I need someone to confirm to me that this will work as intended
I need to know if the crystal, leds, resistors and headers are in the correct place based on the 328P-AU Atmel Micro-controller.
Any assistence would be great
The pcb will be programmed to blink 5 leds in series via the PWM pins of the chip.
I need to know if this is usb and ftdi breakout-able.
Again this is my first ever smd type pb so please let me know if any problems you see.
Why a atmega328?
I use a at-tiny85 for this sort of thing. But with that said.
You assume the ground pins are connected internally, Is that the case?
Why a 16Mhz crystal? To blink LEDs you can use the internal 8Mhz RC oscillator and save money and power.
Good luck
R.G.
ps Who are you using to make your PCBs?
pcb
Please post schematic if you are looking for help on pin usage.
Power and Ground traces look
Power and Ground traces look too narrow
Are you sure?
Why not use back side for PWR & GND?
It’s a single sided board i’m fabricating my self with the required etching materials.
Why a 16Mhz crystal?
I need the crystal to program the chip, the board is just for testing random led patterns and eventually it may be repurposed so it needs to remain programable.
My question is:
Does the circuit look correct?
trace width
There are online calculators for trace width depending on length and current. It does not cost you anything to make a wider trace. You should also connect all the CPU GND pins together and all the Vcc pins together.
I modified the width of he
I modified the width of he traces to 18, Also all the vcc and gnd’ are connected, are you saying there is nothing else wrong with the schematic if those are the only issues you see?
PCB
Did you post the schematic and revised artwork? Are you aware of the batch PCB services such as OSHPark, DirtyPCB, and SeeedStudio to name a few?
Yeah i’m aware of pcb
Yeah I’m aware of pcb fabricators but I would prefer to learn from this experience so I can create my own circuit boards ON-THE-GO.
Any more assistace with the ACTUAL circuit diagram would be appreciated.
Schematic
If you can’t post schematic I can’t possibly say if it will work. I have reverse engineered PCB designs before but have no desire to do yours when you can supply the original.
I never built a schematic
I never built a schematic for this, I can provide you the chip diagram?
All i want to do is program the chip (on board) to flash the lights however needed…
the circuit i put down is what i could gather based on what i have looked around for online, The circuit should be simple ftdi i/o headers which i can connect to a (chipless uno) rx/tx/reset/gnd/3.3vcc, i don’t see how i need to draw a schematic when the diagram above should be easy for anyone to figure out within a few seconds.
Before i jump to making this circuit i thought i would ask some likeminded people to conclude that the wiring should act as required?
Based on this chip pinout, it should be simple enough for someone to look at the pins.
Example of components without ftdi header(s)
The 101 resistor should be 103, so ignore that.
you need a schematic…
In order for us to understand the circuit, you need to provide a schematic diagram. Without it we can only make general comments.
The 22K resistors seem very high for current limiting the LEDs.
There are more then one boot loader.
The Arduino Pro boot loader has a 8Mhz version for the 328.
But its dealers choice and I only offered the idea as a way to trim a few pennies off the cost.
R.G.
PCB
I have been doing this type of work for some time and always start with a schematic. I tend to think of schematics as “What I want to do” and artwork as “What I did do”. Makes it much easier to ask for review.
My preferred tools are the GNU gEDA tool set with gschema and PCB. They, like almost all others, allow a smooth transition between the two views with error checking. gEDA plays best on Linux and very poorly on Windows. Two other popular options are KiCad and Eagle. What do you use?
If this is your latest artwork please notice the thin traces between the pins on the FTDI header.
Thanks, I’ll check it out
Thanks, I’ll check it out and get back when i can, Time to learn another peice of software (facepalm)
I’m not sure if this is how
I'm not sure if this is how schamatics are done however I have modified the circuit a little.
Also, KiCad has no momentary push button in the libs o.0???
Notes:
# Only one led is in this circuit, no need for the others.
# Changed FTDI for ISP Header (FOR PROGRAMMING, NOT BOOTLOADING) doh!
schematic
Good start. Lookup how to create named signal lines. It can help reduct the crossed lines and convey more intent.
There, i hope that helps
There, i hope that helps Please advise if the circuit should act as a programable led
Just so you know, this is just a test, i don’t care about the cost.
Diode on reset line
You wont need D? on the reset line. Most circuits just have the 10K pullup to Vcc and the momentry push button to ground. C1 should be a 100uf electrolythic (mind the polarity !) for a bit of extra power supply filtering. Minor suggestions…
PCB
Noted, Is this the only
Noted, Is this the only issue you can see with the actual wiring though?
