# Smart CDI Motorcycle ECU
## Description
High-performance ESP32-based smart CDI / motorcycle ECU with automotive 12V transient protection, flyback HV capacitor charging, isolated SCR firing, VR pickup input, analog sensors, and auxiliary low-side outputs.
## Project Details
- **Owner:** eclyp
- **Created:** 6/21/2026
- **Last Updated:** 6/22/2026
- **Visibility:** Public
- **Stars:** 1
- **Copies:** 1
## Key Components
### D3 — [US1M](https://www.flux.ai/lcsc/us1m~iv7a.md)
- Manufacturer Name: MDD(辰达半导体)
- Manufacturer Part Number: US1M
- Role: Rectification
- JLCPCB Part Class: Basic Part
- Part Type: Diodes - Fast Recovery Rectifiers
- Max Reverse Voltage: 60V
- Package or Case Code: SMA_L4.4-W2.8-LS5.4-RD
- Forward Voltage: 0.45V-0.50V
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2407101111_MDD-Microdiode-Semiconductor-US1M_C412437.pdf
- LCSC Part Number: C412437
- Diode Type: Schottky Diode
- Product Info Url: https://lcsc.com/product-detail/Diodes-Rectifiers-Fast-Recovery_MDD-Microdiode-Electronics-US1MG_C412437.html
**Pins:**
- A [pin 2]
- C [pin 1]
### D4 — [US1M](https://www.flux.ai/lcsc/us1m~iv7a.md)
- Manufacturer Part Number: US1M
- Manufacturer Name: MDD(辰达半导体)
- Part Type: Diodes - Fast Recovery Rectifiers
- JLCPCB Part Class: Basic Part
- Role: Rectification
- Forward Voltage: 0.45V-0.50V
- Package or Case Code: SMA_L4.4-W2.8-LS5.4-RD
- Max Reverse Voltage: 60V
- Product Info Url: https://lcsc.com/product-detail/Diodes-Rectifiers-Fast-Recovery_MDD-Microdiode-Electronics-US1MG_C412437.html
- LCSC Part Number: C412437
- Diode Type: Schottky Diode
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2407101111_MDD-Microdiode-Semiconductor-US1M_C412437.pdf
**Pins:**
- A [pin 2]
- C [pin 1]
### D5 — [RS1M](https://www.flux.ai/lcsc/rs1m~s0q.md)
- Part Type: Diodes - Fast Recovery Rectifiers
- LCSC Part Number: C720785
- Package or Case Code: D-FLAT_L4.3-W2.6-LS5.3-RD
- Manufacturer Part Number: RS1M
- Product Info Url: https://lcsc.com/product-detail/Diodes-Rectifiers-Fast-Recovery_Changzhou-Starsea-Elec-RS1M_C720785.html
- JLCPCB Part Class: Extended Part
- Role: Flyback / Freewheeling
- Manufacturer Name: 星海
- Datasheet URL: https://assets.lcsc.com/datasheet/szlcsc/Download-ISO9001-Certification.pdf
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D6 — [RS1M](https://www.flux.ai/lcsc/rs1m~s0q.md)
- Part Type: Diodes - Fast Recovery Rectifiers
- Manufacturer Part Number: RS1M
- LCSC Part Number: C720785
- Role: Flyback / Freewheeling
- Package or Case Code: D-FLAT_L4.3-W2.6-LS5.3-RD
- Manufacturer Name: 星海
- Datasheet URL: https://assets.lcsc.com/datasheet/szlcsc/Download-ISO9001-Certification.pdf
- Product Info Url: https://lcsc.com/product-detail/Diodes-Rectifiers-Fast-Recovery_Changzhou-Starsea-Elec-RS1M_C720785.html
- JLCPCB Part Class: Extended Part
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D7 — [BZT52C3V3](https://www.flux.ai/lcsc/bzt52c3v3~zj44.md)
- Product Info Url: https://lcsc.com/product-detail/Others_SK-BZT52C3V3_C216707.html
- Part Type: Zener Diodes
- LCSC Part Number: C216707
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Shikues-BZT52C3V3_C216707.pdf
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: BZT52C3V3
- Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD
- Manufacturer Name: SHIKUES(时科)
- Role: Clamping
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### D8 — [BZT52C3V3](https://www.flux.ai/lcsc/bzt52c3v3~zj44.md)
- LCSC Part Number: C216707
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Shikues-BZT52C3V3_C216707.pdf
- JLCPCB Part Class: Extended Part
- Manufacturer Part Number: BZT52C3V3
- Package or Case Code: SOD-123_L2.7-W1.6-LS3.7-RD
- Manufacturer Name: SHIKUES(时科)
- Role: Clamping
- Product Info Url: https://lcsc.com/product-detail/Others_SK-BZT52C3V3_C216707.html
- Part Type: Zener Diodes
**Pins:**
- 1 [pin 1]
- 2 [pin 2]
### PAD_3V3_GND — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Name: Keystone
- Role: Connector
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Part Type: Connectors
- Manufacturer Part Number: 1040
- Role Details: Single through-hole solder pad for 3.3V input GND.
**Pins:**
- TP [pin TP]
### PAD_3V3_IN — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role Details: Single through-hole solder pad for 3V3_IN.
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
- Part Type: Connectors
- Manufacturer Name: Keystone
- Role: Connector
**Pins:**
- TP [pin TP]
### PAD_5V_GND — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
- Role: Connector
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for 5V input GND.
**Pins:**
- TP [pin TP]
### PAD_5V_IN — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role: Connector
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for 5V_IN.
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
**Pins:**
- TP [pin TP]
### PAD_5V_SENSOR — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role Details: Single through-hole solder pad for 5V_IN / sensor 5V.
- Manufacturer Name: Keystone
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Part Type: Connectors
- Role: Connector
- Manufacturer Part Number: 1040
**Pins:**
- TP [pin TP]
### PAD_AC_IN — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Part Type: Connectors
- Role Details: Single through-hole solder pad for AC_IN_HV input.
- Manufacturer Part Number: 1040
- Role: Connector
- Manufacturer Name: Keystone
**Pins:**
- TP [pin TP]
### PAD_AC_RET — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for HV return / GND.
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Part Type: Connectors
- Role: Connector
- Manufacturer Part Number: 1040
**Pins:**
- TP [pin TP]
### PAD_AUX_GND — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role: Connector
- Role Details: Single through-hole solder pad for AUX outputs GND.
- Manufacturer Name: Keystone
- Manufacturer Part Number: 1040
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
**Pins:**
- TP [pin TP]
### PAD_AUX1 — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role: Connector
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for AUX1_OUT.
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Part Type: Connectors
- Manufacturer Part Number: 1040
**Pins:**
- TP [pin TP]
### PAD_AUX2 — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Name: Keystone
- Role: Connector
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Role Details: Single through-hole solder pad for AUX2_OUT.
- Manufacturer Part Number: 1040
- Part Type: Connectors
**Pins:**
- TP [pin TP]
### PAD_SPARK — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Part Number: 1040
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Role: Connector
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for SPARK_OUT.
**Pins:**
- TP [pin TP]
### PAD_SPARK_RET — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Name: Keystone
- Role: Connector
- Role Details: Single through-hole solder pad for SPARK return / GND.
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Part Type: Connectors
- Manufacturer Part Number: 1040
**Pins:**
- TP [pin TP]
### PAD_TEMP — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role: Connector
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for TEMP_IN.
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
**Pins:**
- TP [pin TP]
### PAD_TEMP_GND — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Name: Keystone
- Role: Connector
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
- Role Details: Single through-hole solder pad for sensor GND.
**Pins:**
- TP [pin TP]
### PAD_TPS — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Part Number: 1040
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Role: Connector
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for TPS_IN.
**Pins:**
- TP [pin TP]
### PAD_TPS_GND — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
- Part Type: Connectors
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for TPS GND.
- Role: Connector
**Pins:**
- TP [pin TP]
### PAD_VR_NEG — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Name: Keystone
- Role: Connector
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
- Role Details: Single through-hole solder pad for VR_SIGNAL_NEG.
**Pins:**
- TP [pin TP]
### PAD_VR_POS — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Manufacturer Part Number: 1040
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Name: Keystone
- Role Details: Single through-hole solder pad for VR_SIGNAL_POS.
- Role: Connector
**Pins:**
- TP [pin TP]
### Q1 — [2N6509G](https://www.flux.ai/adrian95/2n6509g~bsj.md)
- Role: CDI Discharge SCR
- Manufacturer Name: Nexperia / workshop-supplied equivalent
- Part Type: Thyristors
- Allow Substitutes: No
- Role Details: Workshop-approved BT151-600R TO-220 SCR for CDI discharge; manual-approved safety-critical part, validate pinout A/K/G and thermal mounting before power testing.
- Datasheet URL: https://www.mouser.com/datasheet/2/240/media-3319470.pdf
- Manufacturer Part Number: BT151-600R
- License: https://creativecommons.org/licenses/by/4.0/
- Package or Case Code: TO-220
**Pins:**
- A [pin 2]
- G [pin 3]
- K [pin 1]
### Q2 — [AO3400A](https://www.flux.ai/lcsc/ao3400a~e5y2.md)
- Product Info Url: https://lcsc.com/product-detail/Others_Youtai-Semiconductor-Co-Ltd-AO3400A-5-8A_C347475.html
- LCSC Part Number: C347475
- Transistor Type: N-channel MOSFET
- Continuous Drain Current: 5.7A
- Manufacturer Part Number: AO3400A
- Manufacturer Name: UMW(友台半导体)
- Drain to Source Voltage: 30V
- Part Type: MOSFETs
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010301_UMW-Youtai-Semiconductor-Co---Ltd--AO3400A_C347475.pdf
- Operating Temperature: -55 ~ +150℃
- Power: 1.4W
- JLCPCB Part Class: Extended Part
- Role: Low-side Switch
- Package or Case Code: SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR
**Pins:**
- D [pin 3]
- G [pin 1]
- S [pin 2]
### Q3 — [AO3400A](https://www.flux.ai/lcsc/ao3400a~e5y2.md)
- Product Info Url: https://lcsc.com/product-detail/Others_Youtai-Semiconductor-Co-Ltd-AO3400A-5-8A_C347475.html
- Transistor Type: N-channel MOSFET
- LCSC Part Number: C347475
- Manufacturer Name: UMW(友台半导体)
- Manufacturer Part Number: AO3400A
- Continuous Drain Current: 5.7A
- Part Type: MOSFETs
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010301_UMW-Youtai-Semiconductor-Co---Ltd--AO3400A_C347475.pdf
- Drain to Source Voltage: 30V
- Power: 1.4W
- Operating Temperature: -55 ~ +150℃
- Role: Low-side Switch
- JLCPCB Part Class: Extended Part
- Package or Case Code: SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR
**Pins:**
- D [pin 3]
- G [pin 1]
- S [pin 2]
### TP2 — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Role Details: Small through-hole pad/hole for soldering or probing 5V_OUT.
- Part Type: Connectors
- Manufacturer Part Number: 1040
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Role: Wire Solder Test Point
- Manufacturer Name: Keystone
**Pins:**
- TP [pin TP]
### TP5 — [1040](https://www.flux.ai/cherepanyadima/1040~lm.md)
- Part Type: Connectors
- Datasheet URL: https://www.keyelco.com/userAssets/file/K75p63.pdf
- Manufacturer Part Number: 1040
- Role: Wire Solder Test Point
- Manufacturer Name: Keystone
- Role Details: Small through-hole pad/hole for soldering or probing SCR_FIRE_GPIO27.
**Pins:**
- TP [pin TP]
### U1 — [ESP32-WROOM-32UE-N4](https://www.flux.ai/lcsc/esp32-wroom-32ue-n4~33po.md)
- LCSC Part Number: C2934568
- Role: MCU
- JLCPCB Part Class: Extended Part
- Manufacturer Name: ESPRESSIF(乐鑫)
- Part Type: WIFI Modules
- Manufacturer Part Number: ESP32-WROOM-32UE-N4
- Package or Case Code: WIFI-SMD_ESP32-WROOM-32UE-A
**Pins:**
- 3V3 [pin 2]
- EN [pin 3]
- GND [pin 15]
- GND [pin 38]
- GND [pin 39]
- GND [pin 1]
- IO0 [pin 25]
- IO12 [pin 14]
- IO13 [pin 16]
- IO14 [pin 13]
- IO15 [pin 23]
- IO16 [pin 27]
- IO17 [pin 28]
- IO18 [pin 30]
- IO19 [pin 31]
- IO2 [pin 24]
- IO21 [pin 33]
- IO22 [pin 36]
- IO23 [pin 37]
- IO25 [pin 10]
- IO26 [pin 11]
- IO27 [pin 12]
- IO32 [pin 8]
- IO33 [pin 9]
- IO34 [pin 6]
- IO35 [pin 7]
- IO4 [pin 26]
- IO5 [pin 29]
- NC [pin 20]
- NC [pin 17]
- NC [pin 21]
- NC [pin 18]
- NC [pin 19]
- NC [pin 22]
- NC [pin 32]
- RXD0 [pin 34]
- SENSOR_VN [pin 5]
- SENSOR_VP [pin 4]
- TXD0 [pin 35]
### U5 — [MAX9924UAUB+T](https://www.flux.ai/adrian95/max9924uaubplust~oxz.md)
- Datasheet URL: https://datasheets.maximintegrated.com/en/ds/MAX9924-MAX9927.pdf
- Role: VR Sensor Interface
- Part Type: Integrated Circuit
- Allow Substitutes: No
- License: https://creativecommons.org/licenses/by/4.0/
- Package or Case Code: SOP50P490X110-10N
- Role Details: MAX9924 VR sensor interface is a manual-approved safety-critical BOM item; do not auto-substitute without redesign, datasheet review, and bench validation.
- Manufacturer Name: Analog Devices
- Manufacturer Part Number: MAX9924UAUB+T
**Pins:**
- BIAS [pin 4]
- COUT [pin 7]
- EXT [pin 8]
- GND [pin 5]
- IN- [pin 2]
- IN+ [pin 1]
- INT_THRS [pin 9]
- N.C. [pin 3]
- VCC [pin 10]
- ZERO_EN [pin 6]
### U6 — [MOC3021S-TA1](https://www.flux.ai/lcsc/moc3021s-ta1~o2en.md)
- Role: Optoisolated SCR Trigger
- Manufacturer Part Number: MOC3021S-TA1
- LCSC Part Number: C115465
- Manufacturer Name: LITEON(光宝)
- Package or Case Code: SMD-6_L7.3-W6.5-P2.54-LS10.2-BL
- Product Info Url: https://lcsc.com/product-detail/SMD-Optocouplers_MOC3021S-TA1_C115465.html
- Max Forward Current: 50mA
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Lite-On-MOC3021S-TA1_C115465.pdf
- Forward Voltage Drop: 1.2V
- JLCPCB Part Class: Extended Part
- Max Reverse Voltage: 5V
- Part Type: Optocouplers - Thyristor Signal Output
**Pins:**
- AN [pin 1]
- CAT [pin 2]
- MT [pin 4]
- MT [pin 6]
- NC [pin 3]
- SUB [pin 5]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/eclyp/smart-cdi-motorcycle-ecu~db](https://www.flux.ai/eclyp/smart-cdi-motorcycle-ecu~db).*
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*Generated from [https://www.flux.ai/eclyp/smart-cdi-motorcycle-ecu~db](https://www.flux.ai/eclyp/smart-cdi-motorcycle-ecu~db)*