# 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:** 4/11/2026 - **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~a2.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: LTL-307EE - Role Details: Visible indication of logic power or robot status - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/1153/LTL-307EE.pdf - Package: 5mm THT - Manufacturer Name: Lite-On Inc. - Role: Status LED - Part Type: LED **Pins:** - A [pin 2] - K [pin 1] ### J1 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Current Rating: 24A - Part Type: Screw terminal - Role Details: 2-pin screw terminal for battery or adapter input - Role: Power Input - Connector Gender: Female - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Manufacturer Part Number: KF128-5.08-2P-AA - 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 - LCSC Part Number: C474952 - JLCPCB Part Class: Extended Part - Connector Pitch: 5.08mm - Connector Rows: 1 - Connector Positions: 2 - Operating Temperature: -40℃~+105℃ - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Manufacturer Name: KEFA(科发) - Connector Type: Screw terminal **Pins:** - 1 [pin 1] - 2 [pin 2] ### J2 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Connector Rows: 1 - Connector Pitch: 5.08mm - Package: Through Hole - JLCPCB Part Class: Extended Part - Connector Type: Screw terminal - Manufacturer Name: KEFA(科发) - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Operating Temperature: -40℃~+105℃ - Connector Positions: 2 - Current Rating: 24A - Part Type: Screw terminal - Role Details: 2-pin left motor screw terminal - LCSC Part Number: C474952 - Role: Motor Output - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Manufacturer Part Number: KF128-5.08-2P-AA - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Connector Gender: Female **Pins:** - 1 [pin 1] - 2 [pin 2] ### J3 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa~0pbi.md) - Role: Motor Output - JLCPCB Part Class: Extended Part - Connector Pitch: 5.08mm - Connector Rows: 1 - Operating Temperature: -40℃~+105℃ - Connector Positions: 2 - Role Details: 2-pin right motor screw terminal - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Manufacturer Name: KEFA(科发) - Connector Type: Screw terminal - Part Type: Screw terminal - Current Rating: 24A - Connector Gender: Female - Package: Through Hole - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html - Manufacturer Part Number: KF128-5.08-2P-AA - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - LCSC Part Number: C474952 **Pins:** - 1 [pin 1] - 2 [pin 2] ### J4 — [AVR-ISP-6](https://www.flux.ai/vasy_skral/avr-isp-6~ry.md) - Manufacturer Name: Würth Elektronik - Part Type: Connector - Datasheet URL: https://www.we-online.com/catalog/datasheet/61200621621.pdf - Manufacturer Part Number: 61200621621 - Role Details: 6-pin AVR ISP header for firmware upload and debug - Role: Programming Header - Package: 2.54mm Through Hole - Exclude from BOM: false **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~4u.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role: Reset Switch - Package: Through Hole - Role Details: Momentary button that pulls reset line low - Part Type: Switch **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~4u.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Switch - Role Details: Momentary start or mode input for competition control - Role: User 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] ### U1 — [ATMEGA328P-PU](https://www.flux.ai/adrian95/atmega328p-pu~6cd.md) - Package: PDIP-28 - Part Type: Microcontroller - Manufacturer Name: Microchip - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: ATMEGA328P-PU - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/ATmega48A-PA-88A-PA-168A-PA-328-P-DS-DS40002061B.pdf - Role Details: 5 V through-hole controller for robot decision logic, sensor reading, motor control, buttons, LEDs, and debug - Role: Microcontroller **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~9wp.md) - Symbol Style: Parametric - Package: DIP-16 - Manufacturer Name: STMicroelectronics - License: https://creativecommons.org/licenses/by/4.0/ - Role: Motor Driver - Part Type: Integrated Circuit - 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 - Role Details: Dual H-bridge for left and right DC motors with separate logic and motor supply rails - Manufacturer Part Number: L293D **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~wo3.md) - Role: Voltage Regulator - Manufacturer Name: Texas Instruments - Package: TO-220-3 - Role Details: Generates 5 V logic rail from external battery or adapter input - Part Type: Integrated Circuit - Datasheet URL: https://www.ti.com/lit/ds/symlink/lm340.pdf - Manufacturer Part Number: LM7805CT/NOPB - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - GND [pin 2] - VI [pin 1] - VO [pin 3] ### U4 — [TCRT5000](https://www.flux.ai/lcsc/tcrt5000~5b7q.md) - Manufacturer Part Number: TCRT5000 - Role: Reflective Sensor - Manufacturer Name: VISHAY(威世) - JLCPCB Part Class: Extended Part - Package or Case Code: OPTO-TH_TCRT5000 - LCSC Part Number: C2984661 - Package: Leaded - Role Details: Left-side reflective IR sensor for path or edge detection **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U5 — [TCRT5000](https://www.flux.ai/lcsc/tcrt5000~5b7q.md) - Manufacturer Part Number: TCRT5000 - Role: Reflective Sensor - LCSC Part Number: C2984661 - Package or Case Code: OPTO-TH_TCRT5000 - Role Details: Right-side reflective IR sensor for path or edge detection - Package: Leaded - JLCPCB Part Class: Extended Part - 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~gm](https://www.flux.ai/kartik20052007/to-and-fro-memory-robot~gm).* --- *Generated from [https://www.flux.ai/kartik20052007/to-and-fro-memory-robot~gm](https://www.flux.ai/kartik20052007/to-and-fro-memory-robot~gm)*