[SOLVED] Project to replace CY7C64613 in the ICD2

szlovak
I know why buffers are used, but my question why some schematics use two identical buffers in parallel in the same direction?

hi Andy_123
that is for increase buffers power!

emcs51 said:

hi Andy_123
that is for increase buffers power!

Click to expand...

this makes no sence, why you need more power on the input side?

The buffers are already in the chip. Why don't use it?

Potyo: my to want to make a clone identical to the original, if this is possible.
only trate to help. i answer your question tomorrow, after of my work.
Best regards
Facaf
P.D. sorry, but my english is to bad.
[/quote]

Hi, I have some questions, I have a 25Mhz, 40 Mhz, 20Mhz oscillators. The 25 + 40 Mhz oscillators are powered, and the 20 is a regular crystal. I have problems with simple things like blinking an LED, And was wondering:

1)Can I use the powered oscillaotrs for the ICD2 programmer?
2)Do the powered oscillators need capacitors?
3)what is the nessecary capacitor value for the 20Mhz crystal?

By the way, for people who are looking for parts (At least in the USA), TI, MAXIM, Fairchild (Makes the 74HC, etc. type parts, Regulators DC-DC converters I beleive), Microchip, National Semi, Allegro, Atmel, Cypress, and Freescale, all offer free samples, as long as you have an account(signup is also free). Some of them like TI and Freescale even have free overnight shipping. They give them out in numbers that a simple hobbiest could use to make about one board. always go to the manufactuer's website, as you might be able to score some freebies .

About a post I saw earlier:

evc said:

First let me tell you what terrific work you've done so far! Congratulations!
And my question (it's more like suggestion) is - Why we don't try to put it all in one microcontroller - PIC18F4550? My idea is to load the operating system (originaly dedicated to be written into 16F877(A) ) into PIC18F4550's RAM (it will be enough, i think). And then the software of the 18F4550 to act like interpretator for this operating system. The only fault will be that you have to download this operating system every time when you switch on the power supply of ICD2, but the download will be much more faster. I think i can do it, only if i knew the comunication protocol between PC and ICD2. Any way, i will try to do it, with your support or without, but i like team play and think it will be fun. Unfortunately i have lately much more work then i would like to, so i don't know when it will be possible to visit this forum again, but still hope to receive some sign from you!

Click to expand...

I like the idea of one PIC, instead of two, and I own a PICKIT2. Me being a person who like to take things apart, the first thing I did was to of course take apart the PICKIT2. It uses a 18F2550, and has two 24LC512's, which I believe are for temporary program storage space (correct me if I am wrong). Would it work to have MPLAB upload code to the ICD2, which would load it into the memory, and then program the target, then switch over to the debugger?

Thanks for your help in advance,

Benjamin B. Roy

I like the idea of one PIC, instead of two, and I own a PICKIT2. Me being a person who like to take things apart, the first thing I did was to of course take apart the PICKIT2. It uses a 18F2550, and has two 24LC512's, which I believe are for temporary program storage space (correct me if I am wrong). Would it work to have MPLAB upload code to the ICD2, which would load it into the memory, and then program the target, then switch over to the debugger?

Thanks for your help in advance,

Benjamin B. Roy

Click to expand...

1. The two 24LC512's ane not used at this time.
2. MPLAB can use the PICLIT2 as ICD (only one device at this time - more to come)
3. I missed the 666 post on this topic

Hi Andy_123
going slightly OFF-TOPIC

With reference to the The Buffer Question:
One way to tell if your design is being copied (stolen) and therefore provide evidence in any subsequence law suit against a thief is to incorporate an inert, cost free and pointless design feature which nobody would create in their own design.
It could of course be poor design, a dormant feature or just insignificant.

You will find that most engineering is governed by commerce and not good engineering practice - if the two coincide then you are fortunate.

It is good that you ask the question but will you recognise the answer when you see it?

best regards ... Polymath

soo, what about my oscillator question? 666, do you know if the two 24LC512's will ever be used, or when they will? In fact, when is the next update for the PICKIT2 supposed to be released? Thanks,

Benjamin B. Roy

wonbinbk said:

Chamera said:

If I'm looking at the right schematic (they are all pretty much the same thing) L1 on the USB port is to filter the power for the board. See "Choke"

L2 is used for the DC step-up converter to supply higher voltages for MCLR on some IC's

If you really want to make the inductors, you need a multimeter or similar device capable of measuring the inductance as you wind it. Try to use a core, I've found the air-wound inductors I've used in PLL systems are near telepathic. Think a bad thought and it stops working!

If the inductors are a problem, you can always use a external power supply for the reference voltage until samples arrive.

Click to expand...

To Chamera:
Thank you very much, I have found the inductor. So, my problem is solved. Thank you!

Here is my PCB, schematic redraw, all in pdf. I hope I can give a hand to this thread. And hope it is useful for all of you.
The Header-4 pin is the USB connector, just solder 4 wire of USB cable on it. The Header 6 pin is ICSP header which its first pin is MCLR.
The Firmware is downloaded in PiCs post.

Click to expand...

Do not etch your board if you use my PCB. Because I have found an error on it. I will post the right one soon. Sorry for the mistake.

Hi, this guy uses a PIC18F2550, but it is not MPLAB compatible I think.

https://www.microengineeringlabs.com/products/usbprog.htm

Benjamin B. Roy
https://initialdrivegtr.po.gs/

I just finished etching one of PiCS's boards, and this is only my first time making a PCB, and I think it looks good. I attached a picture of it before I drilled the holes.

Potyo! Üdv!
What is value of the R2 and the C1 on your last schematic? (mert ez lemaradt!)
Did you test your circuit?

Today i have assembled the 12F683 based voltage generator using modified code by Mike, K8LH(thanks for it).

If i select an 5V device(16F870, 12F683, 10F200 or 18F252) then MPLAB ICD 2 Vpp is 15.7V and Target Vpp is 13.6V. The self test doesn't pass, because the Module Vpp is high. Programming of 16F870 works fine.

If i select an 3.3V device(PIC24FJ128GA006 or dsPIC33FJ128GP706) then icd2 sets the MPLAB ICD 2 Vpp voltage to 6.87V (multimeter shows the same result), and Target Vpp to 4.95V(measured by 16F877A). The self test passes.

Currently i don't understand the reason of the difference between two Vpp's. Maybe my inductor saturates, after switching on the LED on the Vpp. Tomorrow i will replace the inductor, and see, what happens then.

MPi said:

What is value of the R2 and the C1 on your last schematic? (mert ez lemaradt!)

Click to expand...

C1 is to filter the target Vdd voltage, you can use 100nF. For testing i have used 470Ω as R2, and 3.3mH as L1 with Isat=240mA.

Potyo, maybe check resistor values on RA0 and RA3?

Today i have improved the code of the 12F683. The PWM frequency is now 80kHz, and the duty cycle is no more adjusted step by step, now it is increased or decreased by the difference between the required and the measured voltage.
Now the Vpp voltages are between 12 and 12.5V for an 5V device. For the 3.3V devices Vpp is not used, so there is no need to monitor it.
Here is the code.

Yes, It's my PCB version 2.

Here is my USB ICD2 PCB! Now, with small dimension in one layer, it has only 8 jumpers.
I have tested it. It works like a BMW car! Hehe! All the value of Components is OK.
Note: I use schmatics PICs had posted. With no VPP regulator

Re: Yes, It's my PCB version 2.

wonbinbk said:

Here is my USB ICD2 PCB! Now, with small dimension in one layer, it has only 8 jumpers.
I have tested it. It works like a BMW car! Hehe! All the value of Components is OK.
Note: I use schmatics PICs had posted. With no VPP regulator

Click to expand...

Sorry to here that your ICD2 is as slow as a BMW!
I cannot think what the problem can be! Xtal or Diesel?
My ICD2(Cpress) leaves a BMW for dead ......
Perhaps a change in fast vehicle perception would help!!

Nice job - Well done wonbinbk
best regards ... Polymath

Just a thought, but does anyone think that support for AVR or other devices could be added? Not through MPLab, but in general?

Benjamin B. Roy

Re: Yes, It's my PCB version 2.

wonbinbk said:

Here is my USB ICD2 PCB! Now, with small dimension in one layer, it has only 8 jumpers.
I have tested it. It works like a BMW car! Hehe! All the value of Components is OK.
Note: I use schmatics PICs had posted. With no VPP regulator

Click to expand...

I searched for 100uH inductors on the Mouser site and came to understand that I did not have enough info to choose one.

Could you provide a manuf and part number for the inductors.

Are the resistors all 1/8 watt or can I get by with 1/4's.

3v0

You don't need more info in the inductor, except the saturation current(Isat), which must be higher than 200mA.
You can use 1/8 or 1/4W resistors, this is not essential.