}
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lua_settop(L, top); // restore original before exit
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}
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static void err_check(lua_State *L, esp_err_t err)
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{
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if (err != ESP_OK)
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luaL_error(L, "%s", esp_err_to_name(err));
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}
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// --- Lua interface functions -----------------------------------
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static int lespnow_start(lua_State *L)
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{
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err_check(L, esp_now_init());
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err_check(L, esp_now_register_recv_cb(on_receive));
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err_check(L, esp_now_register_send_cb(on_sent));
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return 0;
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}
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static int lespnow_stop(lua_State *L)
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{
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err_check(L, esp_now_unregister_send_cb());
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err_check(L, esp_now_unregister_recv_cb());
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err_check(L, esp_now_deinit());
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return 0;
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}
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static int lespnow_getversion(lua_State *L)
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{
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uint32_t ver;
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err_check(L, esp_now_get_version(&ver));
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lua_pushinteger(L, ver);
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return 1;
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}
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// espnow.on('sent' or 'received', cb)
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// sent -> cb('ma:ca:dd:00:11:22', status)
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// received -> cb({ src=, dst=, data=, rssi= })
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static int lespnow_on(lua_State *L)
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{
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const char *evtname = luaL_checkstring(L, 1);
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int *ref = cb_ref_for_event(evtname);
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if (!ref)
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return luaL_error(L, "unknown event type");
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if (lua_isnoneornil(L, 2))
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{
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if (*ref != LUA_NOREF)
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{
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luaL_unref(L, LUA_REGISTRYINDEX, *ref);
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*ref = LUA_NOREF;
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}
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}
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else if (lua_isfunction(L, 2))
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{
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if (*ref != LUA_NOREF)
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luaL_unref(L, LUA_REGISTRYINDEX, *ref);
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lua_pushvalue(L, 2);
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*ref = luaL_ref(L, LUA_REGISTRYINDEX);
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}
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else
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return luaL_error(L, "expected function");
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return 0;
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}
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// espnow.send('ma:ca:dd:00:11:22' or nil, str)
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static int lespnow_send(lua_State *L)
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{
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const char *mac = luaL_optstring(L, 1, NULL);
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size_t payloadlen = 0;
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const char *payload = luaL_checklstring(L, 2, &payloadlen);
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uint8_t peer_addr[6];
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if (mac && !parse_mac(mac, peer_addr))
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return luaL_error(L, "bad peer address");
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err_check(L, esp_now_send(
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mac ? peer_addr : NULL, (const uint8_t *)payload, payloadlen));
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return 0;
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}
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// espnow.addpeer('ma:ca:dd:00:11:22', { lmk=, channel=, encrypt= }
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static int lespnow_addpeer(lua_State *L)
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{
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esp_now_peer_info_t peer_info;
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memset(&peer_info, 0, sizeof(peer_info));
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const char *mac = luaL_checkstring(L, 1);
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wifi_mode_t mode = WIFI_MODE_NULL;
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err_check(L, esp_wifi_get_mode(&mode));
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switch (mode)
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{
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case WIFI_MODE_STA: peer_info.ifidx = WIFI_IF_STA; break;
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case WIFI_MODE_APSTA: // fall-through
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case WIFI_MODE_AP: peer_info.ifidx = WIFI_IF_AP; break;
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default: return luaL_error(L, "No wifi interface found");
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}
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if (!parse_mac(mac, peer_info.peer_addr))
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return luaL_error(L, "bad peer address");
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lua_settop(L, 2); // Discard excess parameters, to ensure we have space
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if (lua_istable(L, 2))
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{
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lua_getfield(L, 2, "encrypt");
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peer_info.encrypt = luaL_optint(L, -1, 0);
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lua_pop(L, 1);
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if (peer_info.encrypt)
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{
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lua_getfield(L, 2, "lmk");
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size_t lmklen = 0;
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const char *lmkstr = luaL_checklstring(L, -1, &lmklen);
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lua_pop(L, 1);
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if (lmklen != 2*sizeof(peer_info.lmk))
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return luaL_error(L, "LMK must be %d hex digits", 2*ESP_NOW_KEY_LEN);
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for (unsigned i = 0; i < sizeof(peer_info.lmk); ++i)
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peer_info.lmk[i] =
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(hexval(L, lmkstr[i*2]) << 4) + hexval(L, lmkstr[i*2 +1]);
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}
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lua_getfield(L, 2, "channel");
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peer_info.channel = luaL_optint(L, -1, 0);
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lua_pop(L, 1);
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}
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err_check(L, esp_now_add_peer(&peer_info));
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return 0;
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}
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// espnow.delpeer('ma:ca:dd:00:11:22')
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static int lespnow_delpeer(lua_State *L)
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{
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const char *mac = luaL_checkstring(L, 1);
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uint8_t peer_addr[6];
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if (!parse_mac(mac, peer_addr))
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return luaL_error(L, "bad peer address");
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err_check(L, esp_now_del_peer(peer_addr));
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return 0;
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}
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static int lespnow_setpmk(lua_State *L)
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{
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uint8_t pmk[ESP_NOW_KEY_LEN] = { 0, };
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size_t len = 0;
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const char *str = luaL_checklstring(L, 1, &len);
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if (len != sizeof(pmk) * 2)
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return luaL_error(L, "PMK must be %d hex digits", 2*ESP_NOW_KEY_LEN);
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for (unsigned i = 0; i < sizeof(pmk); ++i)
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pmk[i] = (hexval(L, str[i*2]) << 4) + hexval(L, str[i*2 +1]);
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err_check(L, esp_now_set_pmk(pmk));
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return 0;
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}
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static int lespnow_setwakewindow(lua_State *L)
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{
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int n = luaL_checkint(L, 1);
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if (n < 0 || n > 0xffff)
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return luaL_error(L, "wake window out of bounds");
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err_check(L, esp_now_set_wake_window(n));
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return 0;
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}
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static int lespnow_init(lua_State *L)
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{
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espnow_task = task_get_id(espnow_task_fn);
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return 0;
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}
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LROT_BEGIN(espnow, NULL, 0)
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LROT_FUNCENTRY( start, lespnow_start )
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LROT_FUNCENTRY( stop, lespnow_stop )
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LROT_FUNCENTRY( getversion, lespnow_getversion )
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LROT_FUNCENTRY( on, lespnow_on ) // 'receive', 'sent'
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LROT_FUNCENTRY( send, lespnow_send )
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LROT_FUNCENTRY( addpeer, lespnow_addpeer )
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LROT_FUNCENTRY( delpeer, lespnow_delpeer )
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LROT_FUNCENTRY( setpmk, lespnow_setpmk )
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LROT_FUNCENTRY( setwakewindow, lespnow_setwakewindow )
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LROT_END(espnow, NULL, 0)
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NODEMCU_MODULE(ESPNOW, "espnow", espnow, lespnow_init);
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@ -0,0 +1,247 @@
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# ESP-NOW Module
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| Since | Origin / Contributor | Maintainer | Source |
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| :----- | :-------------------- | :---------- | :------ |
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| 2024-03-07 | [Jade Mattsson](https://github.com/jmattsson) |[Jade Mattsson](https://github.com/jmattsson) | [espnow.c](../../components/modules/espnow.c)|
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The `espnow` module provides an interface to Espressif's [ESP-NOW functionality](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/network/esp_now.html). To quote their documentation directly:
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"ESP-NOW is a kind of connectionless Wi-Fi communication protocol that is defined by Espressif. In ESP-NOW, application data is encapsulated in a vendor-specific action frame and then transmitted from one Wi-Fi device to another without connection."
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Packets can be sent to either individual peers, the whole list of defined peers, or broadcast to everyone in range. For non-broadcast packets, ESP-NOW provides optional encryption support to prevent eavesdropping. To use encryption, a "Primary Master Key" (PMK) should first be set. When registering a peer, a peer-specific "Local Master Key" (LMK) is then given, which is further encrypted by the PMK. All packets sent to that peer will be encrypted with the resulting key.
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To broadcast packets, a peer with address 'ff:ff:ff:ff:ff:ff' must first be registered. Broadcast packets do not support encryption, and attempting to enable encrypting when registering the broadcast peer will result in an error.
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ESP-NOW uses a WiFi vendor-specific action frame to transmit data, and as such it requires the WiFi stack to have been started before ESP-NOW packets can be sent and received.
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## espnow.start
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Starts the ESP-NOW stack. While this may be called prior to `wifi.start()`, packet transmission and reception will not be possible until after the WiFi stack has been started.
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#### Syntax
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```lua
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espnow.start()
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```
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#### Parameters
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None.
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#### Returns
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`nil`
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An error will be raised if the ESP-NOW stack cannot be started.
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## espnow.stop
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|
||||
Stops the ESP-NOW stack.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.stop()
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
None.
|
||||
|
||||
#### Returns
|
||||
`nil`
|
||||
|
||||
An error will be raised if the ESP-NOW stack cannot be stopped.
|
||||
|
||||
|
||||
## espnow.getversion
|
||||
|
||||
Returns the raw version number enum value. Currently, it is `1`. Might be useful for checking version compatibility in the future.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
ver = espnow.getversion()
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
None.
|
||||
|
||||
#### Returns
|
||||
An integer representing the ESP-NOW version.
|
||||
|
||||
|
||||
## espnow.setpmk
|
||||
|
||||
Sets the Primary Master Key (PMK). When using security, this should be done prior to adding any peers, as their LMKs will be encrypted by the current PMK.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.setpmk(pmk)
|
||||
```
|
||||
#### Parameters
|
||||
`pmk` The Primary Master Key, given as a hex-encoding of a 16-byte key (i.e. the `pmk` should consist of 32 hex digits.
|
||||
|
||||
#### Returns
|
||||
`nil`
|
||||
|
||||
An error will be raised if the PMK cannot be set.
|
||||
|
||||
#### Example
|
||||
```lua
|
||||
espnow.setpmk('00112233445566778899aabbccddeeff')
|
||||
```
|
||||
|
||||
|
||||
## espnow.setwakewindow
|
||||
|
||||
Controls the wake window during which ESP-NOW listens. In most cases this should never need to be changed from the default. Refer to the Espressif documentation for further details.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.setwakewindow(window)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
`window` An integer between 0 and 65535.
|
||||
|
||||
#### Returns
|
||||
`nil`
|
||||
|
||||
|
||||
## espnow.addpeer
|
||||
|
||||
Registers a peer MAC address. Optionally parameters for the peer may be included, such as encryption key.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.addpeer(mac, options)
|
||||
```
|
||||
#### Parameters
|
||||
`mac` The peer mac address, given as a string in `00:11:22:33:44:55` format (colons optional, and may also be replaced by '-' or ' ').
|
||||
`options` A table with with following entries:
|
||||
- `channel` An integer indicating the WiFi channel to be used. The default is `0`, indicating that the current WiFi channel should be used. If non-zero, must match the current WiFi channel.
|
||||
- `lmk` The LMK for the peer, if encryption is to be used.
|
||||
- `encrypt` A non-zero integer to indicate encryption should be enabled. When set, makes `lmk` a required field.
|
||||
|
||||
#### Returns
|
||||
`nil`
|
||||
|
||||
An error will be raised if a peer cannot be added, such as if the peer list if full, or the peer has already been added.
|
||||
|
||||
#### Examples
|
||||
|
||||
Adding a peer without encryption enabled.
|
||||
```lua
|
||||
espnow.addpeer('7c:df:a1:c1:4c:71')
|
||||
```
|
||||
|
||||
Adding a peer with encryption enabled. Please use randomly generated keys instead of these easily guessable placeholders.
|
||||
```lua
|
||||
espnow.setpmk('ffeeddccbbaa99887766554433221100')
|
||||
espnow.addpeer('7c:df:a1:c1:4c:71', { encrypt = 1, lmk = '00112233445566778899aabbccddeeff' })
|
||||
```
|
||||
|
||||
## espnow.delpeer
|
||||
|
||||
Deletes a previously added peer from the internal peer list.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.delpeer(mac)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
`mac` The MAC address of the peer to delete.
|
||||
|
||||
#### Returns
|
||||
`nil`
|
||||
|
||||
Returns an error if the peer cannot be deleted.
|
||||
|
||||
|
||||
## espnow.on
|
||||
|
||||
Registers or unregisters callback handlers for the ESP-NOW events.
|
||||
|
||||
There are two events available, `sent` which is issued in response to a packet send request and which reports the status of the send attempt, and 'receive' which is issued when an ESP-NOW packet is successfully received.
|
||||
|
||||
Only a single callback function can be registered for each event.
|
||||
|
||||
The callback function for the `sent` event is invoked with two parameters, the destination MAC address, and a `1`/`nil` to indicate whether the send was believed to be successful or not.
|
||||
|
||||
The callback function for the `receive` event is invoked with a single parameter, a table with the following keys:
|
||||
- `src` The sender MAC address
|
||||
- `dst` The destination MAC address (likely either the local MAC of the receiver, or the broadcast address)
|
||||
- `rssi` The RSSI value from the packet, indicating signal strength between the two devices
|
||||
- `data` The actual payload data, as a string. The string may contain binary data.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.on(event, callbackfn)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
`event` The event name, one of `sent` or `receive`.
|
||||
`callbackfn` The callback function to register, or `nil` to unregister the previously set callback function for the event.
|
||||
|
||||
#### Returns
|
||||
`nil`
|
||||
|
||||
Raises an error if invalid arguments are given.
|
||||
|
||||
#### Example
|
||||
Registering callback handlers.
|
||||
```lua
|
||||
espnow.on('sent',
|
||||
function(mac, success) print(mac, success and 'Yay!' or 'Noooo') end)
|
||||
espnow.on('receive',
|
||||
function(t) print(t.src, '->', t.dst, '@', t.rssi, ':', t.data) end)
|
||||
```
|
||||
|
||||
Unregistering callback handlers.
|
||||
```lua
|
||||
espnow.on('sent') -- implicit nil
|
||||
espnow.on('receive', nil)
|
||||
```
|
||||
|
||||
|
||||
## espnow.send
|
||||
|
||||
Attempts to send an ESP-NOW packet to one or more peers.
|
||||
|
||||
In general it is strongly recommended to use the encryption functionality, as this ensures not only secrecy but also prevent unintentional interference between different users of ESP-NOW.
|
||||
|
||||
If you do need to use broadcasts or multicasts, you should make sure to have a unique, recognisable marker at the start of the payload to make filtering out unwanted messages easy, both for you and other ESP-NOW users.
|
||||
|
||||
#### Syntax
|
||||
```lua
|
||||
espnow.send(peer, data)
|
||||
```
|
||||
|
||||
#### Parameters
|
||||
`peer` The peer MAC address to send to. Must have previously been added via `espnow.addpeer()`. If `peer` is given as `nil`, the packet is sent to all registered non-broadcast/multicast peers, and the `sent` callback is invoked for each of those peers.
|
||||
`data` A string of data to send. May contain binary bytes. Maximum supported length at the time of writing is 250 bytes.
|
||||
|
||||
#### Returns
|
||||
`nil`, but the `sent` callback is invoked with the status afterwards.
|
||||
|
||||
Raises an error if the peer is not valid, or other fatal errors preventing a send attempt from even being made. The `sent` callback will not be invoked in this case.
|
||||
|
||||
#### Example
|
||||
Broadcasting a message to every single ESP-NOW device in range.
|
||||
```lua
|
||||
bcast='ff:ff:ff:ff:ff:ff'
|
||||
espnow.addpeer(bcast)
|
||||
espnow.send(bcast, '[NodeMCU] Hello, world!')
|
||||
```
|
||||
|
||||
Sending a directed message to one specific ESP-NOW device.
|
||||
```lua
|
||||
peer='7c:df:a1:c1:4c:71'
|
||||
espnow.addpeer(peer)
|
||||
espnow.send(peer, 'Hello, you!')
|
||||
```
|
||||
|
||||
Sending a message to all registered peers.
|
||||
```lua
|
||||
espnow.addpeer('7c:df:a1:c1:4c:71')
|
||||
espnow.addpeer('7c:df:a1:c1:4c:47')
|
||||
espnow.addpeer('7c:df:a1:c1:4f:12')
|
||||
espnow.send(nil, 'Hello, peers!')
|
||||
```
|
||||
|
|
@ -48,6 +48,7 @@ nav:
|
|||
- 'dht': 'modules/dht.md'
|
||||
- 'encoder': 'modules/encoder.md'
|
||||
- 'eromfs': 'modules/eromfs.md'
|
||||
- 'espnow': 'modules/espnow.md'
|
||||
- 'eth': 'modules/eth.md'
|
||||
- 'file': 'modules/file.md'
|
||||
- 'gpio': 'modules/gpio.md'
|
||||
|
|
|
|||
Loading…
Reference in New Issue