bitbrewers/lappy repository overview

⁠Lappy

Lappy is a backend for AMB TranX-2 timing system.

⁠Features

• Read passing and noise events from serial device
• Store passing events in sqlite database with race id
• Publish noise and passing events as server-sent events⁠
• Associate metadata with race records
• Systemd files
• HTTP API
  • Starting and stopping recoring and publishing passing events
  • Subscribe to SSE
  • CRUD for metadata like drivers names and car numbers
  • Fetch records per race
  • Fetch top records

⁠Configuration

Required environment variables:

• LOG_LEVEL : debug|info|error
• DSN : sqlite3 DSN eg. file:test.db
• LISTEN_ADDR : address to listen eg. 0.0.0.0:8000
• SERIAL_PORT : path to serial device eg. /dev/usbTTY11

⁠Running with docker using local serial device

Create tunnel with socat

socat -d -d PTY,raw,echo=0 PTY,raw,echo=0
2018/09/12 13:33:11 socat[31301] N PTY is /dev/pts/4
2018/09/12 13:33:11 socat[31301] N PTY is /dev/pts/5
2018/09/12 13:33:11 socat[31301] N starting data transfer loop with FDs [5,5] and [7,7]

Start container and mount /dev/pts to access just created /dev/pts/4

docker run --rm -it \
    -v /dev/pts:/dev/pts \
    -p 8000:8000 \
    -e LOG_LEVEL='debug' \
    -e DSN='file:test.db' \
    -e LISTEN_ADDR=':8000' \
    -e SERIAL_PORT='/dev/pts/4' \
    bitbrewers/lappy:latest

Install simulator and start it to create trafic

go get github.com/bitbrewers/tranx2/cmd/tranx2sim
tranx2sim -i 10000 -t 5 -j 2000 > /dev/pts/5

⁠Running locally with simulator

Instructions for basic linux setup

⁠Requirements

• socat
• go
• tranx2sim

⁠Steps

1. Install socat and go from repos
2. Install tranx2sim: go get github.com/bitbrewers/tranx2/cmd/tranx2sim
3. Use socat for piping serial data: socat PTY,raw,link=ttyS10,echo=0 PTY,raw,link=ttyS11,echo=0
4. Start simulator tranx2sim -i 10000 -t 5 -j 2000 > ./ttyS10
5. Start lappy with SERIAL_PORT=./ttyS11

⁠Development

Clone repo and run make dev. For more check the Makefile.