2 layers30 × 42 mm
Copv2
swagprincess/coilonplug
Dwell converter/shaper for a stock ECU COP conversion on a Miata
31 partsGPL-3.0
2 layers26.3 × 33.4 mm
Coilonplugv3
swagprincess/coilonplugDwell converter/shaper for a stock ECU COP conversion on a Miata
- Size
- 26.3 × 33.4 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 32
- Nets
- 23
- Pads
- 77
- Tracks, vias
- 186, 59
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 10 Aug 2025
- Updated
- 29 Jun 2026
Overview
Coilonplugv3 is an open-source printed circuit board by swagprincess, from the swagprincess/coilonplug repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 26.3 × 33.4 mm with 32 parts on 23 nets, routed with 186 tracks and 59 vias.
It is built around the ATTINY84A-SSF, SN74LVC1G17DBVR and DMP3098LSD-13-VB. Its parts include 4 capacitors, 4 resistors, 4 ICs, 2 diodes and 1 transistor. It belongs with the AVR (ATmega, ATtiny) boards of this library.
Main components
3
ATTINY84A-SSF
SOIC-14-40℃~+125℃ 1.8V~5.5V 10bit 12 20MHz 512Byte 8 Bit 8KB AVR Built-in FLASH SOIC-14 Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
SN74LVC1G17DBVR
SOT-23-5-40℃~+125℃ 1 1 1.2V、1.9V、2.3V、2.4V 1.65V~5.5V 100mV、300mV、400mV、550mV 10uA 32mA 32mA 74LVC 8.3ns@5V,50pF SOT-23-5 Logic Gates ROHSTECH PUBLICLogic Gates
DMP3098LSD-13-VB
SO-8MOSFETsVBsemi Elec
README
README.mdDwell converter board
This board lets you use a Toyota/Audi/etc "coil on plug" ignition system with the stock ecu in a Mazda MX5/Miata (1989-2005).
The board will take in a variable dwell signal for the stock coilpack and output a (falling edge synchronised) stable, adjustable dwell pulse.
Current setting is 70 "ticks" of TIMER1, around 2.2ms, correct for Toyota COP's at running voltages (should be good for Audi R8 coils too).
Written in C for an AtTiny84A.
Parts
32| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | TestPoint | TestPoint:TestPoint_Pad_2.5x2.5mm | GND1, GND2, GND3, GND4, GND5, IGN1, IGN1/4, IGN2, IGN2/3, IGN3, IGN4, VCC1, VCC2, VCC3, VCC4, VCC5 |
| 4 | 10k | Resistor_SMD:R_0603_1608Metric | R1, R2, R3, R4 |
| 2 | 100n | Capacitor_SMD:C_0603_1608Metric | C1, C3 |
| 2 | MM3Zxx | Diode_SMD:D_SOD-323F | D1, D2 |
| 2 | SN74LVC1G17DBVR | Package_TO_SOT_SMD:SOT-23-5 | U2, U3 |
| 1 | 10u | Capacitor_SMD:C_0603_1608Metric | C4 |
| 1 | 330n | Capacitor_SMD:C_0603_1608Metric | C2 |
| 1 | ATtiny84A-SS | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U1 |
| 1 | Conn_02x03_Counter_Clockwise | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical | J1 |
| 1 | DMP3098LSD-13 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | Q1 |
| 1 | L78L05_SOT89 | Package_TO_SOT_SMD:SOT-89-3 | U4 |
More from swagprincess/coilonplug
1Similar boards
- 2 layers168 × 44 mm
- 4 layers158 × 68 mm
DronePCB
nickzentmayer/EE300W-R6Drone
Repository containing all code and CAD design files for EE300W project SP26
167 parts - 4 layers64 × 28.8 mm
- 2 layers133.4 × 50.8 mm
- 2 layers99.4 × 38.6 mm
Slider driver
mage0r/RSA0N11M9A0J_motorised_slider
This is a H-bridge driver board for the RSA0N11M9A0J motorised Slider. It uses a L9110 and capacitive sensor.
38 parts7 - 4 layers85 × 56 mm
- 2 layers13.6 × 23.2 mm
Trinkle
mage0r/trinkle
A breakout board for the ATTiny84. Sometimes a Trinket just won't do...
12 parts2 - 2 layers100 × 50 mm
Moba block stelle
hpbock/moba-bockstelle
Ein Blockstellenmodul für analoge Modellbahnen zur Ansteuerung von Lichtsignalen, Zugbeeinflussung und Belegtmeldung für Loconet-T.
88 parts1
Questions
How big is the Coilonplugv3 PCB?
It measures 26.3 × 33.4 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Coilonplugv3 use?
32 parts, built around the ATTINY84A-SSF, SN74LVC1G17DBVR and DMP3098LSD-13-VB. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Coilonplugv3 KiCad files?
From the swagprincess/coilonplug repository on GitHub, at the commit this page was made from: the board is kicad/v3/coilonplugv3.kicad_pcb and its schematic kicad/v2/copv2.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Coilonplugv3 design in my own project?
Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).