# To and Fro Memory Robot ## Description Competition PCB for a to and fro memory robot using through-hole components only. Target layout is maximum 120 mm x 70 mm, 2-layer maximum with top-layer routing only, 0.5 mm trace width minimum design intent, 0.3 mm clearance minimum, restricted solder mask outside the board center, and manufacturing freeze before 15 April 2026. Planned architecture uses a simple 5 V control and drive system with sensor inputs, memory/control logic, motor-driver stage, user controls, and edge-access debug/test points. ## Project Details - **Owner:** kartik20052007 - **Created:** 3/28/2026 - **Last Updated:** 3/28/2026 - **Visibility:** Public - **Compliance:** College competition PCB rules - **Domain:** Educational Robotics Competition - **Implementation Details:** Board size <=120 mm x 70 mm; maximum 2 copper layers; route signals on top layer only; minimum trace width 0.5 mm; minimum clearance 0.3 mm; through-hole components only; solder mask restricted outside board center; freeze design before 15 April 2026. - **Manufacturing Quantity Target:** Prototype competition build ## Key Components ### D1 — [LTL-307EE](https://www.flux.ai/vasy_skral/ltl-307ee.md) - Role Details: Visible indication of logic power or robot status - Manufacturer Name: Lite-On Inc. - Manufacturer Part Number: LTL-307EE - License: https://creativecommons.org/licenses/by/4.0/ - Role: Status LED - Part Type: LED - Package: 5mm THT - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/1153/LTL-307EE.pdf **Pins:** - A [pin 2] - K [pin 1] ### J1 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa.md) - Manufacturer Name: KEFA(科发) - LCSC Part Number: C474952 - Operating Temperature: -40℃~+105℃ - Connector Rows: 1 - Current Rating: 24A - Role: Power Input - Package: Through Hole - Connector Type: Screw terminal - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Part Type: Screw terminal - Manufacturer Part Number: KF128-5.08-2P-AA - Connector Positions: 2 - JLCPCB Part Class: Extended Part - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Connector Gender: Female - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Connector Pitch: 5.08mm - Role Details: 2-pin screw terminal for battery or adapter input **Pins:** - 1 [pin 1] - 2 [pin 2] ### J2 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa.md) - Current Rating: 24A - Operating Temperature: -40℃~+105℃ - Connector Rows: 1 - LCSC Part Number: C474952 - Manufacturer Name: KEFA(科发) - Connector Pitch: 5.08mm - Role: Motor Output - Role Details: 2-pin left motor screw terminal - Connector Gender: Female - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Package: Through Hole - Manufacturer Part Number: KF128-5.08-2P-AA - Connector Positions: 2 - Part Type: Screw terminal - JLCPCB Part Class: Extended Part - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Connector Type: Screw terminal **Pins:** - 1 [pin 1] - 2 [pin 2] ### J3 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa.md) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Role: Motor Output - Connector Gender: Female - Connector Pitch: 5.08mm - Role Details: 2-pin right motor screw terminal - Connector Type: Screw terminal - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - JLCPCB Part Class: Extended Part - Connector Positions: 2 - Part Type: Screw terminal - Manufacturer Part Number: KF128-5.08-2P-AA - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Current Rating: 24A - LCSC Part Number: C474952 - Package: Through Hole - Manufacturer Name: KEFA(科发) - Connector Rows: 1 - Operating Temperature: -40℃~+105℃ **Pins:** - 1 [pin 1] - 2 [pin 2] ### J4 — [AVR-ISP-6](https://www.flux.ai/vasy_skral/avr-isp-6.md) - Part Type: Connector - Package: 2.54mm Through Hole - Manufacturer Part Number: 61200621621 - Role: Programming Header - Role Details: 6-pin AVR ISP header for firmware upload and debug - Exclude from BOM: false - Datasheet URL: https://www.we-online.com/catalog/datasheet/61200621621.pdf - Manufacturer Name: Würth Elektronik **Pins:** - Pin_1 [pin 1] - Pin_2 [pin 2] - Pin_3 [pin 3] - Pin_4 [pin 4] - Pin_5 [pin 5] - Pin_6 [pin 6] ### S1 — [SWITCH-PUSH-6mm-H5mm-4pin](https://www.flux.ai/baronunread/switch-push-6mm-h5mm-4pin.md) - Part Type: Switch - Role Details: Momentary button that pulls reset line low - License: https://creativecommons.org/licenses/by/4.0/ - Role: Reset Switch - Package: Through Hole **Pins:** - 1-1 [pin 1-1] - 1-2 [pin 1-2] - 2-1 [pin 2-1] - 2-2 [pin 2-2] ### S2 — [SWITCH-PUSH-6mm-H5mm-4pin](https://www.flux.ai/baronunread/switch-push-6mm-h5mm-4pin.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Switch - Role Details: Momentary start or mode input for competition control - Package: Through Hole - Role: User Switch **Pins:** - 1-1 [pin 1-1] - 1-2 [pin 1-2] - 2-1 [pin 2-1] - 2-2 [pin 2-2] ### U1 — [ATMEGA328P-PU](https://www.flux.ai/adrian95/atmega328p-pu.md) - Package: PDIP-28 - Manufacturer Part Number: ATMEGA328P-PU - Role: Microcontroller - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Microchip - Role Details: 5 V through-hole controller for robot decision logic, sensor reading, motor control, buttons, LEDs, and debug - Part Type: Microcontroller - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/ATmega48A-PA-88A-PA-168A-PA-328-P-DS-DS40002061B.pdf **Pins:** - ~RESET~/PC6 [pin 1] - AREF [pin 21] - AVCC [pin 20] - GND [pin 8] - GND [pin 22] - PB0 [pin 14] - PB1 [pin 15] - PB2 [pin 16] - PB3 [pin 17] - PB4 [pin 18] - PB5 [pin 19] - PC0 [pin 23] - PC1 [pin 24] - PC2 [pin 25] - PC3 [pin 26] - PC4 [pin 27] - PC5 [pin 28] - PD0 [pin 2] - PD1 [pin 3] - PD2 [pin 4] - PD3 [pin 5] - PD4 [pin 6] - PD5 [pin 11] - PD6 [pin 12] - PD7 [pin 13] - VCC [pin 7] - XTAL1/PB6 [pin 9] - XTAL2/PB7 [pin 10] ### U2 — [L293D](https://www.flux.ai/vasy_skral/l293d.md) - Role Details: Dual H-bridge for left and right DC motors with separate logic and motor supply rails - Symbol Style: Parametric - Datasheet URL: https://www.st.com/content/ccc/resource/technical/document/datasheet/04/ac/22/f9/20/5d/43/a1/CD00000059.pdf/files/CD00000059.pdf/jcr:content/translations/en.CD00000059.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Package: DIP-16 - Manufacturer Part Number: L293D - Part Type: Integrated Circuit - Manufacturer Name: STMicroelectronics - Role: Motor Driver **Pins:** - 1A [pin 2] - 1Y [pin 3] - 2A [pin 7] - 2Y [pin 6] - 3A [pin 10] - 3Y [pin 11] - 4A [pin 15] - 4Y [pin 14] - EN1,2 [pin 1] - EN3,4 [pin 9] - GND [pin 12] - GND [pin 5] - GND [pin 13] - GND [pin 4] - VCC1 [pin 16] - VCC2 [pin 8] ### U3 — [LM7805CT/NOPB](https://www.flux.ai/adrian95/lm7805ctnopb.md) - Manufacturer Name: Texas Instruments - Role Details: Generates 5 V logic rail from external battery or adapter input - Part Type: Integrated Circuit - Package: TO-220-3 - Manufacturer Part Number: LM7805CT/NOPB - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.ti.com/lit/ds/symlink/lm340.pdf - Role: Voltage Regulator **Pins:** - GND [pin 2] - VI [pin 1] - VO [pin 3] ### U4 — [TCRT5000](https://www.flux.ai/lcsc/tcrt5000.md) - Manufacturer Name: VISHAY(威世) - Manufacturer Part Number: TCRT5000 - JLCPCB Part Class: Extended Part - Role: Reflective Sensor - LCSC Part Number: C2984661 - Role Details: Left-side reflective IR sensor for path or edge detection - Package or Case Code: OPTO-TH_TCRT5000 - Package: Leaded **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U5 — [TCRT5000](https://www.flux.ai/lcsc/tcrt5000.md) - LCSC Part Number: C2984661 - JLCPCB Part Class: Extended Part - Role: Reflective Sensor - Package or Case Code: OPTO-TH_TCRT5000 - Package: Leaded - Role Details: Right-side reflective IR sensor for path or edge detection - Manufacturer Part Number: TCRT5000 - Manufacturer Name: VISHAY(威世) **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/kartik20052007/to-and-fro-memory-robot](https://www.flux.ai/kartik20052007/to-and-fro-memory-robot).* --- *Generated from [https://www.flux.ai/kartik20052007/to-and-fro-memory-robot](https://www.flux.ai/kartik20052007/to-and-fro-memory-robot)*