Decode your cars OEM CAN signals

CAN Decoder — Build Guide

Build a CAN capture and decode pipeline with AI. Core: USB adapter + Mac. Recommended: phone GPS + map for much better signal discovery.

What You're Building

Core (required): capture CAN traffic from a USB adapter and decode signals.

Optional but strongly recommended: record GPS and visualize on a map. This gives you — and the AI — much better context when figuring out what each CAN ID means.

Why GPS + map matter for decoding

Raw CAN captures are hard to interpret alone. GPS altitude turns a drive into a natural experiment — hills give you predictable physical changes to hunt for in the data. You can ask the AI things like:

  • "Find RPM — it should be much higher when driving up hills"
  • "Find coolant temp — it should increase as we climb and decrease as we descend"

The map makes those altitude changes visible and easy to line up with CAN timestamps. Give the AI a capture with GPS and it can correlate bytes to real terrain instead of guessing from raw hex.

Hardware & OBD-II wiring

Required

  • USB CAN adapter (CANable, XCAN-USB/PCAN clone)
  • OBD-II breakout cable (often included) or jumper wires pushed into the OBD-II port pins
  • Mac laptop

Recommended

  • iPhone on Personal Hotspot (phone controls capture; Mac stays plugged into CAN)
  • Mapbox access token (free tier is fine, for map demo)

OBD-II wiring

Most USB-CAN kits use a standard OBD-II cable. Or use jumper wires inserted directly into the OBD-II socket on pins 6, 14, and 5.

Pin Function
6 CAN High
14 CAN Low
5 Signal ground (connect adapter GND here)
16 +12V (some adapters need this for power)
  • Bitrate is usually 500 kbit/s on OBD-II CAN.
  • Adapter CAN H → pin 6, CAN L → pin 14, GND → pin 5.

OBD-II may not show OEM traffic

The OBD port is meant for diagnostics. On many vehicles the gateway filters the bus — you see OBD request/response traffic (e.g. 0x7DF, 0x7E0) but not the full OEM broadcast frames where RPM, coolant, throttle, etc. actually live.

Quick check: if you only see diagnostic IDs and never high-rate broadcast IDs while the engine runs, OBD sniffing won't work for decoding on that vehicle.

If OEM CAN is filtered, tapping the bus elsewhere (ECU, BCM, harness) is vehicle-specific and risky — probably not worth it for this guide.

Roles

Device Role
MacBook Server — CAN adapter, capture files, HTTPS API. Set up once, leave running in the car.
Phone Remote control — open one page, tap Start / Stop. GPS streams automatically while recording.
Capture format (CSV)

Use CSV for everything — simple for humans and AI to read, easy to join on timestamp.

CAN capture (capture-<timestamp>.csv):

timestamp,can_id,data0,data1,data2,data3,data4,data5,data6,data7
1718190000.123,0x1F9,00,00,1A,F0,00,00,00,00

timestamp = Unix epoch seconds (wall clock, UTC) — same basis as GPS

GPS log (gps-<timestamp>.csv):

timestamp,datetime_utc,latitude,longitude,speed_kmh,altitude_m,heading_deg,fix_quality,satellites,source

Signal definitions (signals.csv):

name,can_id,start_bit,length,endian,signed,factor,offset,unit,notes
RPM,0x1F9,16,16,little,false,0.125,0,RPM,payload bytes 2-3 BE16; physical = raw / 8
Engine Coolant Temperature,0x551,0,8,little,false,1,-40,°C,payload byte 0; physical = raw - 40

One row per decoded signal. The map and analysis tools read this file to know how to extract values from raw CAN frames.

Build order + AI prompts
1. CAN sniffer CLI 
Build cansniffer.py with python-can: --list, --probe, live frame print,
--log to CSV with Unix epoch timestamp per frame, --bitrate (500k default),
slcan + pcan support.

CSV columns: timestamp, can_id, data0..data7 (hex or decimal).
2. Capture server (Mac) 
Build cansniffer_gui.py: HTTPS server on :8765. Mac connects to USB CAN adapter.

Desktop page (optional): bitrate select, live frame preview, session status.

Mobile page at / (or /capture): large Start / Stop buttons only.
On Start: begin CAN logging to captures/<session>/capture-*.csv and accept GPS posts.
On Stop: flush files and end session. Rotate capture CSV at 100k frames.

Mac is always the server; phone is the remote control.

HTTPS is required for phone GPS. iPhone Safari blocks navigator.geolocation on plain http://.

HTTPS prompt (add when building step 2 or 4)

Add HTTPS to the capture server using a self-signed certificate:

- On first start, if certs are missing, run openssl via subprocess to create:
  .certs/server.pem and .certs/server-key.pem
  (openssl req -x509 -newkey rsa:2048 -nodes -days 3650 -subj "/CN=REVVGAUGE-CAN")
- Wrap the HTTPServer with ssl.SSLContext (TLS 1.2+), load_cert_chain
- Bind 0.0.0.0 so the phone can reach the Mac over hotspot
- Print https:// URLs (not http) including Mac LAN IP for phone access
- Require openssl on the Mac (pre-installed on macOS)

On iPhone: user accepts the certificate warning once (Show Details → visit website).
Without HTTPS, GPS will not work on the phone.
3. Find your vehicle's signals 
Analyze capture-*.csv (and gps-*.csv if available) to discover CAN signals.
Use terrain context where possible: RPM higher uphill, coolant rising on climbs, etc.

Write results to signals.csv with columns:
name, can_id, start_bit, length, endian, signed, factor, offset, unit, notes

One row per signal (RPM, throttle, coolant, gear, …). Document the byte layout
and formula in notes so humans and AI can verify later.
4. Mobile capture + GPS (optional, recommended) 
On the same HTTPS server, mobile Start/Stop also enables phone GPS automatically:
- Start → navigator.geolocation.watchPosition() + POST /api/gps (~1 Hz)
- GPS rows append to gps-*.csv in the active session folder
- Stop → stop GPS watch and close session

Columns: timestamp (Unix epoch), lat, lon, speed_kmh, altitude, heading.
Show https://<mac-ip>:8765/ on Mac at startup. Phone joins via hotspot.
5. Merge GPS + CAN (optional, recommended) 
Build session_data.py: load capture-*.csv, gps-*.csv, and signals.csv.
Join GPS to CAN on timestamp (±3s). Apply signals.csv to decode frame bytes.
Output GeoJSON for the map.
6. Map (optional, recommended) 
Build map_demo/server.py (:8766) + Mapbox frontend: session picker,
route colored by speed/RPM/throttle, hover tooltips.
First test

Minimum (CAN only — Mac)

  1. Plug CAN adapter into Mac, start server: python sniff/cansniffer_gui.py
  2. On Mac browser: Start capture, run engine / drive briefly, Stop
  3. Check session folder has capture-*.csv
  4. Ask AI to analyze the capture and produce signals.csv (see step 3 prompt)

Recommended (phone control + map)

Mac stays in the car as server; you drive with your phone:

  1. Mac: python sniff/cansniffer_gui.py (set bitrate once if needed)
  2. iPhone hotspot on → Mac connected
  3. iPhone Safari: open https://<mac-ip>:8765/ (accept cert warning once)
  4. Tap Start, drive 5+ min on a hilly route, tap Stop
  5. Check session folder on Mac has capture-*.csv and gps-*.csv
  6. MAPBOX_ACCESS_TOKEN=pk... python sniff/map_demo/server.py → review route on map
  7. Feed capture + GPS + map context to AI for signals.csv

Prompting AI with GPS context

When asking AI to decode unknown signals, include:

  • The capture-*.csv from the session
  • The gps-*.csv from the same session (if available)
  • A physical expectation tied to terrain: "RPM should rise on uphill sections", "coolant should warm on long climbs and cool on descents"

Example:

Here's a CAN capture CSV and matching GPS CSV from the same drive.
Altitude climbs ~200 m between timestamps 1718190000 and 1718190120, then drops on the way back.
Find RPM — it should be noticeably higher on the uphill sections.
Find coolant temp — it should trend up while climbing and down while descending.

Write confirmed signals to signals.csv in the standard format.
Sync model (GPS + CAN)

If you add GPS, both CSVs join on wall-clock timestamp — no separate stitch step.

Source Time
GPS CSV timestamp = Unix epoch
CAN CSV timestamp = Unix epoch

Both use the same clock. Mac and iPhone should be on the same network (hotspot) with reasonable clock sync.

Common fixes
  • No frames → ignition on, try 500k bitrate; check pins 6/14 (CAN H/L) and ground on pin 5
  • Frames but only OBD diagnostic IDs → vehicle likely filters OEM CAN at the OBD port; tapping elsewhere is out of scope
  • No GPS → must use https:// (not http); accept self-signed cert on phone once; allow location on first Start
  • SSL / connection errors → another process may be on port 8765; stop old server and restart
  • No RPM on map → check signals.csv CAN IDs and byte layout for your vehicle
  • One adapter = one app → close other CAN tools first
  • Decoding stuck → record a GPS session on a hilly route; give AI both CSVs with terrain-based prompts

Tip: Build core capture on the Mac first. Add the phone Start/Stop page when you're ready to decode — hills + GPS give AI much better signal-discovery context.

V1

Installation manual

Follow these steps to unbox, wire, and install your Revv Gauge.

Important if you plan to use the gauge in a vehicle: Revvgauge is an auxiliary information display and is not intended to replace or disable any original vehicle safety system, required tell-tale, warning indicator, or federally required vehicle instrument. Installation must not interfere with airbags, required lighting, driver visibility, or other safety equipment. For off-road use only.

  1. Open the box

    Inside you should find your Revvgauge and the standard loom, plus any sensors or extra cables included with your order.

    Contents of the Revvgauge box
    Revv Gauge, standard loom, and any sensors or extra cables

  2. Protective screen cover

    Don’t be alarmed if the screen looks scratched — that’s just the plastic protective cover. It can be removed by taking off the bezel.

    We recommend only removing the protective cover once installation is complete.
    Removing the bezel
    Remove the bezel
    Peeling off the plastic protective cover
    Peel off the plastic protective cover

  3. Choose your power connection

    Are you using the standard loom or the OBD2 cable?

  4. How to insert cables into the Micro-Fit Molex

    Every loom wire ends in a pre-crimped Micro-Fit terminal. These push into the back of the 16-pin Molex housing until they click and lock.

    Hold the wire near the crimp and insert the metal terminal thin end first into the correct cavity. The terminal only seats one way — locking tabs must line up with the cavity. If it feels stuck, stop and check the orientation rather than forcing it.

    Push firmly until you feel/hear a click. Give the wire a gentle tug to confirm it’s locked. Use this same method for power, ground, and every other input or output cable.

    Correct Micro-Fit terminal orientation
    Correct — locking tabs aligned with the cavity
    Incorrect Micro-Fit terminal orientation
    Incorrect — do not force a rotated terminal

  5. Decide which cables to insert

    Choose which cables your gauge will need and insert them now using the method above. If you’re on the standard loom, start with power and ground. If you’re using the OBD2 cable, GND, VIN (power), and the CAN pins are already populated — you can skip those and only insert any other cables you need. The lighting input is also pre-populated with a short (~20 cm) cable; extend it with your standard loom cable or another wire to the desired location. Tap the pin layout image to view it full screen for reference.

    Inserting additional input pins into the Micro-Fit Molex
    Insert your remaining wires into the Molex
    16-pin Molex layout — tap to enlarge

  6. Move to your install location

    You’re ready to move to where you’ll mount the gauge — car, tiny home, caravan, or elsewhere. Roughly route the wiring from the power source to the mount location.

    Installing in a car and planning to use a lot of analog sensors? Pull the analog inputs, the +5V wire, and one of the GND wires through the firewall. That keeps fewer wires running through the dash.

  7. Wire in your device

    With the loom prepared and wires roughly routed, you can begin wiring the gauge into your vehicle or setup. Open the sections that apply to your install.

  8. Mount the device

    Mount the gauge in your chosen location. If you’re using a gauge pod or similar, it’s recommended to wrap some electrical tape around the body to increase the diameter until it’s a tight fit.

    The gauge uses an M52×2 thread. Print the lock ring STEP to help secure the device, or download the case STEP if you want to design your own gauge pod.

    Download lock ring (STEP) Download case (STEP)

  9. Download the app

    Download REVV Editor, then follow the in-app instructions to connect your gauge, load a layout, and finish setup.

    Download on the App Store Get it on Google Play

Custom CAN

Custom CAN values

Revv uses bit-style definitions rather than byte-style. Use this simple calculator to take your CAN protocol’s byte definition and convert it into Revv’s bit style.

Legal

REVVGAUGE Gauge Unit V1.0 — Terms and Conditions of Sale and Use

  • Document: TC-REVVGAUGE-V1.0 — Rev 1
  • Product: REVVGAUGE Gauge Unit V1.0 (Model RVG-52)
  • Effective date: 8 August 2026

Important — Intended use

The REVVGAUGE Gauge Unit V1.0 is an aftermarket general-purpose instrumentation accessory for non-road and off-grid applications. It is intended for uses such as off-grid living, recreational and competition off-road vehicles, agricultural and industrial equipment, caravans, and similar 12–24 V systems.

It is not intended, approved, or warranted for use as a primary road-legal vehicle instrument cluster, or for any application where applicable road vehicle standards, registration rules, or roadworthiness laws require OEM or ADR-/FVMSS-compliant instrumentation.

By purchasing, installing, or using the Product, you acknowledge and agree that:

  • the Product is for the intended non-road and off-grid uses described in these Terms;
  • you will not rely on the Product as a sole or primary source of safety-critical information;
  • you are solely responsible for ensuring that any installation and use complies with all applicable laws in your jurisdiction; and
  • use of the Product contrary to these Terms (including as a primary public-road instrument) is at your own risk and may void warranty coverage to the maximum extent permitted by law.

Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.

Nothing in these Terms excludes, restricts or modifies any consumer guarantee, right or remedy conferred on you by the Australian Consumer Law or any other applicable law that cannot be excluded, restricted or modified by agreement.

1. Parties and acceptance

1.1 These Terms and Conditions (Terms) apply to the sale and use of the REVVGAUGE Gauge Unit V1.0 by REVVGAUGE PTY LTD, trading as Revv Gauge (Revv Gauge, we, us, our).

1.2 By placing an order, completing a purchase, installing, configuring, or using the Product, you (you, Purchaser, Customer) agree to be bound by these Terms.

1.3 If you do not agree to these Terms, you must not purchase, install, or use the Product.

1.4 These Terms should be read together with the separate REVVGAUGE Gauge Unit V1.0 Product Warranty (Warranty). Where there is any inconsistency between these Terms and the Warranty in respect of warranty remedies, the Warranty prevails for that subject matter, subject always to the Australian Consumer Law.

2. Product description

2.1 The Product is a general-purpose multifunction 52 mm programmable digital gauge (Model RVG-52), supplied as a complete assembled unit together with any Revv Gauge accessories included at the time of purchase (such as a wiring loom and mounting hardware, if supplied).

2.2 The Product is intended as a configurable information display and data interface for applications such as off-grid homes, off-road vehicles, caravans, industrial equipment, and similar 12–24 V systems. Exact software features may vary by firmware version.

2.3 V1.0 interface note: Connector pins 3 and 4 are additional analog inputs (AIN5 and AIN6). This revision does not include a K-type thermocouple interface. Connecting a thermocouple directly to pins 3 or 4 is not supported and may damage the unit.

2.4 Separately purchased sensors, third-party components, and accessories not included with the Product are not covered by these Terms except as expressly stated at the time of purchase.

3. Intended use

3.1 The Product is designed and sold for non-road and off-grid applications as described in these Terms.

3.2 Without limiting clause 3.1, the Product is intended for use as a supplementary instrumentation display in off-grid homes, caravans, off-road vehicles, motorsport and competition vehicles, agricultural machinery, industrial equipment, and similar non-road or stationary applications operating from a nominal 12 V to 24 V DC supply.

3.3 The Product is not intended for:

  • 3.3.1 use as a primary OEM replacement instrument cluster for vehicles used on public roads;
  • 3.3.2 marine applications;
  • 3.3.3 aviation or safety-critical control systems;
  • 3.3.4 medical devices; or
  • 3.3.5 any application where failure of the Product could reasonably be expected to result in personal injury, death, or property damage without independent fail-safe systems.

3.4 The Product is an informational accessory. Readings, alerts, outputs, and displayed values may be incomplete, delayed, inaccurate, or unavailable due to sensor fault, wiring fault, configuration error, electrical noise, CAN bus conditions, firmware behaviour, or other causes. You must not rely solely on the Product for safety-critical decisions, system protection, or legal compliance.

3.5 You are solely responsible for verifying that any installation and use of the Product is lawful in your jurisdiction, including any applicable registration, roadworthiness, electrical, building, or instrumentation requirements.

4. Electrical and operating limits

4.1 You must operate the Product only within the published specifications, including without limitation:

Parameter Specification
Supply voltage (VIN) 12 V to 24 V nominal (operate within published limits)
Gauge 5 V output 5 V, 200 mA maximum continuous
Analog inputs AIN1–AIN6; 0 V to 5 V linear, or NTC (100 Ω to 50 kΩ)
CAN bus CAN H / CAN L; 10 kbit/s to 1 Mbit/s
Digital outputs Open-drain low-side; 1 W maximum per output @ 12 V
Lighting input Headlamp / dimmer sense input (where used)
Operating temperature –40 °C to +85 °C

4.2 Operating the Product outside the specified supply voltage, current, temperature, or interface ratings may cause permanent damage and may void the Warranty to the maximum extent permitted by law.

4.3 Absolute maximum and transient conditions described in design documentation are design limits, not an invitation to operate at those extremes in normal use.

5. Installation and configuration

5.1 Revv Gauge recommends that the Product be installed by a qualified electrician or technician familiar with 12–24 V DC electrical systems.

5.2 You must:

  • 5.2.1 fuse the VIN supply appropriately for the installation;
  • 5.2.2 route wiring away from heat sources and moving parts, and protect harnesses with suitable conduit where required;
  • 5.2.3 observe correct CAN bus topology and termination practice;
  • 5.2.4 connect only supported sensors and loads within rated limits;
  • 5.2.5 not apply external voltage to the +5 V output; and
  • 5.2.6 follow all installation, configuration, and commissioning instructions supplied by Revv Gauge.

5.3 Incorrect installation, reverse polarity (beyond protected limits), overcurrent, unsupported sensors, incorrect CAN wiring, or modification of the Product may cause damage to the Product, the host system, or other equipment, for which you accept responsibility to the maximum extent permitted by law.

6. Orders, pricing, and payment

6.1 An order placed through our website or authorised sales channel constitutes an offer to purchase. We may accept or reject an order at our discretion.

6.2 Prices are as displayed at the time of order unless otherwise agreed in writing. We may correct obvious pricing errors.

6.3 Title in the Product passes to you on receipt of cleared payment in full. Risk in the Product passes on delivery to you or your nominated carrier, unless otherwise required by law.

6.4 You are only entitled to Warranty benefits after all amounts owing in respect of the Product have been paid.

7. Shipping and delivery

7.1 Delivery timeframes are estimates only and are not guaranteed.

7.2 You must provide accurate delivery details. We are not responsible for delays or loss caused by incorrect address information, refusal of delivery, or carrier events beyond our reasonable control.

7.3 International orders may be subject to customs duties, taxes, and import restrictions, which are your responsibility unless expressly stated otherwise.

8. Returns and Australian Consumer Law

8.1 Nothing in these Terms limits your rights under the Australian Consumer Law.

8.2 Change-of-mind returns, if offered, are at our discretion and may be subject to conditions published at the time of sale (including return shipping and restocking, where lawful).

8.3 Faulty goods claims are handled in accordance with the Australian Consumer Law and, where applicable, the Warranty.

9. Warranty

9.1 The Product is supplied with a separate twelve (12) month limited Warranty against defects in materials and workmanship, subject to the exclusions and claim procedures set out in that Warranty.

9.2 Without limiting the Warranty, coverage may be declined where damage or failure results from misuse, incorrect installation, operation outside specifications, unsupported connections, unauthorised modification, or use contrary to these Terms (including use other than the intended use described in clause 3), to the maximum extent permitted by law.

10. Software and updates

10.1 Firmware and software supplied with the Product are licensed, not sold. You receive a limited, non-exclusive, non-transferable licence to use the software solely with the Product.

10.2 You must not reverse engineer, decompile, or modify the firmware except to the extent expressly permitted by law.

10.3 We may provide firmware updates from time to time. Updates may change features, fix defects, or alter behaviour. You are responsible for applying updates in accordance with our instructions. We do not guarantee uninterrupted or error-free operation.

11. Intellectual property

11.1 All intellectual property in the Product, documentation, firmware, branding, designs, and related materials remains owned by Revv Gauge or its licensors.

11.2 Third-party components and open-source software included in the Product remain subject to their original licences and terms.

12. Limitation of liability

12.1 To the maximum extent permitted by law, Revv Gauge is not liable for:

  • 12.1.1 loss of profits, revenue, data, goodwill, or opportunity;
  • 12.1.2 indirect, incidental, special, or consequential loss;
  • 12.1.3 damage to vehicles, equipment, property, systems, or downtime arising from use of the Product;
  • 12.1.4 loss arising from reliance on displayed values, alerts, or outputs; or
  • 12.1.5 loss arising from use of the Product contrary to the intended use in clause 3 (including as a primary public-road instrument).

12.2 To the maximum extent permitted by law, our aggregate liability arising out of or in connection with the Product or these Terms is limited to the amount you paid for the Product giving rise to the claim, or, where the Australian Consumer Law requires, to repairing or replacing the Product or paying the cost of repair or replacement.

12.3 Where the Australian Consumer Law applies and liability cannot be excluded, our liability for a breach of a consumer guarantee is limited, to the extent permitted, to one or more of: replacement of the goods; repair of the goods; payment of the cost of replacing the goods; or payment of the cost of having the goods repaired.

13. Indemnity

13.1 To the maximum extent permitted by law, you indemnify Revv Gauge against claims, losses, damages, costs, and expenses (including reasonable legal fees) arising out of or in connection with:

  • 13.1.1 your installation, configuration, or use of the Product;
  • 13.1.2 your failure to follow instructions or these Terms;
  • 13.1.3 use of the Product other than for the intended use described in clause 3; and
  • 13.1.4 any modification of the Product or combination with third-party parts not approved by Revv Gauge,

except to the extent caused by our negligence or breach of a non-excludable consumer guarantee.

14. Unauthorised sales and resupply

14.1 If you acquired the Product for the purpose of resupply, the Warranty may not apply as stated in the Warranty document.

14.2 Sale of the Product via an online auction or unauthorised reseller may affect Warranty eligibility, as Revv Gauge has no control over storage, handling, quality, or safety of Products sold through such channels.

15. Force majeure

15.1 Revv Gauge is not liable for delay or failure to perform caused by events beyond our reasonable control, including acts of God, war, riots, strikes, epidemic, fire, flood, storm, changes in law or public policy, terrorism, supply-chain disruption, or carrier failure.

16. Privacy

16.1 If you provide personal information when purchasing or contacting support, we will handle it in accordance with our privacy practices as published on https://revvgauge.com (or as otherwise notified to you).

17. Variations

17.1 We may update these Terms from time to time by publishing a revised version. The Terms in force at the time of your purchase apply to that purchase, unless a change is required by law.

17.2 Agents, officers, employees, distributors, and resellers are not authorised to vary these Terms unless agreed by Revv Gauge in writing.

18. Severability

18.1 If any provision of these Terms is illegal, unenforceable, or invalid, that provision is to be read down or severed to the minimum extent necessary, and the remaining provisions continue in full force.

19. Governing law

19.1 These Terms are governed by the laws of Australia (and, where applicable, the State or Territory in which REVVGAUGE PTY LTD principally carries on business). The courts of that jurisdiction have non-exclusive jurisdiction, subject to any non-excludable consumer rights in your place of residence.

20. Contact

Revv Gauge

Email: support@revvgauge.com

Website: https://revvgauge.com

For warranty claims, follow the claim procedure in the Product Warranty and contact support@revvgauge.com.

Copyright © 2026 Revv Gauge. All rights reserved.

Sensors

Boost sensor calibration

The REVV Boost Sensor measures absolute pressure, so it needs a quick zero calibration after install. This page explains why, what that means for your reading range, and how to dial it in.

What absolute pressure means

Absolute pressure is measured from a perfect vacuum — not from the air around you. On an absolute scale, empty space is 0, and normal atmospheric pressure at sea level is about 1 bar (≈ 100 kPa / 14.7 PSI).

Absolute

Starts at vacuum = 0. Atmosphere sits near 1 bar. This is what the sensor physically measures.

0 → 4 bar abs

Gauge (what you see)

Zero at atmosphere. Negative under vacuum, positive under boost — the scale drivers expect.

−1 → +3 bar

Because the REVV sensor reports absolute pressure, the gauge converts that into a familiar gauge reading by subtracting atmospheric pressure. Atmosphere changes slightly with weather and altitude, so after install the display may sit a little above or below 0 until you calibrate it.

Why this covers −1 to 3 bar

The sensor’s useful absolute range is roughly 0 to 4 bar. Once that is referenced to atmosphere (~1 bar absolute), the same span becomes a gauge reading of about −1 to +3 bar.

Same physical range, two ways of reading it — zeroed at local atmosphere.

Near full vacuum

~0 bar abs −1 bar

Atmosphere

~1 bar abs 0

Peak boost

~4 bar abs +3 bar

How to calibrate

Once the gauge is properly installed and turned on, you will likely notice it reads slightly above or below 0 — especially if you are using kPa or PSI. That offset is normal with an absolute sensor.

  1. Note the offset

    With the engine off and the sensor open to atmosphere (or already installed but not under boost/vacuum), read the value shown on the gauge. Write down how far it is above or below 0.

  2. Open Advanced Settings

    In the designer, go to the Sensor tab, find the boost sensor config, and open Advanced Settings.

  3. Use Modify Reading

    Use Modify Reading to add or subtract the offset you noted so the display sits at 0 at atmosphere. If it was reading high, subtract that amount; if it was reading low, add it.

  4. Re-upload the design

    Upload the design to the gauge. The boost reading is now calibrated to your local atmospheric pressure.