# Symmetric Line Follower Robot ## Description Two-channel symmetric line follower robot, dual CNY70 sensor front-end with mirrored 2N2222A motor drive stages and central 8V battery input ## Project Details - **Owner:** emanuelbueno - **Created:** 3/27/2026 - **Last Updated:** 4/6/2026 - **Visibility:** Public ## Key Components ### BT1 — [PJ-037A](https://www.flux.ai/vasy_skral/pj-037a~6cq.md) - Role: Power Input - Implementation Details: Place on board centerline at rear edge to balance battery wiring and split left/right power distribution evenly. - Package: Barrel_Jack_2Pin - Manufacturer Name: CUI Devices - Part Type: Connector - Role Details: Central 8V battery input to VCC and GND - Datasheet URL: https://www.cuidevices.com/product/resource/pj-037a.pdf - Manufacturer Part Number: PJ-037A **Pins:** - Center pin [pin 1] - Terminal [pin 2] ### D1 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md) - Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf - Role Details: Upper motor flyback diode across DCF1 - Manufacturer Part Number: 1N4007RLG - Manufacturer Name: onsemi - License: https://creativecommons.org/licenses/by/4.0/ - Role: Flyback Protection - Part Type: Diode - Package: DO-41 **Pins:** - anode [pin 2] - cathode [pin 1] ### D2 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg~07j.md) - Part Type: Diode - Manufacturer Name: onsemi - License: https://creativecommons.org/licenses/by/4.0/ - Package: DO-41 - Manufacturer Part Number: 1N4007RLG - Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf - Role: Flyback Protection - Role Details: Lower motor flyback diode across DCF2 **Pins:** - anode [pin 2] - cathode [pin 1] ### DCF1 — [DC Motor N20](https://www.flux.ai/ricetaco2/dc-motor-n20~qy.md) - Role Details: Upper mirrored N20 motor, positive to VCC and negative to Q1 collector - Implementation Details: Place near left edge with short high-current path to Q1; mirror DCF2 position and connector exit. - Role: Motor Load - Package: Motor_N20 **Pins:** - - [pin 2] - + [pin 1] ### DCF2 — [DC Motor N20](https://www.flux.ai/ricetaco2/dc-motor-n20~qy.md) - Package: Motor_N20 - Role Details: Lower mirrored N20 motor, positive to VCC and negative to Q3 collector - Implementation Details: Place near right edge with short high-current path to Q4; mirror DCF1 position and connector exit. - Role: Motor Load **Pins:** - - [pin 2] - + [pin 1] ### Q1 — [2N2222A](https://www.flux.ai/lcsc/2n2222a~00rk.md) - Frequency: 250MHz - JLCPCB Part Class: Extended Part - Role Details: Upper mirrored motor transistor for DCF1, low-side switch - Manufacturer Name: ST(先科) - Role: Motor Driver - Mount: Through Hole - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1809200018_ST-Semtech-2N2222A_C118536.pdf - Product Info Url: https://lcsc.com/product-detail/Transistors-NPN-PNP_2N2222_C118536.html - Package: TO-92-3_L4.9-W3.7-P1.27-L - Package or Case Code: TO-92-3_L4.9-W3.7-P1.27-L - LCSC Part Number: C118536 - Manufacturer Part Number: 2N2222A - Part Type: Transistors/Thyristors/Bipolar (BJT) - Transistor Type: NPN - Compliance: RoHS - Implementation Details: Mirror with Q4 across board centerline; keep same rotation class and edge distance. **Pins:** - B [pin 2] - C [pin 3] - E [pin 1] ### Q3 — [2N2222A](https://www.flux.ai/lcsc/2n2222a~00rk.md) - LCSC Part Number: C118536 - Package or Case Code: TO-92-3_L4.9-W3.7-P1.27-L - Product Info Url: https://lcsc.com/product-detail/Transistors-NPN-PNP_2N2222_C118536.html - Compliance: RoHS - Role Details: Lower mirrored motor transistor for DCF2, low-side switch - Transistor Type: NPN - Manufacturer Part Number: 2N2222A - Part Type: Transistors/Thyristors/Bipolar (BJT) - Manufacturer Name: ST(先科) - Package: TO-92-3_L4.9-W3.7-P1.27-L - Role: Sensor Driver - JLCPCB Part Class: Extended Part - Frequency: 250MHz - Implementation Details: Mirror with Q2 across board centerline; keep same rotation class and sensor-path proximity. - Mount: Through Hole - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1809200018_ST-Semtech-2N2222A_C118536.pdf **Pins:** - B [pin 2] - C [pin 3] - E [pin 1] ### U1 — [CNY70](https://www.flux.ai/lcsc/cny70~xkl.md) - Part Type: Reflective Optical Interrupters - Role: Reflective Sensor - JLCPCB Part Class: Extended Part - Mount: Through Hole - Package or Case Code: OPTO-TH_CNY70 - Manufacturer Name: VISHAY(威世) - Manufacturer Part Number: CNY70 - Implementation Details: Place at front board edge on left half; mirror U3 exactly relative to centerline. - Role Details: Upper mirrored line sensor - LCSC Part Number: C145423 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410121757_Vishay-Intertech-CNY70_C145423.pdf - Product Info Url: https://lcsc.com/product-detail/Sensors_VISHAY_CNY70_CNY70_C145423.html - Package: OPTO-TH_CNY70 **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U2 — [LTL-307EE](https://www.flux.ai/vasy_skral/ltl-307ee~a2.md) - Mount: Through Hole - Manufacturer Name: Lite-On Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/1153/LTL-307EE.pdf - Part Type: LED - Role Details: Lower mirrored indicator LED - Role: Indicator - Manufacturer Part Number: LTL-307EE - Implementation Details: Mirror with U5 using equal inset from centerline and same LED polarity orientation. - Package: LED_D5.0mm **Pins:** - A [pin 2] - K [pin 1] ### U3 — [CNY70](https://www.flux.ai/lcsc/cny70~xkl.md) - Mount: Through Hole - Package: OPTO-TH_CNY70 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410121757_Vishay-Intertech-CNY70_C145423.pdf - Product Info Url: https://lcsc.com/product-detail/Sensors_VISHAY_CNY70_CNY70_C145423.html - LCSC Part Number: C145423 - JLCPCB Part Class: Extended Part - Part Type: Reflective Optical Interrupters - Role: Reflective Sensor - Role Details: Lower mirrored line sensor - Package or Case Code: OPTO-TH_CNY70 - Manufacturer Name: VISHAY(威世) - Manufacturer Part Number: CNY70 - Implementation Details: Place at front board edge on right half; mirror U1 exactly relative to centerline. **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U5 — [LTL-307EE](https://www.flux.ai/vasy_skral/ltl-307ee~a2.md) - Manufacturer Part Number: LTL-307EE - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/1153/LTL-307EE.pdf - Part Type: LED - Role: Indicator - Implementation Details: Mirror with U2 using equal inset from centerline and same LED polarity orientation. - Role Details: Upper mirrored indicator LED - License: https://creativecommons.org/licenses/by/4.0/ - Mount: Through Hole - Package: LED_D5.0mm - Manufacturer Name: Lite-On Inc. **Pins:** - A [pin 2] - K [pin 1] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/emanuelbueno/symmetric-line-follower-robot~2f](https://www.flux.ai/emanuelbueno/symmetric-line-follower-robot~2f).* --- *Generated from [https://www.flux.ai/emanuelbueno/symmetric-line-follower-robot~2f](https://www.flux.ai/emanuelbueno/symmetric-line-follower-robot~2f)*