Making a PCB board from a schematic

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Keith R

Active member
I would like to turn this schematic into a through hole 1x1 board.
My input is 9 volts and the output is a 3mm led to make a FRED or EOT for an O-Gauge car. The plan is to make 10 boards and solder them myself. Surface mount would be OK as long as my input and output were through hole. The whole thing (with 9 volt battery) needs to fit on a 1" x 3" footprint to fit inside the car. I am asking for help for the best solution that is both elegant and easy. Not looking to sell these, just put them at the end of my Christmas lighted trains that do not have cabooses. Below is the schematic. I have the values for the components.
 

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A quick and cheap option that you'd be able to start with early next week is this from Amazon. It's virtually the same, other than D!, D2 and RB sharing holes of RP1.
 
Ernie,
That is pretty cool. I'll have to take a closer look at that. My LED on time is .2 seconds and off is 1.3 seconds. The resistors would have to change to accommodate the slower times (5HZ is too fast). I have downloaded KiCad and am starting on the video tutorials. I have already built a prototype on a 1x1, but it is pretty ugly (solder bridging 0.1" spacing and the like).
 
I was one of the original DIY'ers and there's no shame in modifying something that already exits. For about three bucks, you get the major components. Just modify a few values and eliminate those that you don't need.

Before I retired, my parts bin was the trash can. The very first Renard 64 channel controller that I prototyped was made mostly from components that were being thrown out at work.
 
There is another possible approach, although I think that most here would poo-poo the idea. The PICAXE line is a series of microcontrollers that can be programmed in Basic (or a Basic-like) language on a PC and downloaded through a simple serial cable tp the device (no special programmer needed). Likely the biggest drawbacks are that the PICAXE parts is that they are 5V parts, which would require a 5V regulator to drop the 9V from your battery down to 5V, and the lack of instantaneous gratification.
 
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The advantage of this approach is that it is more flexible. The period and duty cycle of LED control signal is easily varied, the brightness can be controlled through software, more than one LED can be driver (although the firmware would be somewhat more complicated), and the actions can be triggered by an external signal (PIR, reed switch, etc).

Way back in the day (2013) I designed a project for driving a pixel string on a standalone basis. It involved a PICAXE-08M and an outside PIC12 part (running a variant of the PX1 firmware, although that is not used in this suggestion). The PCB was 1.15"x1.76", although the design was a bit of overkill.

If I was designing a project today to drive just a discrete LED, it would use either a USB-TTL serial module module or a 3.7V LI-PO battery for power, and would ultimate end up as about a 0.6"x1" board. I don't think that I would design it to run off anything higher than the voltage from 3 (or 4) AA/AAA batteries.
 
I used to use a PIC10F200 as a timer/flasher for LED's when that part first came out. It's a pretty small part, I was used to soldering a lot of miniature surface mount parts back then, though. Microchips marketing, at the time, envisioned that the part might obsolete the 555 timer.

The advantage of a microcontroller is that you would only have to trigger it and it could also flash and turn off after a pre-determind time.

The I/O pins can source or sink a maximum of 25 mA, so you may not need any other parts except on the the power input.
 
ErnieHorning said:
I used to use a PIC10F200 as a timer/flasher for LED's when that part first came out. It's a pretty small part, I was used to soldering a lot of miniature surface mount parts back then, though. Microchips marketing, at the time, envisioned that the part might obsolete the 555 timer.

The advantage of a microcontroller is that you would only have to trigger it and it could also flash and turn off after a pre-determind time.

The I/O pins can source or sink a maximum of 25 mA, so you may not need any other parts except on the the power input.
Click to expand...
As you may remember, I used that part as a dimming pixel controller in the times before the WS28xx parts appeared on the scene. It was controlled by a Vixen2 output driver that transmitted data at 38400 baud (if I remember correctly) with the serial input and pixel driver code interleaved in a somewhat gnarly fashion. In fact, I may have even sent you the code for that.

In any case, the PICAXE-08M is just a relabelled PIC12F1572 programmed from the 'factory' with a bootloader to download code compiled by the PICAXE software in a PC.


Edit - PIC12F1840. not PIC12F1572.
 
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Yes, I still have those micro's. They worked like a charm! I never used them, but I could have. :) They're all assembled, I think, hanging in the attic. Maybe I'll resurrect them some day. I think ESPixelstick and be configured to 38,400 baud and xLights would be just fine with it.

Yes, the PICAXE would be easier to program. There would still be the issue of the board in OP's first post though.
 
Keith R - are you ordering those modules from Amazon (or your vendor of choice)? You might need to add an external resistor in series with the LED, depending of which ones that you're using.
 
I first thought of using an ATTiny13, simple basic programming, and a small footprint. I have lost all of my basic files, though (used these for timing Halloween props on and off in the past), and have forgotten the method for programming (all of the fuses and crystal timing). A 555 astable timer seemed to be the simplest.
I tried programming the tiny13, but something was wrong and it would not compile. It's been so long since I did that.
Going from 9v to 5v with a 7805 is not an issue, and the LED will be turned on with a mechanical switch, not a PIR. The 9v battery was for longevity, considering the car would have to be taken apart every time the battery needs to be changed. I will probably implement a tray, to make it easier to remove and replace.
I will locate my program for the tiny 13 and post later today, but hopefully the end result will be a board I will either etch myself or send out to have made. Considering the small footprint and the quality of the manufactured boards for the price, I was leaning that direction
 
Keith R said:
I first thought of using an ATTiny13, simple basic programming, and a small footprint. I have lost all of my basic files, though (used these for timing Halloween props on and off in the past), and have forgotten the method for programming (all of the fuses and crystal timing). A 555 astable timer seemed to be the simplest.
I tried programming the tiny13, but something was wrong and it would not compile. It's been so long since I did that.
Going from 9v to 5v with a 7805 is not an issue, and the LED will be turned on with a mechanical switch, not a PIR. The 9v battery was for longevity, considering the car would have to be taken apart every time the battery needs to be changed. I will probably implement a tray, to make it easier to remove and replace.
I will locate my program for the tiny 13 and post later today, but hopefully the end result will be a board I will either etch myself or send out to have made. Considering the small footprint and the quality of the manufactured boards for the price, I was leaning that direction
Click to expand...
OK, I've been a bad boy by offering unsolicited (and somewhat off-topic) advice and potentially hijacking your thread. What I've done is designed a 0.8" x 1.025" pcb for mounting a PICAXE-08M2 (which, as I've noted above, is a pre-programmed PIC12F1840) with added features to suit myself. Apart from the PICAXE-08M2 and connectors, I've included a footprints for a dfplayer (to play mp3 files from a uSD card through a loudspeaker) and for an 8-pin i2c serial EEPROM (I have a few Microchip 24CS512 parts on hand). There isn't any regulator, so it operates off 5V instead of 9V, includes current-limit resistors in series with the outputs. It also omits the parts for programming the PICAXE, so some sort of external programming facilities need to be provided. The programming facility is either a pair of resistors if the output of the PC is RS-232, or a pair of inverters if a USB-TTL serial converter is used.

The connectors on the right side of the PCB provide the following facilities (although not all at once):
1) Up to four on/off outputs (some pwm modulated for LED brightness control, some can be used as inputs)
2) One PIR input
3) One hobby servo output)
4) 5V Power input
5) PICAXE programming pins (minus the signal conditioning components).

I haven't decided if I'm going to have PCBs fabricated, especially since a few other members of the forum might give me a hard time (in private, usually) for becoming distracted from Christmas display projects).
 

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FWIW, I've put this project on the back-burner even though I've ordered PCBs. It's more of a halloween thing than a Christmas thing. It was originally meant as a (somewhat expensive) programmable 555 replacement, and sort of grew out of control.
 
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