From 645bad819efda04a4bc25e60ded9697ac828d1a5 Mon Sep 17 00:00:00 2001 From: Mikkeli Date: Wed, 14 Oct 2026 00:19:22 +0900 Subject: [PATCH] BOM: the second module is a WT61 plus (TTL); the WT61 datasheet may not apply to it Co-Authored-By: Claude Opus 5.5 Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz --- docs/BOM.md | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/docs/BOM.md b/docs/BOM.md index 225dcb4..44b565c 100644 --- a/docs/BOM.md +++ b/docs/BOM.md @@ -166,7 +166,10 @@ Header facts (carrier board spec SP-11324-001 v1.3, Table 3-3 and 5-3; raw copy "TTL level", so if it is ever fed 5 V, first check that its idle TX reads ~3.3 V. - Power comes from the header's 3.3 V supply pin (1 or 17), a regulated rail on the carrier board. Not from a GPIO: a GPIO pin is a signal and is not meant to power anything. -- **The second module (2026-10-14) speaks WitMotion's newer register protocol, not the 3-byte commands** in smart-serow's `IMU.md`: +- **The second module (2026-10-14) is a different product: "WitMotion WT61 plus, TTL version"**, in different packaging. The WT61 + datasheet v24-0429 (the KB's) describes the plain WT61 and may not apply to it; rates, defaults and commands below are what this module + did, not what that datasheet says. Its own manual is still to find. +- **It speaks WitMotion's newer register protocol, not the 3-byte commands** in smart-serow's `IMU.md`: it ignored `FF AA 63`. It came at 9600 baud / 10 Hz (a rate the datasheet does not list). Commands are 5 bytes, `FF AA `, each run as **unlock `FF AA 69 88 B5`, the write, save `FF AA 00 00 00`**, all at the module's current baud. Done on the car Orin, checking after each step: