steinhelge
a544594769
- cabin_node: subscribes to local MQTT (ESPHome sensors), sends temperature, battery voltage/SOC and switch states over LoRa SF12 - cabin_gw: receives LoRa packets, publishes JSON to home MQTT broker - Bidirectional: gateway forwards ON/OFF commands from home HA to node - cabin_node always in RX mode (12V powered) — commands arrive instantly - ESPHome config for ESP32 on teknisk rom: Victron MPPT BLE + JBD BMS BLE + DS18B20 temperatures + GPIO switches for varme/VVB Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
21 lines
507 B
C
21 lines
507 B
C
#pragma once
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#include <stdint.h>
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#include <stddef.h>
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#include <string.h>
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#include "mbedtls/md.h"
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#include "config.h"
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// Returns a 4-byte truncated HMAC-SHA256 over `data` of `len` bytes.
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inline uint32_t hmac_sig(const uint8_t *data, size_t len)
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{
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static const char *key = HMAC_KEY;
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uint8_t out[32];
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mbedtls_md_hmac(
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mbedtls_md_info_from_type(MBEDTLS_MD_SHA256),
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reinterpret_cast<const uint8_t *>(key), strlen(key),
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data, len, out);
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uint32_t sig;
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memcpy(&sig, out, 4);
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return sig;
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}
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