Build and Field Notes

Build-time and hardware-integration knowledge for thesada-fw that does not belong to a single runtime subsystem. Runtime behaviour lives in the other firmware pages; this one holds build targets, the release workflow, and modem-integration notes.

Build targets

main builds ESP32-S3 targets only. The PlatformIO environments and the boards they map to are listed in the hardware table. Each environment selects its module set at compile time.

Classic ESP32 variants (WROOM, CYD, Ethernet) are maintained on a separate track and are not produced from main. Do not expect main to build a non-S3 image.

Release and versioning

Bump FIRMWARE_VERSION in src/thesada_config.h before the merge commit that ships the release, then tag that commit.

The source of truth for the running version is thesada_config.h plus the git tags - never a version line written into prose docs. Bumping before the merge avoids having to force-move a tag that was placed ahead of the version constant.

Cellular mTLS (SIM7080G)

mTLS over the SIM7080G is sensitive to the exact AT-command order. SIM7080G modem firmware 1951B17 silently fails the TLS handshake with the “obvious” concatenated-PEM approach.

Upload the CA, client certificate, and client key to the modem filesystem as three separate files (server-ca.crt, client.crt, client.key), then:

+CSSLCFG="SSLVERSION",0,3                        # TLS 1.2 on SSL context 0
+CSSLCFG="CONVERT",2,"server-ca.crt"             # convert CA (type 2)
+CSSLCFG="CONVERT",1,"client.crt","client.key"   # convert client cert + key (type 1, 4-arg)
+CSSLCFG="sni",0,"<broker>"                       # optional; ignored harmlessly on a direct broker
+SMSSL=1,"server-ca.crt","client.crt"            # mode 1 = mutual TLS

Field notes:

Do not concatenate cert and key into one PEM and use +SMSSL=2. It returns OK but the handshake never completes on fw 1951B17. The 4-arg CONVERT,1 flow above is the working pattern.
The client key must be PKCS#8, not SEC1. Validated with both RSA-2048 and ECDSA P-256 client certs.
Yield the AT bus between cellular MQTT retries. If the modem loops on SMCONN failure without releasing the bus, the main loop starves.
Reference AT samples: LilyGo’s published T-SIM7080G SSL and MQTT example sketches at github.com/Xinyuan-LilyGO/LilyGo-T-SIM7080G.