You are viewing sappa

Mar. 16th, 2007 @ 12:40 pm UV LED lightbox from old flatbed scanner




At first, I disassembled HP ScanJet 5c and found two boards mounted on the scanner chassis. The first one, with power supply and stepper motor driver seemd to be usable in the lightbox. The second one with SCSI logic and controller has been dropped away and replaced by my own controller board. 3 plastic slide blocks has been unscrewed from unmounted carriage (with CCD, optics and lamp).



These slide blocks screwed to the new carriage:



I screwed one optical sensor (AKA photo interrupter) to chassis, it should be triggered when crarriage moved to the start position.

On this photo:
1. stepper motor
2. optical sensor
3. LEDs
4. plastic slider blocks
5. piece of tin for optical sensor obturation



On this photo you can see how carriage connected to the belt.



LEDs board schematics



Resistors - 200 Ohm (SMD type 1206), LEDs - Kingbright L-7113UVC.

LEDs PCB



Controller board schematics



SV1-1 to optical sensor LED anode (+)
SV1-2 to optical sensor LED cathode (-)
SV1-3 to optical sensor phototransistor collector
SV1-4 to optical sensor phototransistor emitter

Optical sensors TCST1103, TCST2103 (Vishay), KTIR0311S, KTIR0411S (Kingbright), etc.

SV2-1 to LEDs board +
SV2-2 to LEDs board -

SV3-1 to green LED (front panel) anode (+)
SV3-2 to green LED (front panel) cathode (-)
SV3-3 to button (front panel)
SV3-4 to button (front panel)

Plug ribbon cable from power supply board to connector CON1.

Controller PCB



LEDs PCB 600dpi

Controller PCB 600dpi

Firmware for PIC12F629/PIC12F675

Source code

// TBD: Description

About this Entry
pleased
[User Picture Icon]
From:sab123
Date:March 16th, 2007 03:28 pm (UTC)
(Permanent Link)
Эта, делает-то оно что?
(Frozen) (Thread)
[User Picture Icon]
From:sappa
Date:March 16th, 2007 04:48 pm (UTC)
(Permanent Link)
Печатные платы с нанесеным фоторезистом засвечивает. Но это еще не готовая статья, просто за один присест мне не понаписать...
(Frozen) (Parent) (Thread)
[User Picture Icon]
From:sab123
Date:March 16th, 2007 10:08 pm (UTC)
(Permanent Link)
А почему нельзя было употребить сканер как есть? Он, поди, и так при нажатии кнопки двигал бы лампочку? Или нет?

Кстати, а что, светодиоды действительно ультрафиолетовые?
(Frozen) (Parent) (Thread) (Expand)
From:(Anonymous)
Date:September 15th, 2009 01:52 am (UTC)

Keen interest to develop my own UV flatbed scanner

(Permanent Link)
Hi Sappa,

Have you tried using the latest flatbed scanner besides the HP ScanJet, which is obselete?

If so, hope you can advise me which brands and models. I am interested to try it myself. But due to budget contraint, I have to ensure that I get hold of the correct scanner.

Thank you very much & look forward to hear your advice soon.

Warm regards
Chester Oh
(Frozen) (Parent) (Thread)
[User Picture Icon]
From:sappa
Date:September 15th, 2009 12:14 pm (UTC)

Re: Keen interest to develop my own UV flatbed scanner

(Permanent Link)
Hi!

I didn't try to repeat this UV lightbox using latest scanner models and I am not sure that it is still reasonable to make such overcomplicated device today, when you can buy 500 UV LED's for $30-$35 and make simple big grid without any mechanics. In such case you can use any flatbed scanner you have because the only you need is a box and a glass.
(Frozen) (Parent) (Thread)
From:(Anonymous)
Date:March 18th, 2007 09:05 pm (UTC)

SCHEMATICS

(Permanent Link)
Hi Sappa,

Tx for all the effort you have made to document your project. I am sure that there are numerous people disassembling their old scanners at this very moment!!

Regards
Conroy
(Frozen) (Thread)
From:conroydp
Date:March 19th, 2007 06:24 am (UTC)

CONNECTIONS ON CON1

(Permanent Link)
Hi Sappa,

Unfortunately, I am using a different type of scanner and would appreciate it if you could assist by providing pins layouts for the 14pin ribbon cable.

I have 2 more questions:
a) are you controlling the speed of the stepper motor via the PIC?
b) what are the 2 switches used for?

Regards
Conroy
(Frozen) (Thread)
[User Picture Icon]
From:sappa
Date:March 19th, 2007 10:10 am (UTC)

Re: CONNECTIONS ON CON1

(Permanent Link)
Yes, I control every step (even every half-step) via the PIC. Power supply scanner board has PBL3775 stepper motor driver chip. According to datasheet this driver controlled by 2 wires (full step mode), 4 wires (half step mode) or 6 wires (modified half step mode). I use the last one because it provide most smooth movement. On my controller board schematics you can see wire names (close to CON1 pins) that correspond to PBL3775 input lines. Other scanners may use different stepper motor drivers.
(Frozen) (Parent) (Thread)
From:conroydp
Date:March 19th, 2007 02:20 pm (UTC)

Re: CONNECTIONS ON CON1

(Permanent Link)
Hi Sappa,

Unfortunately, I do not recognise (or are able to find datasheets) on most of the IC's on the board.

The only 3 IC's I could find info on are the ES50299 (10 bit A/D converter) and the 74HC4066D (Quad bilateral switch) and a TD62003 (7 ch darlington sink driver). It does not appear to be one of these.

What I did to drive the unipolar motor is build a stpper motor driver taken from the KITSRUS site. http://www.kitsrus.com/pdf/k179.pdf

The kit has 3 external switches:
- to determine whether the pulses will be generated external or internal to the board
- to determine the direction of the motor
- external link for the STEP of the motor

I completed and tested the circuit yesterday afternoon and it seems able to control the motor at a rate of 1.5 cm/min to max speed.

I guess that it would be possible to integrate this kit as a stepper motor driver into your design.

My direct mail address is conroydp@bcx.co.za if you prefer to send mail to me directly.

Tx
Conroy
(Frozen) (Parent) (Thread) (Expand)
[User Picture Icon]
From:sappa
Date:March 19th, 2007 10:14 am (UTC)

Re: CONNECTIONS ON CON1

(Permanent Link)
BTW, can you find what kind of stepper motor driver chip used in your scanner?
(Frozen) (Parent) (Thread)
From:conroydp
Date:March 25th, 2007 08:57 am (UTC)

Re: CONNECTIONS ON CON1

(Permanent Link)
Hi Sappa,

Yes, my problems I experiencing during "power-on" have been resolved.

a) should I add the follwing code to my .asm file?

init
bsf STATUS, RP0 ; Set bank 1
call 0x3FF ; Get calibration constant stored at 0x3FF
movwf OSCCAL ; write it into OSCCAL

b) I noticed that the scanner bed does not move the full length of the A4 before returning to resting position. Where do I incease the disctance travelled? Would it be by changing some of the following values:

; Maximum movement in forward direction (carriage should not stall)
FMAXSTEPS_HI EQU 0x15
FMAXSTEPS_LO EQU 0x80

; 0x10000 - maximum movement in reverse direction (protect if optical sensor failed)
RMAXSTEPS_HI EQU 0xE8
RMAXSTEPS_LO EQU 0x00

Regards
Conroy

(Frozen) (Parent) (Thread)
[User Picture Icon]
From:sappa
Date:March 25th, 2007 11:15 am (UTC)

Re: CONNECTIONS ON CON1

(Permanent Link)
a) this code ALREADY in your .asm file although without such detailed comments.
b) yes, increase FMAXSTEPS_HI/FMAXSTEPS_LO value for desired movement limit during exposure.

RMAXSTEPS_HI/RMAXSTEPS_LO usually should be a bit less than 0x10000 - (FMAXSTEPS_HI*256 + FMAXSTEPS_LO). (decreasing this value will increase maximum movement during calibration. Usually these values are unused, but it is protection if optical sensor does not work properly).
(Frozen) (Parent) (Thread) (Expand)
[User Picture Icon]
From:lavrinenko
Date:March 19th, 2007 09:04 am (UTC)
(Permanent Link)
снимаю шляпу!
(Frozen) (Thread)
From:(Anonymous)
Date:March 19th, 2007 02:03 pm (UTC)
(Permanent Link)
У, круто.
(Frozen) (Thread)
From:conroydp
Date:April 18th, 2007 07:38 pm (UTC)

DRIVER FOR BIPOLAR STEPPER MOTOR

(Permanent Link)
Hi Sapa,

Hope you have been well since our last conversation. My latest project is to build a desktop CNC router/milling machine.

Seeing that the circuit you provided is working so well, I was wondering whether you had previously designed or built a driver circuit for a bipolar stepper motor that accepts the step and direction input from a PC parallel port.

The circuit I am after also require inputs for limit switches. Maybe it is also capable of micro-stepping? (not a requirement in my case)

Regards
Conroy
(Frozen) (Thread)
[User Picture Icon]
From:sappa
Date:April 19th, 2007 01:32 pm (UTC)

Re: DRIVER FOR BIPOLAR STEPPER MOTOR

(Permanent Link)
Hi Conroy,

I never designed machines with stepper motor controlled by LPT,
but I don't see any problem there. LPT is usual CMOS level I/O
lines and you can use any stepper motor driver controlled by
CMOS level signals. You may look on http://www.bright.net/~agarb/STMD/AVR_STMD.html
for basic idea. Or even build your own driver based on 2
full bridges (8 transistors) or half-bridges. It depends on
power supply and motor you plan to use in this machine.
(Frozen) (Parent) (Thread)
From:(Anonymous)
Date:June 14th, 2007 12:12 pm (UTC)
(Permanent Link)
Hi, I'm trying to replicate your device, and have acquired a slightly newer version of the hp scanner your using, however it uses the UND2916b dual full-bridge PWM motor driver.(power/stepper driver board still has the 14pin ribbon cable you reference) Two questions, one do I need to modify the hex or hardware to support this chip, two do you think that it is a pin for pin comparable on the ribbon cable side?
(Frozen) (Thread)
[User Picture Icon]
From:sappa
Date:June 14th, 2007 01:15 pm (UTC)
(Permanent Link)
Hi,
I have never seen HP power/stepper driver board based on UDN2916B, but this driver can be used in a variety of ways. Please, trace all wires from this chip to the ribbon cable connector and show me this diagram. In this case I would be able to help you.
(Frozen) (Parent) (Thread)
From:(Anonymous)
Date:June 14th, 2007 10:47 pm (UTC)
(Permanent Link)
Heres where I'm at, I(12)-. .-vref2
vref1-. .-phase2
phase1-. .-I(11)
GND-. .-GND
?-. .-?
GND-. .-GND
(pin1) ?-. .-?

?= not connect to motor driver
Does this help any? if not, later i can sit down and reverse engineer the driver section of the board
(Frozen) (Parent) (Thread)
[User Picture Icon]
From:sappa
Date:June 14th, 2007 11:55 pm (UTC)
(Permanent Link)
Looks very similar to previous pinout (based on PBL3775) and digital current control is not used. But anyway, trace at least I(01) and I(02). I suppose these lines either connected to I(11) and I(12) respectively or pulled up to power, but it's better to be sure.
(Frozen) (Parent) (Thread) (Expand)
(no subject) - (Anonymous) - Expand
From:(Anonymous)
Date:October 8th, 2007 09:56 pm (UTC)

scanjet 5p

(Permanent Link)
Hi, there's a Scanjet 5P for sale..do you think it's similar to yours?
(Frozen) (Thread)
[User Picture Icon]
From:sappa
Date:October 8th, 2007 10:22 pm (UTC)

Re: scanjet 5p

(Permanent Link)
I am not absolutely sure, but it looks similar to my Scanjet 5c. The same body, and the same _visible_ internals. Even it has different CCD sensor and/or controller board, these components are not used it my UV light box. So, most probably 5p can be used without any changes in my schematic.
(Frozen) (Parent) (Thread)
From:(Anonymous)
Date:November 14th, 2009 02:28 pm (UTC)

Simply Awesome

(Permanent Link)
I had been researching pcb exposure boxes for at least 24 hours when I stumbled across your post at hacked gadgets.com. I said to myself, "Self, that is a ScanJet Scanner!, and there is a broken ScanJet in the basement collecting dust." Seriously, I like the scanner technique. I think it is an awesome idea and personally prefer it to the stable grid idea. In fact, now I am thinking of buying another ScanJet on ebay, just so I can put one on top of the other and do two-sided pcbs. Thanks for the information.

Bruce
(Frozen) (Thread)
From:khalid86
Date:November 24th, 2010 08:22 am (UTC)

LED Directory

(Permanent Link)
This is a good use of LED I must say.

LED Directory
(Frozen) (Thread)
From:madelinaob
Date:June 8th, 2011 03:31 pm (UTC)

Шикарный блог

(Permanent Link)
Ура!, тот кто писал ништяк написал!
(Frozen) (Thread)