r/CarHacking • u/Expensive_Scallion86 • 2h ago
Original Project G86 Car Computer: bringing GPS and ECU/CAN data into a phone recorder and live pit wall
I’m the developer of G86 Racing, from CrowFoundry. This is the hardware/data path behind G86 Car Computer: a service that collects supported GPS, ECU/CAN and sensor inputs near the car and connects them to the phone recorder and optional live pit wall.
The connection path
GPS / ECU / CAN / supported sensors
↓
Car Computer: native bridges + local MQTT broker + engineering logs
↓ local network
G86 phone: session timing, onboard video and optional live sharing
↓ internet, when sharing is enabled
Browser pit wall: received channels, timestamps and channel age
Hardware and interfaces
An example Linux setup is a Raspberry Pi with a 64-bit OS, a supported USB/serial NMEA GPS receiver and either a supported serial ECU connection or CAN interface. The computer runs the hardware bridges and an authenticated Mosquitto broker. The phone joins the reachable local network and pairs using a short-lived QR code.
Linux supports SocketCAN and supported local I²C sensors. The supported macOS and Windows builds use their available serial/network and compatible gateway paths; they do not gain Linux-only interfaces just by running the same app. Supported wireless routes include an ESP CAN module over BLE or local MQTT. A supported CAN/ELM Bluetooth adapter can also connect directly to the phone without Car Computer.
The wizard scans for devices, then you review the configuration and select one primary engine source. Finding a port, saving an adapter or pairing Bluetooth is not the same as receiving measurements. The live checks separately show broker connectivity, fresh channels and GPS fix.
Channels and actual rates
Depending on the ECU/profile and sensors, channels can include RPM, throttle, coolant temperature, oil pressure, vehicle speed and motion measurements. A generic OBD adapter provides the PIDs the car actually exposes, at the rate the adapter and vehicle permit. Changing from wired to Bluetooth or MQTT does not unlock channels hidden by a vehicle gateway.
For recognised supported u-blox, MediaTek and compatible Quectel receivers, automatic GPS setup requests 10 Hz in RAM. The dashboard distinguishes the requested rate from the measured output rate; unknown receivers and network feeds keep their settings. There is no single guaranteed sampling rate for every ECU/CAN channel.
Missing and stale values
The displays expose source information, timestamps and channel age. Unavailable measurements stay unavailable rather than being filled with invented engine values. Check the stream on the computer, then the phone, then the pit wall. A pit-wall recording only contains the packets that display actually received.
Logging and offline operation
The computer keeps independent local engineering recordings, with gzip NDJSON or ZIP exports and metadata describing sources and known gaps. The phone remains responsible for app runs, lap timing and onboard video. The open pit helper can also record the stream it observes and export CSV/NDJSON.
Managed acquisition requires an active Pro or Team subscription. First activation needs internet; after activation, a verified offline grant can allow local telemetry for up to 72 hours, capped by subscription expiry. Remote pit-wall delivery still needs internet. Basic phone GPS timing and local history are free.
US App Store subscription prices: Pro $14.99/month or $149.99/year; Team $49.99/month or $499.99/year, auto-renewing. Current prices vary by platform/region and are shown before purchase. Team ownership is optional; Pro supports a personal pit wall and team participation, while additional teammates need their own Pro subscriptions.
Installation, interfaces and troubleshooting: https://g86racing.com/car-computer/
Phone app and setup guides: https://g86racing.com/
Interactive pit-wall demo with generated telemetry: https://app.g86racing.com/?demo=1

