hoverbot

Hoverboard + Raspberry Pi

mounting from pi to dev machine

sudo mount.cifs //loki.local/hoverbot /home/dave/loki -o user=dave,uid=$(id -u),gid=$(id -g)

TODO

hoverboard's responsibilities:

reporting current state - battery, temperature, wheel speeds
adjust speed to target speed, but in such a way that the transition is smooth
safely slow down and stop if there's no msg from the app
power on/off, including auto poweroff if no activity for awhile

app's responsibilities:

receive inputs from joystick
send target speeds for each wheel to hoverboard
read status data from hoverboard and shutdown on low power or high temp or whatever
figure out and impose safety limits: top wheel speeds, top opposite wheel speeds, acceleration rates, turning rates

msg TO hoverboard: 16b msgID (a counter, so we can detect skipped) 8b cmd - the command defines the length payload - maybe it's fixed sized?

TO commands:

heartbeat, just a way to say "keep going". payload:null
poweroff - stop listening for new data, set speed goal=0, and when reached, power off. payload: null
echomode. payload: on or off. maybe an echo debug mode where all it does is send back ACKs?
turn on/off various debug flags/values. payload: 1Bknob num, 2B:value
set max acceleration. payload: max pwm diff in... a second maybe?
set max speed. payload: max pwm value perhaps?
set max turn rate - maybe max wheel differential. payload: 2B int max diff
set target speed for each wheel. payload: 2B per wheel

msg FROM hoverboard: 16b msgID (a counter, so we can detect skipped) 8b cmd - the command defines the length payload - maybe it's fixed sized (but not necessarily the same as the IN msg size)

FROM commands:

startup / hello msg
unknown msg
heartbeat. just some stats on current speed, voltage, power draw, missed messages, speed goal, powering down or not
ACK any set commands?
auto powerdown w/ reason ID

main: all the init stuff set state = running # running, powerdown, echo speedL,R=0 speedGoalL,R=0 maxAccel = X maxTurn = X haveMsg = false trigger interrupt listener send a version / hello msg loop: sleep a little if state == echo: if haveMsg: loopsWithoutMsg = 0 if msg == echo and payload=off state = running else: echo the msg back trigger interrupt listener to start again else: need to do same no-msg countdown

    if state == running:
        if battery is too low:
            state = powerdown
            speedGoalL,R=0
            send auto-powerdown msg, reason=low battery
        if haveMsg:
            loopsWithoutMsg = 0
            make a note of any skipped msgs
            haveMsg = false
            if msg == heartbeat:
                pass
            elif msg == poweroff:
                state = powerdown
                speedGoalL,R=0
                send a powerdown msg, reason=host initiated
            elif msg == echomode:
                if payload == on:
                    state = echo
            #elif msg == set debug knob <-- implement this once we have a use case
            elif msg == set max accel
                set
            elif msg == set max speed
                set
            elif msg == set max turnrate
                set
            elif msg == set speed goal
                set
            else:
                send unknown msg msg

            trigger interrupt listener to start again
        else: # no msg ready
            loopsWithoutMsg++
            if loopsWithoutMsg > TOO_MANY:
                state = powerdown
                speedGoalL,R=0
                maybe send a msg indicating auto-powerdown w/ reason=listen timeout

    if state == powerdown:
        if speedL,R==0
            break

    # TODO: adjust speeds to get closer to goals, but also apply limits

    # TODO: if enough time has elapsed since last heartbeat out, send a status msg out

# post-loop
beep
poweroff

on interrupt: haveMsg = true

dfb/hoverbot

hoverbot

mounting from pi to dev machine

TODO