RacingtoMars
Member
Hi,
We have a Raspberry Pi employed as a media player, but like to isolate everything from the mains at night time. There are already plenty of devices and designs that will shut the Pi down and isolate it from the 5V power supply, but I want something that completely and utterly shuts off! We often shutdown the media player and forget to switch it off at the wall socket.
And besides, I needed a PICAXE project
The 'interrupt' tells the Pi to shut down and relies on someone else's Python code running on the Pi. In this case the PICAXE merely 'passes on the message' and could be deemed superfluous. Shutting down the Pi from its menu will now notify the PICAXE when one of the GPIO ports (GPIO 14, physical pin 08) drops in voltage and the PICAXE will shut off the relay. The downside to this set-up is that a dual-pole momentary action button is required to switch on the mains to the rig, at which point the relay latches on.
I haven't had much experience coding, so I would welcome any feedback, thanks!
Craig.
We have a Raspberry Pi employed as a media player, but like to isolate everything from the mains at night time. There are already plenty of devices and designs that will shut the Pi down and isolate it from the 5V power supply, but I want something that completely and utterly shuts off! We often shutdown the media player and forget to switch it off at the wall socket.
And besides, I needed a PICAXE project
The 'interrupt' tells the Pi to shut down and relies on someone else's Python code running on the Pi. In this case the PICAXE merely 'passes on the message' and could be deemed superfluous. Shutting down the Pi from its menu will now notify the PICAXE when one of the GPIO ports (GPIO 14, physical pin 08) drops in voltage and the PICAXE will shut off the relay. The downside to this set-up is that a dual-pole momentary action button is required to switch on the mains to the rig, at which point the relay latches on.
I haven't had much experience coding, so I would welcome any feedback, thanks!
Craig.
Code:
#picaxe 14M2 ' specify processor
#rem
Not using interrupts because immediate action is not required.
There are also several 'if' statements and subroutines to determine the course of action.
For example, the reset sequence requires that the power is NOT switched off.
#endrem
symbol GPIO = pinC.3 ; connects to GPIO14 (phys pin #08) TXD0 to measure level
; *need a weak pull-down resistor on this connection (will need testing)
symbol RLY = B.1 ; o/p to the transistor to turn off the relay via transistor
symbol OFF_BTTN = C.4 ; initiate shut-down after 0.5s press with beep to confirm
symbol PIEZO = C.2 ; sound output
symbol RST_BTTN = C.1 ; if Pi is powered-down initiate re-boot, else shut-down first
symbol RSTPi = B.5 ; needs an o/p to ground GPIO03 (phys pin #5) SCL1 to reset Pi
; B.5 requires pull-UP
symbol PiGoOff = B.3 ; o/p to ground GPIO23 (phys pin #16) GPIO_GEN4 to interrupt Pi
; B.3 requires pull-UP
symbol LED = B.2 ; Power indication - necessary?
symbol statusLED = B.4 ; indicates the status checking
; want this to run ONCE at power-on!
tune PIEZO, 4, ($60,$67,$40,$65,$6A,$45,$67,$42,$47,$10) ;Arpeggio UP
pause 2000 ; wait for GPIO14 TXD0 to settle down
init: b2 = 0 : b3 = 0
main:
low led : low statusLED : high RSTPi ; ensure LEDs are back off after a return to main routine
; *** smarten up with a dirs mask?
do while GPIO = 1 ; loop checking GPIO level + button status
high led ; power LED on
button OFF_BTTN,1,255,0,b2,1,hold_off
; i/p ?, act hi, delX, no rep, b2-var, when = 1, goto sub
button RST_BTTN,1,255,0,b3,1,hold_rst
if GPIO = 0 then exit ; if GPIO is low then the loop exits
loop ; end of loop
goto offPi ; this line executes when the loop is exited
; ***************************************************
hold_off: ; delay to time press-duration
let b4 = 1 ; reset counter variable b4 to 1
do while b4 < 5 AND pinC.4 = 1 ; begin a loop, ensures the button is held down
high statusLED ; statusLED on
pause 250 ; wait 150 ms
inc b4 ; increment the loop counter
low statusLED ; statusLED off
pause 250 ; wait 250 ms
loop ; end of loop
if pinC.4 = 0 then ; OFF button is NOT held down
goto main ; jump to main and its loop
else ; otherwise proceed
high statusLED ; statusLED on
tune PIEZO, 3,($50,$40) ; confirmation the button was held long enough
high PiGoOff ; *** tells the Pi to shut down..!
; *** Python code in Pi states GPIO23 (phys pin #16) GPIO_GEN4
goto offPi ; go to the power off subroutine - necessary??
; might require a delay
endif ; end the 'if' statement
; ***************************************************
hold_rst: ; delay to time press-duration
let b5 = 1 ; reset counter variable b5 to 1
do while b5 < 10 AND pinC.1 = 1 ; begin a loop
high statusLED ; statusLED on
pause 150 ; wait 150 ms
inc b5 ; increment the loop counter
low statusLED ; statusLED off
pause 150 ; wait 150 ms
loop ; ; the above code ensures the button is held down
if pinC.1 = 0 then ; reset button is NOT held down
goto main ; cancel & jump to main and its loop
else ; otherwise proceed
tune PIEZO, 3,($50,$40) ; confirmation the button was held long enough
low RSTPi ; o/p to ground GPIO03 (phys pin #5) SCL1 to reset Pi
let b6 = 1
Do until GPIO = 0 ; hold the process here until the Pi is off
if b6 => 20 then ;
goto main ; return to the main routine if nowt happens!
endif ; end the 'if' statement
high statusLED ; statusLED on
pause 250 ; wait 250 ms
low statusLED ; statusLED off
pause 125 ; wait 125 ms
inc b6 ; increment the variable
loop ; end of the loop
goto resetSequence ; jump to the reset routine
endif ; end the 'if' statement
; ******************************************************************
resetSequence: ; the reset routine!
pause 250 ; wait 250 ms ? necessary for debugging?
low RSTPi ; set RESET GPIO03 (phys pin #5) SCL1 to 0V
; Python code in the Pi states GPIO23 (phys pin #16) GPIO_GEN4
let b7 = 1 ; prime the variable
Do until GPIO = 1 ; hold the process here until the Pi is on
if b7 => 10 then ; 9 counter cycles
goto offPi ; a safety exit in case the reset fails
endif ; end the 'if' statement
high statusLED ; statusLED on
pause 50 ; wait 100 ms
low statusLED ; statusLED off
pause 400 ; wait 350 ms
inc b7 ; increment the counter
loop ; end of the loop statement
goto main ; return to the main routine
; *************************************************
offPi:
let b8 = 7 ; prime the variable - approx 7 secs delay
Do while GPIO = 0 AND b8 <> 0 ; loops when Pi has shutdown GPIO14 (phys pin #08)
low led ; power LED off
pause 500 ; wait 500 ms
high led ; power LED on
pause 500 ; wait 500 ms
b8 = b8 - 1 ; decrement the variable value
loop ; end loop
if GPIO <> 0 then ; check Pi power!
goto main ; need to double check the Pi is off!
else
tune PIEZO, 2, ($50,$4B,$49,$47,$45,$44,$42,$40,$27,$A0,$40,$50) ;scale DOWN
'tune PIEZO, 12,(7,9,5,37,192) 'plays Close Encounters tune
high RLY ; turns the relay off - THIS IS POWER OFF!!
pause 500 ; why? it's powered off!
endif ; end the 'if' statement
end
