From fcb1966b8fc49557ec1ee492d24c587ee314bf59 Mon Sep 17 00:00:00 2001 From: Timur Iskhodzhanov Date: Sun, 13 Jun 2021 18:59:36 -0700 Subject: [PATCH] Minor tweaks --- can_db/ft86.md | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/can_db/ft86.md b/can_db/ft86.md index da15ff7..912d7fc 100644 --- a/can_db/ft86.md +++ b/can_db/ft86.md @@ -18,14 +18,22 @@ Engine RPM | 320 | `C + (D & 0x3f) * 256` | Coolant temperature | 864 | `D - 40` | Engine oil temperature | 864 | `C - 40` | -Here are a few data channels that might be useful for more detailed analysis, -but due to limited Bluetooth bandwidth, adding them might affect the update rate -of the more essential channels: +Below is a table with a few more data channels that might be useful for more +detailed analysis. When adding more channels, be aware that it might negatively +affect the update rate of the more essential channels, due to limited Bluetooth +bandwidth. However, the communication protocol in RaceChrono is smart enough to +optimize Bluetooth usage if multiple channels share the same PID. As a general +rule, if a new channel has the same PID as an existing channel (such as +"Throttle position" using the same PID 320 as "Accelerator position"), then +adding it should not affect the update rates. Adding a channel based on +a new PID (such as "Wheel speed FL") will likely affect the update rates of all +other channels. Channel name | PID | Equation | Notes ------------ | --- | -------- | ----- Brake pressure | 209 | `C * 100` | Not sure about the units / multiplier yet. Clutch position | 320 | `B & 0x80 / 1.28` | Only 0% and "not 0%", unfortunately. +Gear | 321 | `(G & 0xf) * (1 - (min(G & 0xf, 7)) / 7)` | Car calculates it based on speed, RPM and clutch position. It's pretty slow. I really doubt it's worth wasting one PID for this channel. It's not that hard to see which gear you're in based on speed and RPM in data. Throttle position | 320 | `G / 2.55` | This is the throttle *valve*, not pedal. Lateral acceleration | 208 | `bytesToIntLe(raw, 6, 1) * 0.2` | Data is noisy. Longitudinal acceleration | 208 | `bytesToIntLe(raw, 7, 1) * -0.1` | Data is noisy.