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I have been studying PIC 18F67J50 and have order it to make some tests! Since this pic use a very small package TQFP 64 pin (0.5 mm pitch between pins) it is not possible to just connect some thin wires and connected to the breadboard, so I have ordered this demo board but made a small mistake, it is a 0.8 mm pitch, damn:

Ok, let’s order a proper demo board, this is the result of my first work with TQFP devices using a 0.3 mm tip on the iron (iron? yes, I did it the old way, after all it was my first time! Thanks to my friend dinix to let me use is lab!):

Not bad for a first time! Now I can actually run some live tests with it! This is also my first time with the super power-full nano watt pics from the 18F family!

I have now a new USB In-Circuit Debugger ICD2 that will allow me to program PICs much faster than my old LPT (parallel port) one and debug my PICs hardware by using proprietary Microchip protocol. I have made some test programing my old PIC 16F628A and new 16F690. It works fine! Really fast and have less errors while flashing the PIC. Also, this is now integrated with Microchip MPLAB, just need to activate tool, connect and flash! No more switching between different tools!

Will make real time hardware debug as soon as possible! I’m testing my new PIC 16F690 on I2C communications! Slave device supports I2C Hardware protocol. Master device will need to be implemented by software! Will post results as soon as possible.

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!

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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.

(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 »