LUA Serial terminal success

[Art]

Hi Guys,
I have made what I beleive to be a suitable interface for the PSP serial
port with a pic 16F84A running at 4MHz producing serial data at 2400 baud.

I have altered the serial terminal application to make it run faster by
removing the echo, and removing the check for 60th cycle (produces the
dots on the screen to tell you the program is still running).

Code: Select all

terminal = Image.createEmpty(480, 272)

function scroll(image, dx, dy)
	new = Image.createEmpty(image:width(), image:height())
	new:blit(dx, dy, image)
	return new
end

function printTerminal(text)
	for i = 1, string.len(text) do
		char = string.sub(text, i, i)
		if char == "\n" then
			terminalY = terminalY + 1
			terminalX = 0
		else
			terminal:print(terminalX * 8, terminalY * 8, char, green)
			terminalX = terminalX + 1
			if terminalX >= 60 then
				terminalX = 0
				terminalY = terminalY + 1
			end
		end
		if terminalY >= 34 then
			terminalY = 33
			terminal = scroll(terminal, 0, -8)
		end
	end
end

function normalizeLinefeed(text)
	-- terminal programs like Hyperterminal sends just a \r for return key, convert it
	result = ""
	for i = 1, string.len(text) do
		char = string.sub(text, i, i)
		if char == "\r" then char = "\n" end
		result = result .. char
	end
	return result
end

printTerminal("initializing SIO...\n");
System.sioInit(2400)
infoString = "Rx @ 2400...\n"
printTerminal(infoString);
System.sioWrite(infoString)
ping = 0
while true do
	text = normalizeLinefeed(System.sioRead())
	printTerminal(text)
	screen:blit(0, 0, terminal, 0, 0, terminal:width(), terminal:height(), false)
	screen.waitVblankStart()
	screen:flip()
	if Controls.read():start() then 
break
end
end

The terminal is very slow. Even this version requires 15ms character
pacing (that's a full 15 milliseconds between each received character).
I beleive I can make a pic interface between a GPS mouse and the PSP,
receiving at 4800 baud, adding the character pacing, and retransmitting
to the PSP at 2400 baud.
An application like a GPS front end isn't going to have much time to
update the screen to get back to the serial routine for the next seconds
data. There might be the possibility of just updating the data every couple
of seconds.
Cheers, Art.

[Art]

and of course, the code for the pic 16F84A that is to be clocked at 4MHz to
achieve 2400 baud with 15ms character pacing.
The program is compiled with Microengineering Labs Pic BASIC Pro,
and outputs infinite test messages:
" Variable = 0 Variable = 1 Variable = 3.... and so on"
This is what I have reliably achieved on the PSP screen.

The pic program can also drive a 3x7 segment LED display array so you
can view the test variable on LED screen, but it isn't required that any
displays be connected.

Connect the blue wire from your PSP remote controller plug to gnd of the pic circuit,
and the grey wire from the PSP remote via 470 Ohm resistor to port RB0 of the pic circuit

Code: Select all

'
''''''''''''''''''''''''''''''''''''''''''''''
' Multiplexed 3x7 Segment LED Display Driver / PSP Serial port tester '
'                                            '
'         Art           '
''''''''''''''''''''''''''''''''''''''''''''''
'
trisa = 0				'set all ports as outputs
trisb = 0				'
trisa.0 = 1				'now set individual inputs
trisa.4 = 1				'
trisb.0 = 1				'
'
OPTION_REG = %00100000			'put timer module in counting mode
'
include "modedefs.bas"
DEFINE CHAR_PACING 15000			'
'
delay var byte				'
D1 var byte				'display buffers
D2 var byte				'
D3 var byte				'
DB var byte				'display digit buffer
B1 var byte				'
B2 var byte				'
B3 var byte				'
B4 var byte				'
B5 var byte				'
B6 var byte				'
B7 var byte				'
B8 var byte				'
B9 var byte				'
B0 var byte				'
C2 var word				'
M1 var word
'
M1 = 0
@ goto _testA				'skip interrupt handler
'
cnt:
'
Three_dig:
'

DB = D1
low porta.2
gosub digit
high porta.2
DB = D2
low porta.3
gosub digit
high porta.3
DB = D3
low porta.1
gosub digit
high porta.1
return
'
digit:
@            MOVF    _DB      , W
@            SUBLW   0x00
@            BTFSS   STATUS    , Z
@            GOTO    _Label_0016
@            MOVLW   0x80
@            MOVWF   _DB
Label_0016:
@            MOVF    _DB      , W
@            SUBLW   0x01
@            BTFSS   STATUS    , Z
@            GOTO    _Label_0017
@            MOVLW   0xE6
@            MOVWF   _DB
Label_0017:
@            MOVF    _DB      , W
@            SUBLW   0x02
@            BTFSS   STATUS    , Z
@            GOTO    _Label_0018
@            MOVLW   0x48
@            MOVWF   _DB
Label_0018:
@            MOVF    _DB      , W
@            SUBLW   0x03
@            BTFSS   STATUS    , Z
@            GOTO    _Label_0019
@            MOVLW   0x42
@            MOVWF   _DB
Label_0019:
@            MOVF    _DB      , W
@            SUBLW   0x04
@            BTFSS   STATUS    , Z
@            GOTO    _Label_001A
@            MOVLW   0x26
@            MOVWF   _DB
Label_001A:
@            MOVF    _DB      , W
@            SUBLW   0x05
@            BTFSS   STATUS    , Z
@            GOTO    _Label_001B
@            MOVLW   0x12
@            MOVWF   _DB
Label_001B:
@            MOVF    _DB      , W
@            SUBLW   0x06
@            BTFSS   STATUS    , Z
@            GOTO    _Label_001C
@            MOVLW   0x10
@            MOVWF   _DB
Label_001C:
@            MOVF    _DB      , W
@            SUBLW   0x07
@            BTFSS   STATUS    , Z
@            GOTO    _Label_001D
@            MOVLW   0xC6
@            MOVWF   _DB
Label_001D:
@            MOVF    _DB      , W
@            SUBLW   0x08
@            BTFSS   STATUS    , Z
@            GOTO    _Label_001E
@            CLRF    _DB
Label_001E:
@            MOVF    _DB      , W
@            SUBLW   0x09
@            BTFSS   STATUS    , Z
@            GOTO    _Label_001F
@            MOVLW   0x02
@            MOVWF   _DB
Label_001F:
portb = DB
'
pauseus 2200
portb = $FF
'
'

'
return
'
'***************************************************************************************************************
'
testA:
delay = 5
C2 = 0
'
test:
low porta.2
gosub segments
high porta.2
low porta.3
gosub segments
high porta.3
low porta.1
gosub segments
high porta.1
low porta.4
gosub segments
high porta.4
delay = delay - 1
IF delay = 255 THEN
INTCON = %10010000			'turn on interrupt when display test is done
goto start
ENDIF
goto test
segments:
high portb.1
pause delay
high portb.2
pause delay
high portb.3
pause delay
high portb.4
pause delay
high portb.5
pause delay
high portb.6
pause delay
high portb.7
pause delay
low portb.1
pause delay
low portb.2
pause delay
low portb.3
pause delay
low portb.4
pause delay
low portb.5
pause delay
low portb.6
pause delay
low portb.7
pause delay
return
'
'***************************************************************************************************************
'
start:
D1 = 0
D2 = 0
D3 = 0
'
FOR delay = 0 TO 90			'Hold 000 on display at startup
gosub Three_dig
NEXT delay
'goto cnt
'
'***************************************************************************************************************
'

Dog:

M1 = M1 + 1

D1 = M1 DIG 0				'
D2 = M1 DIG 1				'
D3 = M1 DIG 2				'

FOR delay = 0 TO 75			'Hold display
gosub Three_dig
NEXT delay


serout portb.0,OT2400,[" Variable = ",#M1]    ' 2400 baud true

goto Dog				'


disp:
D1 = C2 DIG 0				'
D2 = C2 DIG 1				'
D3 = C2 DIG 2				'

FOR delay = 0 TO 100			'Hold display
gosub Three_dig
NEXT delay
return

And here's the hex code so you don't need to own the compiler to test the circuit:

Code: Select all

:10000000AC28910190009F1727308F0010301420EA
:1000100003308F00E83014208F01643014208F01EA
:100020000A30142010081F288E0011088D001008B7
:100030008C008B200C08031D9F139F1B0800303E73
:100040009200220884000930930003103020920CA3
:10005000930B2628031430203A308D0098306D28F9
:1000600084139F1D3F28000820041F1D20068000C8
:10007000841700082004031C200680004A2800087A
:100080002004031C20061F19200680008417200965
:1000900080054A281F0D06398C0053208D008C0ADC
:1000A000532000006D2800308A000C0882070134BC
:1000B00075340334153400343C340C34D9348F0196
:1000C0008E00FF308E07031C8F07031CA728033008
:1000D0008D00DF306D2061288D01E83E8C008D0998
:1000E000FC30031C76288C07031873288C076400E7
:1000F0008D0F73280C187C288C1C80280000802809
:100100000800013E93000A308E008F018B20930B74
:1001100086281008080091019001103092000D0D02
:10012000900D910D0E0890020F08031C0F0F910205
:100130000318A1280E0890070F0803180F0F910746
:1001400003108C0D8D0D920B8F280C08A72883139C
:1001500003138312640008008316850186010514C9
:1001600005160614203081008312A601A7011E295E
:100170003208B5000511831605118312DA20051522
:100180008316051183123308B50085118316851176
:100190008312DA2085158316851183123408B50081
:1001A0008510831685108312DA2085148316851036
:1001B000831208003508003C031DE0288030B5009C
:1001C0003508013C031DE628E630B5003508023C41
:1001D000031DEC284830B5003508033C031DF22808
:1001E0004230B5003508043C031DF8282630B50020
:1001F0003508053C031DFE281230B5003508063CC5
:10020000031D04291030B5003508073C031D0A29D9
:10021000C630B5003508083C031D0F29B501350867
:10022000093C031D15290230B50035088600083049
:100230008D0098306D20FF30860008000530B60034
:10024000A401A5010511831605118312502105157E
:10025000831605118312851183168511831250218F
:1002600085158316851183128510831685108312D8
:1002700050218514831685108312051283160512EA
:10028000831250210516831605128312B6036400EB
:100290003608FF3C031D4F2990308B00A5292229E9
:1002A000861483168610831236085F20061583167F
:1002B0000611831236085F20861583168611831275
:1002C00036085F20061683160612831236085F2052
:1002D000861683168612831236085F200617831649
:1002E0000613831236085F2086178316861383123F
:1002F00036085F20861083168610831236085F202A
:10030000061183160611831236085F2086118316A4
:100310008611831236085F20061283160612831296
:1003200036085F20861283168612831236085F20F5
:10033000061383160613831236085F20861383166E
:100340008613831236085F200800B201B301B4019E
:10035000B60164005B3036020318B129B820B60F2D
:10036000A929A60A0319A70A26088C0027088D00C8
:1003700000308120B20026088C0027088D00013053
:100380008120B30026088C0027088D0002308120D0
:10039000B400B60164004C3036020318D229B820EC
:1003A000B60FCA290630A2000130A00008309F0015
:1003B0002030202056302020613020207230202034
:1003C0006930202061302020623020206C302020D5
:1003D00065302020203020203D302020203020207B
:1003E0002708910026080220B12924088C0025083E
:1003F0008D0000308120B20024088C0025088D007B
:1004000001308120B30024088C0025088D000230C3
:100410008120B400B6016400653036020318132A47
:08042000B820B60F0B2A0800FA
:02400E00F53F7C
:00000001FF

I am releasing this because I intend to take it further.
I will shortly biuld a smaller circuit without the display
for the purpose of serial level/timing conversion between the
PSP and other devices (particularly GPS).
Cheers, Art.



Cheers, Art.

[Master Inuyasha]

what is the point of this?

[Art]

In the long run, hopefully a way to get data from a GPS mouse into the PSP
so myself or someone else can get started on a GPS front end.
I hope to get a moving 'Google Earth image' compatible GPS up & running.

If you have no way of programming a pic, and putting it into a suitable
circuit, this isn't for you.
Art.

[Master Inuyasha]

oh know i see, i never knew you could do that on the PSP. Way to go!!! Good luck.

[Zenurb]

I'm interested in this, but I've got no hardware available to me, being as I am a poor student :P

Perhaps you could post circuit diagrams / lists of equipment you used to help other people in future.

[Art]

It doesn't look to be possible to post pictures here.
I would probably like to wait till I have something more developed.

After some more testing with the serial terminal program, I don't think it's
ever going to be fast ehought to receive data directly from a GPS mouse
even at 4800 baud without a chip in between to buffer and retransmit the
signal at slower rates.

I might even look at some 'pre-processing' of the GPS data so that only
minimal bytes need be send to the PSP.
Art.

[JoshDB]

If you could develop a keyboard for the psp...

Good god man, you'd be loved.

[Art]

a serial keyboard would be very simple to make, but a DIY one
might not look pretty.
People would need to biuld the hardware themselves,
and write PSP software to support it.
I'm not sure it would catch on being a hardware project.

I have a good schematic drawing for the circuit described above.
Does anyone have somewhere to host it (and another image).
and perhaps possible future hardware projects?
Cheers, Art.

[aldebaran]

Can you post me the drawings of your rs 232 interface? I'll try to develop a serial keyboard, too. Thanks.

[JoshDB]

I have unlimited space/bandwidth on my server.

Anything you want, just PM me.

[Art]

If you could develop a keyboard for the psp...

Good god man, you'd be loved.

I'll try to develop a serial keyboard, too. Thanks.

With the new IRDA support in LUAplayer, it won't be long before someone
is using an IRDA keyboard for mobile phones with the PSP.
I don't think there would be any stuffing around with hardware involved at all.

My GPS front end program is hosted at a couple of sites now, and linked
to from a couple more, so no need to have it hosted again, and try to
update them all at once when I have new versions to upload.
Art.

[Shine]

After some more testing with the serial terminal program, I don't think it's
ever going to be fast ehought to receive data directly from a GPS mouse
even at 4800 baud without a chip in between to buffer and retransmit the
signal at slower rates.

Thanks for discovering this problem, looks like Lua Player sucks :-)

The reason is that the SIO data is not buffered in some large system buffer, as I wrongly assumed in some other posting, but only the hardware FIFO is used. I don't know the size of it, but normally it is something like 8 or 16 bytes. So if you query only every 1/60 seconds (every vsync), you read the buffer every 16 ms, but at 4800 baud the hardware receives about 10 bytes in 16 ms, which might be too much for the hardware buffer.

A (bad) solution would be to use System.sleep and polling instead of using vsync. A better solution would be to improve the Lua Player SIO driver to use interrupt based reading (if possible by the hardware) with larger buffers and synchronized access.