popufare/busunit/paddlemgr

paddlemgr

This is a program to manage "paddles", the name for bus trips and bus routes.

This program is in charge of taking "advance bus stop" requests as well as monitoring GPS messages and system time to advance the route appropriately.

Building

$ ./buildit_native.sh

Program Overview

The paddlemgr program manages "paddles", including bus stops and advances due to driver input or from GPS updates.

On driver login, the driver will select a paddle which will send a message to the paddlemgr through the IPC to load a paddle. On successful paddle load, the paddlemgr will store the paddle in memory for use.

The GPS updates come in through the IPC hub and is processed to determine if a stop rollover should occur. If the stop time, as recorded in the paddle file, is within some time window (currently set to 10mins) and the current position is within a distance window of the stop (currently set to 60m), the stop is advanced.

The drive can manually advance stops by pressing the 'NXT' or 'PRV' buttons from the driver UI which will send messages through the IPC to the paddlemgr to advance the stop. Regardless of whether a driver signal for 'NXT', 'PRV' or an automatic stop rollover has occured, the internal state of paddlemgr is updated to reflect the new stop and a message sent through the IPC to signal what the current stop is.

Inter Process Communication (IPC)

IPC Mailbox	Function
MAILBOX_GPS_STATUS	handle_gps_update
MAILBOX_STATUS_REQUEST	handle_status_req
MAILBOX_SET_PADDLE	handle_set_paddle_req
MAILBOX_NEXT_STOP	handle_next_req
MAILBOX_PREV_STOP	handle_prev_req

IPC Messages	Description
MAILBOX_PADDLE_ACK	Sent on receipt of paddle and successful paddle load (through load_paddle)
MAILBOX_STOP_STATUS	Sent on receipt of a "status request" messages or on stop change (through send_status_update)

Quick Reference

Value	Description
CONFIG_FILE_PATH	Default location of where to look for config files (paddles etc.). Default to /home/bus/config.
ROLLOVER_TIME_WINDOW	Window to consider stop if it's within +/- the time window. Default to 600 seconds (10min).
ROLLOVER_DISTANCE	Distance window to consider a stop rollover if it's within +/- the range. Default to 60.0f (in DMM format).

See the Paddle Format documentation for the format of the paddle file.