I want to build a pic development board.

[jdraughn]

pic development board

I have been using a PIC18F4550 to teach myself how to program microcontrollers and how to build circuits. I just have it in a breadboard and wired a ICSP header, a little LM1705 power supply and a crystal with the requisite caps. Problem is that those components makes it a little hard when i want to actually wire up some real components. The crystal sticks up way high and my home made ICSP header is kind of loose.

I have everything I need to make a PCB but the design.

I don't want to spend days and weeks learning how to use eagle, I keep trying to modify the very simple hackaday pic18f4550 design to add some headers for the ports, get rid of the boot loader circuit and add my ICSP header, but it's taking me forever and I keep getting stuck. Last time I went through and made a ton of changes but when I went into board view, I couldin't move my headers around.

I do want to learn eagle, just not at the moment. I actually have at least two lengthly tutorials on how to use it, I just don't have time to go through them right now.

I also just placed an order for a couple of zigbee modules (MRF24J40MA), a couple of ethernet addon chips (ENC28J60) and some smaller, but still USB enabled microcontrollers (PIC18LF13K50). I am looking forward to concentrating on building some circuits and learning how to code for them. So far I have just done some simple PWM to dim LEDS and move servos, but thats about it.

Does anyone have some basic prototype boards for some pic chips they would be willing to let me use? I don't really have any need for buttons and leds on the board, just headers would be fine, as long as the ICSD header, power connector, crystal and maybe even the USB port is built into the circuit board.

I would prefer to keep the costs down by just having headers on the board.

I am planning on making a wireless thermostat I could program from my computer using multiple temp sensors throughout the house, wireless sprinkler timer, and I have toyed with the idea of making a remote controlled lawnmower with a little automation built in. Lots of other ideas too, but that gives you an idea of what I want to do.

Thanks.

By the way. I searched and found a couple of where people were making their own boards but it looked like the projects either fizzled out, or they just stopped posting progress.

 

[wp100]

pic development kit

Hi,

Sounds like you are gathering a great deal of hardware before you have started on the coding.

My initial thoughts are that you are in need of a ready made development board like the Mikroe EasyPic range which has loads of add on modules etc.

If you still want the diy route - perhaps you should build your core circuits like the psu, display, leds, switches and pic socket onto a large strip board or similar so that you have good solid soldered joints - breadboards are fine for one off tests but your core stuff needs soldering imo.

If you want a pcb - then perhaps a more modular approach would be better for you, again regular things like psu, display, switches on a 'motherboard' with connectors allowing you to plug in different 'project' boards - a pic of my board shows the idea.

Sure others will come in with other ideas to get you going.

 

[eltonjohn]

pic development board schematic

This days electronic designs are done mostly in a VIRTUAL way .Before you spend a dime in a screw .Most of digital and analog design as well as microprocessor development can be done in a simulator like Proteus or Coware .The advantages are enormous you can change any thing, any time without wasting money .Only when your basic design is validated you can start building the plataform in a most optimized way ....Most of those enviroments allow to interact with ports and Usb as well as other simulation enviroments like MATLAB etc. So you can even simulate physical machines integrated with electronics .This is how is done this days .!

 

[jdraughn]

pic development boards

Thanks for the advise guys. The more modular approach is more to my liking, thats why I want a basic protoboard with just some headers, that way I can just plug my board into a different board which has the actual input and output.

As far as designing the circuits goes, im not ready for that quite yet. I am a very visually oriented learner and seeing circuits I make actually work psychologically helps me learn more so then seeing it simulated.

I have been accruing much hardware and components because every single freakin time I go to build some little circuit, I am missing something, radio shack won't have it and there is a local place that sells IC's and a variety of components, but they are a huge rip off, so I spent the money instead online so I can start to accrue a pretty good inventory.

One thing that I do plan on building pretty quickly is a differential controller for solar hot water heater, but I would like to be able to log and view day to day history which is where the cat5 or wireless comes would come into play.

What kind of board are you using wp100? That seems more suited to what I want.

I am going to start going through the eagle tutorials I suppose.

 

[wp100]

how to make pic development board

Hi,

What kind of board are you using wp100? That seems more suited to what I want.

Just my own one off design thats developed over time, the original was just built on strip / vero board.
I copied the ' E-Bock' idea of using D25 type connectors to allow me to plug in a different cpu type / project without affecting the main board stuff.

 

[jdraughn]

mrf24j40ma pin soldering

Ok, I bit the bullet and have spent the last few days trying to make board after board in eagle, and I think I have a workable prototype.

Can you guys take a look at this schematic and board layout and tell me if you see anything wrong with it?

I plan on making sure my power supply is clean, hense no filtering caps (but I may add just one anyway), but basically it's just a very basic breakout board for my PIC18F4550 so I can just plug in the ports I want to use into my breadboard.

There were so many variations of resistors and capacitors all over the net, I hope I have the reset circuit and ICD connection circuit right.

I am thinking I will also make bigger traces wherever I can before I try etch my board.

I tried to keep it all one layer but I ended up having to use one jumper wire near the top.

Thanks much, if this works out ok, I will take it up a notch and add power supply and USB, and maybe some basic built on i/o.

 

[wizpic]

pic development board pcb

Looking at the schematic and PCB , You will need to add a 4k7 or 10K resistor on to the MCLR pin then feed it with 5V, The way it is at the moment is you will short out the the 5V supply. Aslo you need to add a diode in line otherwise when you program the pic you may casue 13V to go into 5V so set it up like this below

If you have a look on this there are schematics for development boards which may give you some ideas
https://www.melabs.com/doclist.htm#X1

 

[wp100]

pic development board usb

Hi,

Agree with Wizpics comments plus a couple of other points,

First - your are going to do a difficult double sided board so you have some parts on both sides ? - seem a bit o.t.t for a little board like that ?

You haven't mentioned what type of programmer you are using - can you integrate it onto the board ?

You say your power supply is clean, hence no filter caps, you must fit some, as per the manufactures data sheet on the input and output rails of the regulator and 100nf across both pin 11/12 and another across pin 31/32

You are using the 4550 USB chip, but have made no provision for the USB parts, apart from the usb socket there are extra caps /res needed for usb that like those 100nf caps must be fitted as close to the 4550 pins as possible.

Equally if you do not want to use USB for a while, you can run the chip off its internal oscillator rather than fitting a xtal.

Think when you actually get working with your completed board, you will appreciate having plenty of free space around the main ic to solder extra bits on to - just put leave a boarder of 25mm / 1" around the IC and fill that space up with ic pads and similar so you have some anchor points.

While there is merit in having a completed project board as small as possible, keeeping things so tight on your development kit will actually be a pain, imho.

 

[jdraughn]

building your own developer board

Thanks for the help guys. I will add the resistor and diode.

I am building this board strictly as a breadboard kit. But now instead of taking up 20 pins worth of my breadboard by plugging my chip directly into it, I will only use what I need. If I am only using 4 ports, then I will only use 4 pins worth of breadboard, leaving lots of open space.

if I want to add USB later, I will either make a seperate little breakout board with the usb connector and needed components which will have a 4 port pin header.

Later on I will make a pretty nice developement board, but it seems to pointless to spend money on a premade one when I can get some good learning experience making my own, even if it cost a little more in the long run.

I have actually been using a 12v adapter with a 5v voltage regulator on my breadboard, which I will continue to do, but the next circuit I design will be a simple power supply.

Oh yeah, I almost forgot that I am planning on making a portable power supply that has a 1.5 watt solar panel on top. It will generally keep the AA or AAA batterys charged, since when I actually draw power as I am experimenting, it's usually in small bursts. I would also have an AC plug so I can power/charge directly if needed.

I take most of my stuff with me to work everynight, I have free time and thats where I do a lot of my experimenting, soldering and all.

Edit: forgot to mention, I have a ICD 2 LE programmer/debugger, it uses only 5 pins, it doesn't use the 6th.