The Beginning of the Assembly Language Tutorial

Today I gather some information regarding the quick way of learning assembly. This simply because the existed Assembly Programming book is too thick to teach a beginner in a short period of time. I found this tutorial by MAD is helpful so for those who are interested can download it here. This is the book that I make.

It is classified into four chapters for easy reference.
Chapter 1, Example1 (Examp1.asm),
Chapter 2,
Chapter 3,
Chapter 4, Example1 (Exbin.asm), Example2 (Exdec.asm), Example3 (Exvga.asm)

Yet another reason I collect all these is to help Mr Khow learning it the faster way rather than just simply copy the old program that I did three years ago.
As for the USB Board Tester board wiring, I did complete port A wiring yesterday, and today I plan to complete the other half of port B.

The Servo Motor PWM Generator Part 1

Today I do some study on the Pulse Width Modulation (PWM). There are few methods to generate the signals :
1-Analogue method,
2-Digital Method,
3-Discrete Method,
4-Onboard MicroController.
As for the beginning I think I will start with the digital method using the 2 input nor gates since this is the easiest to assemble. This is the circuit that I'm going to assemble after raya break.
This circuit board components requirement are listed below :
1-Variable resistor (potentiometer) 47kohm, 560kohm
2-Ceramic capacitor, 36nF, 100nF
3-Electrolytic capacitor, 10uF
4-2 input nor gates IC4001 with IC base
5-Discrete 1/4W resistor, 1 Mohm, 80.5 kohm, 46.3 kohm
6-PCB with 10mm stands
7-Connectors, 2 set of 2p for DC input and PWM output

I also continue doing the PCB for the USB Port Tester Board. Now all components are soldered already. However, the wiring I guess would only be completed by next month after raya break as well. Once the wiring is completed, it would looks something like this one.

As for Mr Khow, today he already started with the hardware programming using Borland Turbo C Compiler. To jumpstart, I advised him to simply rewrite the old 8255 working program and learn it while doing it hands on. Yet, to understand better for port assigning, I advised him to learn how to use the keyboard key first as it is easier to understand.

The Futaba S3003 DC Servo Motor

Today Mr Khow and I went to Vanguard in KL to buy 4 pieces of DC Servo Motor for RM280. Mr Robin from Vanguard and his friend Mr Wong did some demonstrations of their Bioloid robot stuff together with some ready made robotic hardwares. This is how the servos looks like.

As advised by Mr Wong this servo requires a (Pulse Width Modulation) PWM signal in order to be activated. The timing for PWM should be less than 100 ms. This means that I need to supply my PWM signal on my own- required a scope for signal checking. Yet another, he said the best way is to use the microprocessor to supply the signal of PWM. However, the easy way is to buy his readymade servo controller board that cost hundred plus for beginner version and three hundred plus for higher version.

One disadvantage of using this servo is that it doesn't have a feedback signal telling the location of the specified movement. The new and updated version of servo which cost RM350 each is capbale of doing so and can be link by network of 4 lines only.

Manufacturer Specs
This is the Futaba S3003 Standard Servo. This basic servo is used in cars, boats, or where standard servos are used. This is the replacement for the following servos, S138,S148,S22,S38 and S12.

This servo can produce high-current draw from your batteries. If using NiMH or LiPo batteries, make sure they are capable of delivering sufficient amps.

INCLUDES: One S3003 standard servo with preinstalled round servo horn FUTM00311 Four brass eyelets Four black rectangular rubber grommets (FUTM2348) Four servo mount screws One servo wheel 1-3/8" (35mm) in diameter One X shape servo arm 1.5" (38mm) across One star shaped arm 1-1/4" (32mm) across

SPECS: Speed: 0.23sec/60 deg @ 4.8V or 0.16 sec/60 deg @ 6V. Torque: 44 oz-in @ 4.8V or 56.8 oz-in @ 6V (3.2 kg-cm @ 4.8V or 4.1 kg-cm @ 6V) Size: 1.6"L x .8"W x 1.4"H (41x20x36mm) w/o output shaft Weight: 1.3 oz (37.2g) Connector: "J" type with approx. 5" lead

The USB Tester Board Part 2

The assembly for the USB Tester Board begins today. I managed to aligned all of the components except the 100k ohm where I discovered that I only have 5 pieces instead of 20 pcs. This means that I have to go to SS2 again to buy the part sometime this week. After rearrange the components, unfortunately not according to the layout as proposed earlier since I found out that its better to change due to space constraint on the actual PCB. The wiring would be completed once I get the 100k ohm resistors. This is how the new layout looks like.

As for the USB black box, today I also managed to connect all ports A, B, C from 3 X 10pins to 40IDC. So what left is to check with the written software that I did couple weeks ago. This is how it looks like once all the connectors inside are plugged in. As you can see I only do for one of the USB board since I planned to use the other for 8255 upgrade. As the IBM Thinkpad is with Mr Khow for him to study C programming, I will continue with the hardware fabrication.

Give short briefing regarding the Borland Turbo C programming method to Mr Khow. Show him how the program works as well as setting up the PC and Thinkpad for programming training. Mr Yu also brief him the basic of PC interfacing using the 8255 PPI board.

Meanwhile Mr Yu TT request to go ahead with the Robot project while waiting for Mr Khow to learn C. So he asked to get the quotation for required items such as servo motor from Vanguard as well as aluminum from Sg Besi. If possible he wants it to be available by Wednesday so that the work can be carried out to built the robot after holiday, end of this month. The priority now is to built the robot, then followed by Mooncake slider with pneumatic pusher. As for the pusher, the control would be hardwire rather than exclusive electronic control.

The drawing of USB Port Tester Board

Today I sketch an official drawing for the USB Port Tester Board. This circuit basically tie the input to input high (1) when there is not input present. Connecting a switch to GND would trigger the INPUT port to low (0). In short, so (1) is OFF and (0) is ON then. As indicator, when the input is on then the LED will light on. This is the circuit diagram for the design.

Once the circuit diagram is completed, then I design the parts/components layout to facilitate the PCB fabrication later on. This is the TOP view (component side) of the PCB. Here is the board layout design. As for the parts required to built the circuit, they are just some common parts only. To make board nicer actually its better to use the array type resistors. But then since it is not available in SS2 that day so I just use the discrete type which occupy more space and more wiring. However, the result would be the same then. The 1kohm is R1, 100kohm is R2 and the R3 is 100 ohm. As for LED I will use two different colors, GREEN and YELLOW to differentiate the ports. The usage of IC socket just simply to make the IC replacement easy in case of IC faulty.

To get the full version of the design click here

The USB Tester Board Part 1

Today I managed to complete the 40P IDC Female connector interfacing from USB board ports A,B,and C to the black box USB casing. However in this diagram the 40P IDC is shown into two categories, port A and port B. In actual it is a 40P IDC female connector attached to the black box where 40P IDC pin number 1 is on the top left (GND pin) beside PB7. Another typeoerror is the PAO OV in which the correct one is PB0 OV. This view is from TOP (component side) for USB I/O 24MK3 and BOTTOM (wiring side) for 40P IDC. Click here to get this diagram.

I also install a 5V LED indicator for the LED board. The LED will light on once any hot USB cable from hot PC is connected to the black box. This is how the black box looks like from outside. However, for the ports A, B, and C 10pins connector are not ready yet since now it is about time to go back. I will do it tomorrow.

8255 desktop PC that having problem with the display yesterday, now come back to normal after servicing the motherboard. One thing to note, if this PC spoilt again, we might be in trouble. This is simply because the other spare PCs do not have ISA bus type slot that is required fort the PPI 8255 to work with. This is how the 8255 looks like.

The Beginning of Tester Board Assembly

Went to SS2 PJ to buy 2.2k ohm resistors and casing LED to complete the tester board assmebly.
Mr Yu TT assemble the DC motor trial PCB driller for Mr Khow. Next Mr Khow project is to design the mechanical holder for that driller.

8255 Terminal Board
This is how this board looks like. Mr Khow completed the 8255 terminal board connector tracing. Now it's my job to double check that it is correct. I'm lucky since the notes that I prepared 3 years ago that being kept by Mr Yu comprise this board connection. It saves my precious time indeed. Here is the board layout diagram. To download this layout diagram, click here.














8255 Tester I/O Board
Give the design schematic diagram to Mr Khow to assemble. Assemble one input circuit components for reference and let him complete the other 4 as well as DC 5V and 12V input to the tester board. He managed to complete it by end of the day and now I have to double check it to ensure everything is allright. This is how it looks like.

USB User Port Tester Board
Drill a hole for 40P IDC Female connector at USB black box. It will takes some time to finish due to job priority now is for 8255 refurbishment as well as upgrading Mr How knowledge about PC interfacing.

Get the photocopy of the old 8255 journal from Mr Yu files. Make 2 copies for myself and Mr Khow. The objective is to help Mr Khow understand the C programming and Assembly Language faster. Another problem that I face today is suddenly the old P3 8255 desktop PC no display come out.

The silly mistakes are happening ...

Resistor
The Shopkeeper gave 22kohm instead of 2.2kohm, and I also did not check that day. So today when I gather components for 8255 TBU, I just discovered it. So next Wednesday I guess I have to go to SS2 again. Yet another, the 100ohm and 100kohm I supposed to buy the array type to reduce wiring, but then he gave the discrete type. What a waste of time.

8255 Tester Board Upgrade (TBU)
The schematic drawing as well as components layout diagram have been completed. However since, the 2.2kohm resistor is not available yet, so Mr Khow cannot complete the fabrication of the board by Wednesday. The rest of other components are already gathered and keep in the store.

USB Port Tester Board Fabrication
The layout and and schematic diagram to fabricate the board already completed. However, the usage of array resistor and 2.2k ohm are required for better design. Need to go to SS2 again to get the parts.

8255 Automatic Egg Rolls Machine Test
The I/O cards are OK as well as the software and hardware. However, one stupid thing is not there. Some idiot had cut the pneumatic tube that used to supply the compressed air from air compressor to the machine. Since the replacement tube is not available for the time being, so the full test cannot be carried out. What a waste of time and effort for today, and what a stupid idiot dare to do such thing to the machine.

The Start of the 2nd Stage USB Project

Since the AC to DC 15V power supply with DC motor testing (as shown in the picture below) and the Visual Basic Coding are successfully completed, now it is the time move on to the next stage.


USB 24 I/O MK3 Input Tester Board
The design was completed and hardwares components were bought from SS2 PJ and ready to be assembled anytime. Some modifications to original design are required due to project target to replace the old 8255 PIT board. Since the connectors pins assignment are different, so two types of IDC 40P female adapter needs to be assembled. Yet another, the USB board do not have 12VDC supply. This means that I have to add an external 12VDC from other sources such as an AC to DC 12V power supply.

8255 PIT I/O Test Board
This part is actually a twofold mission. First, it's purpose is to help Mr Khow to familiarize with the PC interfacing world. Next it is to upgrade the old test board that I did for 8255 that comprise 5 output with a few connectors missing. Now it will be upgraded to 5 input and 5 output with full featured connectors.
Before he will proceed to the circuit assembly, first I have to redrawn the design for the upgrade. Next he himself have to troubleshoot the IDC 40PF board connectors to 32pin screw type interface board. The reason is just simply I lost my circuit design. Since it's quite simple, so the best way for him to learn to do it hands on.

Here is the list of today's purchase.

The Ports of the USB 24IO mk3

The Port Layout
Here is the ports layout of the board.


The Port Pins Configuration
Here is the port pins configuration.


The Port Pins Description
Each I/O pin can be configured individually as an input or output. An input pin is TTL level compatibble and an output pin can sink or source up to 30mA. Here is the description of the port pins configuration.


The USB I/O 24 module is designed to enable digital input/output signals to be interfaced to the USB port of a PC. The interface cards that can be used with ISA and PCI slots of PCs are based upon the Intel 8255A PPI and it is possible to configure the USB I/O 24 module to mimic this device.

The beginning of the hardwares assembly...

USB Board Housing
A black harden plastic box sizing 160x95x50mm is used to housed 2 USB 24 I/O mk3 boards. Now those two USB's are placed inside the box already which make it easier to use and safer to play with.

Tester Board
The components to built are being grouped so that later on they can be hatced or soldered into PCB. This board is very important in future usage as USB board confirmation OK incase some technical problem arised.

AC to DC Power Supply
Mr Khow is started to gather all necessary components to built the DC supply board. It is merely a 15VDC output circuit gained from an AC240V step down to 15VAC. The AC then is converted into DC using 4 pins bridge rectifier in which tied to 2200uF 35V electrolytic capacitor. Next the DC passes through an IC 7815 DC regulator with 2A current limiting to smoothen it that coupled with 2 ceramic 100nF capacitor. Here is the built circuit diagram.
Once the circuit is fully assembled, then it will be tested against 15VDC Motor.