Big_P Big_p
Professional
I can take absolutely no credit for the circuit design, it has been around for ages. I first saw something similar when I was working in arcades 20 years ago. I saw someone selling something similar in Japan about 10 years ago and I have seen a few versions on here over the years. The idea of this one was to get it small enough to fit inline with the buttons under the control panel and cheap enough that you could do a number of cabs in one go. This is not for active auto fire with rates linked to the sync, there is no atmega128, thank god as I am sick of working with these guys, no frills, just simple inline passive auto fire.
Caveats are that I have not actually built the gerbers yet, Ill let you know when I get around to it, but it worked on a breadboard. On the breadboard there is a slight delay every second or so, which I kind of like, no voltage required it runs off the GND terminal and existing voltages. I used JST XH headers at each end because I dont like soldering wires to a PCB. Pin 1 of the JAMMA side takes a GND from the JAMMA harness, Pin 2 is left blank, while both pin 1 and 2 of the button side go the the buttons you want to auto fire GND pin, Pin 1 to one and Pin 2 to a second button if you want 2. The idea being that 1 device can do 1 cab with 2 buttons, 1 for p1 and 1 for p2 being auto fired. The pot has a knob and adjusts the rate of fire and the switch turns auto fire on and off on both sides, easy right. The whole board is about 3.5x2.5cm and when I have built some I will design a 3d printed box for them to go in. I have had this sitting around for ages and figured someone may be able to put one to use. I am trying to get some projects off the bench early in the new year so there is room for some new stuff. I have cleaned the gerbers up as much as I could be bothered there is still plenty of optimisation that could be done but over the last week I have managed to get it to a stage I happy to let someone look at. Oh the name, I was not feeling very inventive so it got the name it has had on the bench for the past year or so, Small Passive Pew-Pew Device, SPPD.
A few things I forgot, the switch side xh goes to harness the other side to the buttons.
BOM
U1 - 74HC04 Hex Inverter SOIC-14
SW1 - JS202011CQN Switch
RV1 - 10k ohm 3386P-1-104TLF Bourne's Trimpot
R1 - 0805 1k omh Resistor
C1 - 0805 100uf Capacitor
C2 - 0805 470nf Capacitor
J1, J2 - JST XH Horizontal header
Caveats are that I have not actually built the gerbers yet, Ill let you know when I get around to it, but it worked on a breadboard. On the breadboard there is a slight delay every second or so, which I kind of like, no voltage required it runs off the GND terminal and existing voltages. I used JST XH headers at each end because I dont like soldering wires to a PCB. Pin 1 of the JAMMA side takes a GND from the JAMMA harness, Pin 2 is left blank, while both pin 1 and 2 of the button side go the the buttons you want to auto fire GND pin, Pin 1 to one and Pin 2 to a second button if you want 2. The idea being that 1 device can do 1 cab with 2 buttons, 1 for p1 and 1 for p2 being auto fired. The pot has a knob and adjusts the rate of fire and the switch turns auto fire on and off on both sides, easy right. The whole board is about 3.5x2.5cm and when I have built some I will design a 3d printed box for them to go in. I have had this sitting around for ages and figured someone may be able to put one to use. I am trying to get some projects off the bench early in the new year so there is room for some new stuff. I have cleaned the gerbers up as much as I could be bothered there is still plenty of optimisation that could be done but over the last week I have managed to get it to a stage I happy to let someone look at. Oh the name, I was not feeling very inventive so it got the name it has had on the bench for the past year or so, Small Passive Pew-Pew Device, SPPD.
A few things I forgot, the switch side xh goes to harness the other side to the buttons.
BOM
U1 - 74HC04 Hex Inverter SOIC-14
SW1 - JS202011CQN Switch
RV1 - 10k ohm 3386P-1-104TLF Bourne's Trimpot
R1 - 0805 1k omh Resistor
C1 - 0805 100uf Capacitor
C2 - 0805 470nf Capacitor
J1, J2 - JST XH Horizontal header
ENJOY.Attachments
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