New project on HHH - 0 - 60MHz 5-digit frequency counter using PIC16F628A

Post new topic   Reply to topic

Go down

Re: New project on HHH - 0 - 60MHz 5-digit frequency counter using PIC16F628A

Post by Admin on Wed Jun 20, 2018 8:26 pm

Hi John,
Just spent 30 minutes composing a reply, then the browser crashed!

I love that counter circuit, and I learnt a lot from it. It began giving a 1MHz error after a course I presented. One of the students had re-programmed it. Wolfgang gave the source assembly file, so I learned a lot by first disabling the programming, then removing the surplus code.

If you want something simple then take a look at the CD4743 (HEF4743V) chips. It is a complete 4-decade BCD counter with latched and a multiplexer. All you need is add a BCD-2-7-Seg decoder and a CD4060 oscillator /gate and display driver to build a 0-19999 Hz counter. CMOS prescaler to anything up to GHz region. Can be cascaded to get 0-199,999,999 count.

I learned PIC programming in very simple stages:

- lesson 1 - "hello world" switch ON an LED
- lesson 2 - "hello world" switch the LED OFF
- lesson 3 - "hello world" loop and timer to make it blink

So I programmed two outputs in anti-phase, dropped the time to give 50Hz and I had built an 12v to 230v AC inverter.

- lesson 4 - Define and read input pin

Added 50Hz / 60Hz. Added a pair of beefy power FETs and my power inverters were born. See www.sm0vpo.com > power section

The most interesting project was the "servo exerciser". Drive four servos continuously, each in a totally different position. Coded that on an aeroplane, and I got more than a little interest/attention from the stewardess when I plugged a home made PIC programmer into the PC.

As you say, copying HEX files is not exactly programming, but it is a good start for the novice to get that initial confidence in using PICs with a first working project. Then people who provide source-code are real heroes for people who want to go deeper into programming.

I also use (self programmed) PIC at work, powered by the RS-232 port; only PIC, diodes and capacitors, and I can send "standard" command words to a handover unit for setting up test scenarios. But ll my stuff is really basic and simple. I am no expert programmer.

Very best regards from Harry - SM0VPO

_________________
(no text given)
avatar
Admin
Admin

Posts : 565
Join date : 2012-11-24
Age : 66
Location : Märsta, Sweden

View user profile http://www.sm0vpo.com

Back to top Go down

Re: New project on HHH - 0 - 60MHz 5-digit frequency counter using PIC16F628A

Post by John_1981 on Sun Jun 17, 2018 8:22 pm

Harry, 

Good to see a new project on the website. The amount of hardware that can be saved using a microcontroller is astonishing. I have recently been working on a frequency counter but my programming skills are limited, so my approach was to use a series of 74HC393's to provide the counting, then 74HC165's to shift the count serially into a PIC. The PIC provided the timebase, arithmetic and binary to BCD conversion, with the display controlled by a MAX7219 display driver. Of course, most of this hardware could be replaced by software routines in the PIC itself. I then bought a second hand 600MHz frequency counter at the right price and ended up shelving the project, but the programming skills I learned will be useful for future projects.

The only issue I have with designs such as these are that there isn't much scope to learn programming skills by loading someone else's HEX file into a pic and soldering the connections. I do not mean this in any way as a criticism, the project is an excellent way to quickly homebrew a low cost, simple frequency counter, but I would encourage anyone who is interested in using microcontrollers to have a go at writing their own programs. Start by getting an LED to flash on and off.  I find it just as rewarding getting a piece of my own software to work as getting an electronic circuit to work. 

Perhaps a DDS VFO would be a useful project to follow the frequency counter. Although the AD9850 modules are not as cheap as they were a few years ago, I think they still represent excellent value for money. I have been working on a program to control the AD9850/AD9833 types using a rotary encoder, 4x4 keypad and a 7 segment LED display module, providing direct frequency entry or rotary encoder control with a variety of step sizes available. Although there are plenty of designs around using LCD displays, I find a 7 segment LED display much clearer and easier to read.

John_1981
Guest


Back to top Go down

New project on HHH - 0 - 60MHz 5-digit frequency counter using PIC16F628A

Post by Admin on Sun Jun 10, 2018 3:36 pm

Hello, a little update ont he homepages.
I have today uploaded the latest project, complete with PCB foil patterns.

http://213.114.131.21/pic/pic_counter_01.htm

the project is based on Wolfgang Buescher, DL4YHF frequency counter, but I took a few liberties and modified the software, and added two different display boards. One board is for large 14mm 7-segment displays so that I can present to 60+ students on my courses. These displays can be read from about 7 or 8 metres Very Happy 

The software i edited and took out the meny and frequency offset, so the PGM/OFFSET function o the original unit has been removed. This is because 60+ students always push every button, flick every switch and twiddle every knob in sight. It got kinda tiring having to re-program all the instruments for each demonstration.

The article is published with permission from Wolfgan, and if you want to look at the original article then you can find his info on

http://www.qsl.net/dl4yhf/freq_counter/freq_counter.html

In this project I decided to include the PCB foils in the project itself. Makes it wasier for you to download them Smile 

BR Harry - SM0VPO

_________________
(no text given)
avatar
Admin
Admin

Posts : 565
Join date : 2012-11-24
Age : 66
Location : Märsta, Sweden

View user profile http://www.sm0vpo.com

Back to top Go down

Re: New project on HHH - 0 - 60MHz 5-digit frequency counter using PIC16F628A

Post by Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

Post new topic   Reply to topic
 
Permissions in this forum:
You can reply to topics in this forum