0 Fork 0

Files

T

Add comprehensive spec audit results and pyMC_core issue reports

- CHANGELOG.md: Full audit findings organized by severity
- PYMC_CORE_ISSUES.md: 7 evidence-based bug reports for pyMC_core
  (wrong constants, broken path_len decoding, wrong TRACE hash,
  wrong SNR calculation)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Add comprehensive spec audit results and pyMC_core issue reports

- CHANGELOG.md: Full audit findings organized by severity
- PYMC_CORE_ISSUES.md: 7 evidence-based bug reports for pyMC_core
  (wrong constants, broken path_len decoding, wrong TRACE hash,
  wrong SNR calculation)
- Remove ERRATA.md: contents already covered by audit findings

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

2026-04-01 21:37:57 -06:00

1.7 KiB

Raw Blame History

MeshCore Protocol Specification

Section 4: Payload — ACK

Overview

The ACK (acknowledgment) payload is the simplest payload type. It consists of a single 4-byte CRC value used to confirm receipt of a previously sent message. The CRC is computed by the sender from the original message's timestamp, text, and sender public key.

Payload Type

Header payload type field: 0x03 (ACK)

Wire Format

 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      ACK CRC (uint32_le)                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Fields

Field	Offset	Size	Type	Description
ack_crc	0	4 bytes	uint32_le	CRC identifying the acknowledged message

Encoding

Compute the 4-byte CRC value for the message being acknowledged.
Write the CRC as a little-endian 32-bit unsigned integer.
Set payload_len to 4.

Decoding

Read 4 bytes from the payload as a little-endian uint32.
If fewer than 4 bytes are available, the packet is INVALID.

Constraints

The payload MUST be exactly 4 bytes.
Implementations SHOULD log or discard ACK packets with payload_len < 4.

Cross-References

Section 1: Wire Format — Packet framing
Section 11: Multipart — Multipart ACK encoding
Test vectors: corpus/payloads/ack/

Reference Implementation

Mesh::createAck() in src/Mesh.cpp
ACK reception in Mesh::onRecvPacket(), case PAYLOAD_TYPE_ACK

1.7 KiB Raw Blame History