2007 20 Nov

This test will be part of one of the main module that I will need to communicate between PC and all sensors/modules. I want for the PC from the robot to communicate with one Master PIC by RS232, exchanging commands and information to/from sensors/modules. Than the Master PIC will make the interface to all sensor/modules by I2C Bus.

Still have a lot of work to do on the H-Bridge module, and the I2C Bus, but decided to test RS232! It was fun to play with and my test worked well!

I’ve just assembled on a test board this simple circuit:

Pic16F628A RS232 Test

Continue reading »

2007 19 Nov

Now that my lab tools are all set I need to test my Pic16F628A to get a PWM signal. This signal will later be applied to the H-Bridge circuit that will control DC motors power. For the test I’ve used this circuit:

Pic16F628A PWM Test Continue reading »

2007 17 Nov

Just made some tests to see how CCSInfo Compiler works! I’m really impressed! Very simple and easy!

For this test I’ve used Microchip PIC 16F628A working with an external 4MHz resonator and 1 led connected to the RB0 (pin6) - also requires one 1KOhm pull-up resistor to the led and the MCLR resistor to VCC.

Led Blink Test

  1. #include <16F628A.h>
  2. #use delay(clock=4000000)
  4. //————————————————————————————————————————————————————————————
  5. void main(void)
  6. {
  7.   delay_ms(100); // power up delay
  9.   setup_comparator(NC_NC_NC_NC);
  10.   setup_vref(FALSE);
  11.   set_tris_b(0b11111110);
  13.   while( TRUE )
  14.   {
  15.     output_low(PIN_B0);
  16.     delay_ms(500);
  17.     output_high(PIN_B0);
  18.     delay_ms(500);
  19.   }
  20. }
  21. //————————————————————————————————————————————————————————————

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2007 16 Nov

I’ve previously work with Microchip Pic using MPLab and Assembler language! It’s very powerful but also time consuming! Now I’m using one tool to develop my Pic code from C language. I’m very impressed, It’s very easy to develop and there is a big community in the web that creates C libraries for tools like this!

This is a list of the software that I’m using now to develop on Microchip Pics:

Microchip MPLab8 IDE: (MPLAB)

Nice tool to code Assembler for pics but I’m using it to debug C code from CCSInfo PICC. There is one plug-in to integrate both tools! Excellent!

MPlab8 Continue reading »

2007 01 Nov

I’ve just completed the 2nd H-Bridge circuit to command the DC motor. Since my time is short I decided to make the circuit on a test PCB board. I’m also a little rusty on the PCB software (Protel or Eagle - no more Orcad for me, I’ve had my share!). I’ve done better circuits, but this works and I’m good with that!

botdream interface Continue reading »

2007 30 Oct

It’s been quite a while !!! I have finally dropped all my extra-projects to take good care of my botdream.com.

Still need to finish the 2nd H-Bridge circuit to power up the DC motors. Next I will need to create the hardware interface between PC and modules (H-Bridge 1 and 2, temperature, distance sensor, etc). For that I will use a Microchip PIC 16F628A that will connect to the PC Serial port to communicate with applications and by the other side to an I2C BUS that is connected to the modules!

2007 31 Jan

I’m currently moving from town and need to settle down before I can restart this project … sorry about this! I have also a lot of work to develop and no time left for my hobby. I’ll be back as soon as possible!

2007 07 Jan

Now that the robot’s PC is operational I’ve decided to start with the H-Bridge hardware to drive DC motors that is controlled by PWM (Pulse Width Modulation) signal. Still need to make the interface between H-Bridge and PC, but at least I can check first if everything is going has it should. And I’m glad i did!

It seems that the extra battery that I’ve installed to drive the motors (6VDC 4.5Ah) is not working properly with the H-Bridge that I’ve implemented from H-Bridge Circuit.

botdream interface
(I’ve used this circuit because is simple to implement, cheap and controlled by Pulse Width Modulation signal, quite easy to control when using Microchip PIC)

This bridge uses Darlingtons transistors and will have some losses between 2 to 4VDC at maximum current. Since DC motors need 6VDC and my battery is 6VDC less 4VDCmax from circuit losses, I can’t use this circuit to drive the motors. I need to use MOSFET based H-Bridge … Continue reading »

2006 14 Dec

As previously mentioned (Project Description), I’ve decided to install Microsoft Windows 2000 to control the CPU because It’s easy for me to develop custom software on this platform. Also from ‘robot vision’ perspective it’s more simple to grab web-cam video stream directly to be analysed for that same custom application, since I’m a Borland Builder C++ developer and at this moment I have all the necessary tools to do the job!

Really like Linux environment, but at this moment I’m not familiar with the system ‘development wise’. Sure that my next botdream version will consider Linux has my first choice!

Necessary steps to install O.S.

I’ve attached one temporary CDROM into the 2nd IDE channel only to install windows 2000. Removed it after windows installation was completed. Installed the wireless network communication module on one PCI slot (forgot to copy the drivers! copied them into a USB pen drive). After successful configuration of the wireless card, managed to access the Internet. Installed all the Internet updates. Installed and configured SSH for console remote access. Installed UltraVNC for remote access. Configured PC BIOS and removed ‘keyboard not found’ error from boot test. PC is now ready to boot with no external dependency. Finally installed the web-cam.

2006 07 Dec

PSU, CPU, Wireless card, web-cam USB and fan cooling system is now in place. Also mounted a fuse to the main power supply line 12VDC.

botdream assembly Continue reading »