Bonjour
premier retour après mise sous tension d'un des petit module d'AI-Thinker contenant un ESP32-C3 (à processeur Risc-V)
pour relier l'alimentation, Tx et Rx j'ai soudé des fils rigides à l'envers du module sur 6 connections au pas de 2,54mm (ces 6 connections permettraient un flashage ou 'téléversement')

Sur une mini plaque d'essai le module ne prend pas beaucoup de place !

A la mise sous tension l'ESP32-C3 est assez bavard .....(une cinquantaine de lignes d'infos jusqu'au 'ready')
Je constate qu'il est livré avec un firmware AT récent et bien fourni , avec entre autres ce qu'il faut pour MQTT
la commande AT+GSLP met la puce en deep-sleep et je constate que le courant est bien celui annoncé pour cette puce : 5 µA. 
ci dessous le fichier log du démarrage de la puce et de la réponse à quelques commandes AT, dont celle qui donne la version du firmware et celle qui liste les commandes disponibles
⸮ESP-ROM:esp32c3-api1-20210207
08:55:26.008 -> Build:Feb 7 2021
08:55:26.008 -> rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
08:55:26.008 -> SPIWP:0xee
08:55:26.008 -> mode:DIO, clock div:2
08:55:26.008 -> load:0x3fcd6100,len:0x1758
08:55:26.008 -> load:0x403ce000,len:0x894
08:55:26.008 -> load:0x403d0000,len:0x2c5c
08:55:26.008 -> entry 0x403ce000
08:55:26.041 -> e[0;32mI (53) boot: ESP-IDF v4.3-beta3 2nd stage bootloadere[0m
08:55:26.041 -> e[0;32mI (53) boot: compile time 18:22:41e[0m
08:55:26.075 -> e[0;32mI (53) boot: chip revision: 3e[0m
08:55:26.075 -> e[0;32mI (55) boot.esp32c3: SPI Speed : 40MHze[0m
08:55:26.075 -> e[0;32mI (60) boot.esp32c3: SPI Mode : DIOe[0m
08:55:26.075 -> e[0;32mI (65) boot.esp32c3: SPI Flash Size : 4MBe[0m
08:55:26.075 -> e[0;32mI (69) boot: Enabling RNG early entropy source...e[0m
08:55:26.075 -> e[0;32mI (75) boot: Partition Table:e[0m
08:55:26.075 -> e[0;32mI (78) boot: ## Label Usage Type ST Offset Lengthe[0m
08:55:26.108 -> e[0;32mI (86) boot: 0 phy_init RF data 01 01 0000f000 00001000e[0m
08:55:26.108 -> e[0;32mI (93) boot: 1 otadata OTA data 01 00 00010000 00002000e[0m
08:55:26.108 -> e[0;32mI (101) boot: 2 nvs WiFi data 01 02 00012000 0000e000e[0m
08:55:26.108 -> e[0;32mI (108) boot: 3 at_customize unknown 40 00 00020000 000e0000e[0m
08:55:26.108 -> e[0;32mI (116) boot: 4 ota_0 OTA app 00 10 00100000 00180000e[0m
08:55:26.141 -> e[0;32mI (123) boot: 5 ota_1 OTA app 00 11 00280000 00180000e[0m
08:55:26.141 -> e[0;32mI (131) boot: End of partition tablee[0m
08:55:26.141 -> e[0;32mI (135) esp_image: segment 0: paddr=00100020 vaddr=3c0e0020 size=22da0h (142752) mape[0m
08:55:26.194 -> e[0;32mI (175) esp_image: segment 1: paddr=00122dc8 vaddr=3fc8e600 size=02ea4h ( 11940) loade[0m
08:55:26.194 -> e[0;32mI (178) esp_image: segment 2: paddr=00125c74 vaddr=40380000 size=0a3a4h ( 41892) loade[0m
08:55:26.194 -> e[0;32mI (190) esp_image: segment 3: paddr=00130020 vaddr=42000020 size=d7b18h (883480) mape[0m
08:55:26.372 -> e[0;32mI (381) esp_image: segment 4: paddr=00207b40 vaddr=4038a3a4 size=041d8h ( 16856) loade[0m
08:55:26.372 -> e[0;32mI (385) esp_image: segment 5: paddr=0020bd20 vaddr=50000000 size=00004h ( 4) loade[0m
08:55:26.405 -> e[0;32mI (387) esp_image: segment 6: paddr=0020bd2c vaddr=50000008 size=00010h ( 16) loade[0m
08:55:26.405 -> e[0;32mI (399) boot: Loaded app from partition at offset 0x100000e[0m
08:55:26.405 -> e[0;32mI (401) boot: Disabling RNG early entropy source...e[0m
08:55:26.505 ->
08:55:26.505 -> ################################################
08:55:26.505 -> arch:ESP32C3, 3
08:55:26.505 -> compile_time:Ai-Thinker|B&T
08:55:26.505 -> ble_mac:7cDFA1a44DE5
08:55:26.505 -> wifi_mac:7cDFA1a44DE4
08:55:26.505 -> sdk_version:v4.3-beta3
08:55:26.505 -> firmware_version:2.1.0(MINI-1)
08:55:26.505 -> compile_time:May 18 2021 18:23:12
08:55:26.505 ->
08:55:26.505 -> ready
08:55:26.505 ->
08:55:26.505 -> ################################################
08:55:26.639 ->
08:55:26.639 -> ready
08:55:34.007 -> AT
08:55:34.007 ->
08:55:34.007 -> OK
08:55:45.917 -> AT+CWMODE?
08:55:45.917 -> +CWMODE:2
08:55:45.917 ->
08:55:45.917 -> OK
08:56:02.763 -> AT+GMR
08:56:02.763 -> AT version:2.2.0.0-dev(b211bcb - ESP32C3 - Apr 30 2021 10:16:08)
08:56:02.815 -> SDK version:v4.3-beta3
08:56:02.815 -> compile time(eb9efff):May 18 2021 18:23:12
08:56:02.815 -> Bin version:2.1.0(MINI-1)
08:56:02.815 ->
08:56:02.815 -> OK
08:56:19.645 -> AT+CMD?
08:56:19.645 -> +CMD:0,"AT",0,0,0,1
08:56:19.645 -> +CMD:1,"ATE0",0,0,0,1
08:56:19.645 -> +CMD:2,"ATE1",0,0,0,1
08:56:19.645 -> +CMD:3,"AT+RST",0,0,0,1
08:56:19.645 -> +CMD:4,"AT+GMR",0,0,0,1
08:56:19.645 -> +CMD:5,"AT+CMD",0,1,0,0
08:56:19.645 -> +CMD:6,"AT+GSLP",0,0,1,0
08:56:19.645 -> +CMD:7,"AT+SYSTIMESTAMP",0,1,1,0
08:56:19.645 -> +CMD:8,"AT+SLEEP",0,1,1,0
08:56:19.645 -> +CMD:9,"AT+RESTORE",0,0,0,1
08:56:19.645 -> +CMD:10,"AT+SYSRAM",0,1,0,0
08:56:19.691 -> +CMD:11,"AT+SYSFLASH",0,1,1,0
08:56:19.691 -> +CMD:12,"AT+RFPOWER",0,1,1,0
08:56:19.691 -> +CMD:13,"AT+SYSMSG",0,1,1,0
08:56:19.691 -> +CMD:14,"AT+SYSROLLBACK",0,0,0,1
08:56:19.691 -> +CMD:15,"AT+SYSLOG",0,1,1,0
08:56:19.691 -> +CMD:16,"AT+SYSSTORE",0,1,1,0
08:56:19.691 -> +CMD:17,"AT+SLEEPWKCFG",0,0,1,0
08:56:19.691 -> +CMD:18,"AT+SYSREG",0,0,1,0
08:56:19.691 -> +CMD:19,"AT+USERRAM",0,1,1,0
08:56:19.691 -> +CMD:20,"AT+CWMODE",0,1,1,0
08:56:19.691 -> +CMD:21,"AT+CWSTATE",0,1,0,0
08:56:19.691 -> +CMD:22,"AT+CWJAP",0,1,1,1
08:56:19.691 -> +CMD:23,"AT+CWRECONNCFG",0,1,1,0
08:56:19.691 -> +CMD:24,"AT+CWLAP",0,0,1,1
08:56:19.691 -> +CMD:25,"AT+CWLAPOPT",0,0,1,0
08:56:19.691 -> +CMD:26,"AT+CWQAP",0,0,0,1
08:56:19.691 -> +CMD:27,"AT+CWSAP",0,1,1,0
08:56:19.691 -> +CMD:28,"AT+CWLIF",0,0,0,1
08:56:19.712 -> +CMD:29,"AT+CWQIF",0,0,1,1
08:56:19.712 -> +CMD:30,"AT+CWDHCP",0,1,1,0
08:56:19.712 -> +CMD:31,"AT+CWDHCPS",0,1,1,0
08:56:19.712 -> +CMD:32,"AT+CWSTAPROTO",0,1,1,0
08:56:19.712 -> +CMD:33,"AT+CWAPPROTO",0,1,1,0
08:56:19.712 -> +CMD:34,"AT+CWAUTOCONN",0,1,1,0
08:56:19.712 -> +CMD:35,"AT+CWHOSTNAME",0,1,1,0
08:56:19.712 -> +CMD:36,"AT+CWCOUNTRY",0,1,1,0
08:56:19.745 -> +CMD:37,"AT+CIFSR",0,0,0,1
08:56:19.745 -> +CMD:38,"AT+CIPSTAMAC",0,1,1,0
08:56:19.745 -> +CMD:39,"AT+CIPAPMAC",0,1,1,0
08:56:19.745 -> +CMD:40,"AT+CIPSTA",0,1,1,0
08:56:19.745 -> +CMD:41,"AT+CIPAP",0,1,1,0
08:56:19.745 -> +CMD:42,"AT+CIPV6",0,1,1,0
08:56:19.745 -> +CMD:43,"AT+CIPDNS",0,1,1,0
08:56:19.745 -> +CMD:44,"AT+CIPDOMAIN",0,0,1,0
08:56:19.745 -> +CMD:45,"AT+CIPSTATUS",0,0,0,1
08:56:19.745 -> +CMD:46,"AT+CIPSTART",0,0,1,0
08:56:19.745 -> +CMD:47,"AT+CIPSTARTEX",0,0,1,0
08:56:19.745 -> +CMD:48,"AT+CIPTCPOPT",0,1,1,0
08:56:19.778 -> +CMD:49,"AT+CIPCLOSE",0,0,1,1
08:56:19.778 -> +CMD:50,"AT+CIPSEND",0,0,1,1
08:56:19.778 -> +CMD:51,"AT+CIPSENDEX",0,0,1,0
08:56:19.778 -> +CMD:52,"AT+CIPDINFO",0,1,1,0
08:56:19.778 -> +CMD:53,"AT+CIPMUX",0,1,1,0
08:56:19.778 -> +CMD:54,"AT+CIPRECVMODE",0,1,1,0
08:56:19.778 -> +CMD:55,"AT+CIPRECVDATA",0,0,1,0
08:56:19.778 -> +CMD:56,"AT+CIPRECVLEN",0,1,0,0
08:56:19.778 -> +CMD:57,"AT+CIPSERVER",0,1,1,0
08:56:19.778 -> +CMD:58,"AT+CIPSERVERMAXCONN",0,1,1,0
08:56:19.778 -> +CMD:59,"AT+CIPSSLCCONF",0,1,1,0
08:56:19.778 -> +CMD:60,"AT+CIPSSLCCN",0,1,1,0
08:56:19.812 -> +CMD:61,"AT+CIPSSLCSNI",0,1,1,0
08:56:19.812 -> +CMD:62,"AT+CIPSSLCALPN",0,1,1,0
08:56:19.812 -> +CMD:63,"AT+CIPSSLCPSK",0,1,1,0
08:56:19.812 -> +CMD:64,"AT+CIPMODE",0,1,1,0
08:56:19.812 -> +CMD:65,"AT+CIPSTO",0,1,1,0
08:56:19.812 -> +CMD:66,"AT+SAVETRANSLINK",0,0,1,0
08:56:19.812 -> +CMD:67,"AT+CIPSNTPCFG",0,1,1,0
08:56:19.812 -> +CMD:68,"AT+CIPSNTPTIME",0,1,0,0
08:56:19.812 -> +CMD:69,"AT+CIPRECONNINTV",0,1,1,0
08:56:19.812 -> +CMD:70,"AT+MQTTUSERCFG",0,0,1,0
08:56:19.812 -> +CMD:71,"AT+MQTTCLIENTID",0,0,1,0
08:56:19.850 -> +CMD:72,"AT+MQTTUSERNAME",0,0,1,0
08:56:19.850 -> +CMD:73,"AT+MQTTPASSWORD",0,0,1,0
08:56:19.850 -> +CMD:74,"AT+MQTTCONNCFG",0,0,1,0
08:56:19.850 -> +CMD:75,"AT+MQTTCONN",0,1,1,0
08:56:19.850 -> +CMD:76,"AT+MQTTPUB",0,0,1,0
08:56:19.850 -> +CMD:77,"AT+MQTTPUBRAW",0,0,1,0
08:56:19.850 -> +CMD:78,"AT+MQTTSUB",0,1,1,0
08:56:19.850 -> +CMD:79,"AT+MQTTUNSUB",0,0,1,0
08:56:19.850 -> +CMD:80,"AT+MQTTCLEAN",0,0,1,0
08:56:19.850 -> +CMD:81,"AT+HTTPCLIENT",0,0,1,0
08:56:19.850 -> +CMD:82,"AT+HTTPGETSIZE",0,0,1,0
08:56:19.850 -> +CMD:83,"AT+HTTPCPOST",0,0,1,0
08:56:19.850 -> +CMD:84,"AT+MDNS",0,0,1,0
08:56:19.850 -> +CMD:85,"AT+WPS",0,0,1,0
08:56:19.850 -> +CMD:86,"AT+CWSTARTSMART",0,0,1,1
08:56:19.878 -> +CMD:87,"AT+CWSTOPSMART",0,0,0,1
08:56:19.878 -> +CMD:88,"AT+PING",0,0,1,0
08:56:19.878 -> +CMD:89,"AT+CIUPDATE",0,1,1,1
08:56:19.878 -> +CMD:90,"AT+LEDTEST",0,0,1,0
08:56:19.878 -> +CMD:91,"AT+UART",0,1,1,0
08:56:19.878 -> +CMD:92,"AT+UART_CUR",0,1,1,0
08:56:19.878 -> +CMD:93,"AT+UART_DEF",0,1,1,0
Je n'y trouve pas les commandes AT pour Bluetooth BLE, comandes présentes dans certains firmwares AT pour ESP32 
Ayant eu du mal à mettre la main sur des firmwares AT récents je décide de conserver ce module tel quel , par exemple pour ajouter de la connectivité une carte Raspberry Pi Pico en bénéficiant d'un firmware AT récent.
Les commandes de ces firmwares sont maintenant bien documentées par Espressif
Un arrivage permettra de tester prochaînement un autre 'ESP32-C3 sous IDE Arduino !