OpenBot (DIY body) parts list
Turns an Android phone into the brain of a cheap 3D printed four-wheel car for teaching driving policies and person following.
Educational kitsbeginner by Intel Labs (now the OpenBot community)
Exploded view
Tap any part to see where to buy it. Diagram is schematic, not to scale.
Every part you need
| Part | Qty | Spec | Where to buy |
|---|---|---|---|
| Arduino Nano microcontroller | 1 | ATmega328, 5V; clones work Reads the phone's commands over USB and drives the motors. | Arduino: EUR 27.20 single; official board, incl. VAT Amazon: check price Amazon: check price AliExpress: check price (unverified) single; BOM link |
| TT gearmotor with tire motors | 4 | Yellow plastic TT gearbox motors, one per wheel 4WD skid steer drive. | Amazon: check price AliExpress: check price (unverified) single; BOM link Adafruit: $2.95 single; 200 RPM motor only, 3 to 6V Adafruit: $1.50 single; wheel only |
| 18650 Li-ion cell power | 3 | 3 in series, about 9 to 12.6V; firmware battery thresholds assume this pack Powers motors and the Nano. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| 3x 18650 battery holder power | 1 | Series holder for three cells Holds the pack in the body. | Amazon: check price Amazon: check price AliExpress: check price (unverified) single; BOM link |
| USB OTG cable cable | 1 | Matches your phone's port (USB-C or micro-USB) to the Nano's Mini-B Links the phone (the robot's brain) to the Nano. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| Spring or rubber band mount | 1 | Any small spring or band Clamps the phone in the printed mount. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| M3x25 screw fastener | 16 | Motors and body; 8 hold the motors. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| M3 nut fastener | 16 | Pairs with the M3x25 screws. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| M3x5 screw fastener | 6 | Mounts the L298N board and small parts. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| Dupont jumper cables wiring | 1 | Assorted pack Wiring between Nano, driver and sensors. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| L298N dual H-bridge motor driver motor driver (DIY option) | 1 | Drives left and right motor pairs; the DIY wiring option. The custom PCB option replaces it Lets the 5V Nano switch the motor current. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| Resistors: 2x 150 ohm, 1x 20k, 1x 10k electronics (DIY option, optional) | 1 | 150 ohm for the LEDs; 20k and 10k form the battery voltage divider Lets the firmware read battery voltage and drive the indicator LEDs. | no verified seller yet |
| Speed sensor with encoder disk sensor (optional) | 2 | Slotted optical sensor; disks go on the two front motors Measures wheel speed. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| Ultrasonic distance sensor sensor (optional) | 1 | HC-SR04 type; swap the angled header for a straight one Simple obstacle distance. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| On/off switch switch (optional) | 1 | Small panel switch Cuts battery power. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| Orange LED 5 mm indicator (optional) | 2 | Turn signal indicators. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| OLED display display (optional) | 1 | Small I2C OLED Shows battery and speed readouts. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
| OpenBot custom PCB PCB option | 1 | Gerbers in the repo; order from a PCB fab Replaces most of the DIY wiring for cleaner or multiple builds. | no verified seller yet |
| Micro JST PH 2.0 cable PCB option | 5 | Pre-crimped PH 2.0 leads Connects motors and sensors to the custom PCB. | Amazon: check price AliExpress: check price (unverified) single; BOM link |
Quantities follow the official OpenBot (DIY body) docs: https://github.com/ob-f/OpenBot/blob/master/body/diy/README.md. "Unverified" prices come from search listings or older BOMs that we could not confirm on the seller's product page.
Kits (fewer orders, check what they leave out)
| Kit | Price | Includes | Leaves out | Buy |
|---|---|---|---|---|
| 4x TT motors and tires + 2x L298N + dupont cables combo Amazon (official BOM, alternative) | check price | Motors, tires, two L298N boards, jumper wires | Nano, batteries, printed body | Amazon: check price |
| Perseids DIY robot smart car chassis kit Amazon (official BOM, no 3D printer) | check price | Chassis, motors and wheels in place of the printed body | Electronics and a phone mount | Amazon: check price |
3D printed parts
Needed. Regular body needs a 240x150 mm bed; slim body fits 220x220 mm at 45 degrees; glueable body fits 150x140 mm. Also print the two phone mount parts. Without a printer, the BOM lists cheap car chassis kits instead. Files: https://github.com/ob-f/OpenBot/tree/master/body/diy/cad
Mistakes builders make
- You need a smartphone: it runs the neural networks and the app. Android is the main platform; an iOS app exists but has open control bugs (issue 505).
- Set the firmware to the DIY robot type and enable only the options you installed (voltage divider, sonar, indicators, OLED), or readings will be wrong.
- The firmware battery thresholds assume a 3S 18650 pack (9V low, 12.6V full); a different pack needs new values.
- The OLED shows the left wheel's RPM in the right slot in older firmware; the fix is a one-word change (issue 478).
- Put the encoder disks on the two front motors before mounting them if you plan to add speed sensors.
- The project moved from isl-org to ob-f on GitHub; older links still redirect.
FAQ
How much does it cost to build the OpenBot (DIY body)?
About $60 to $130 in parts at current prices, Required parts plus the L298N DIY option come to roughly $60 to $90 from Amazon or AliExpress; the optional sensors, switch, LEDs and OLED add $20 to $40. Excludes the smartphone, a 3D printer and filament, and shipping. Most links in the BOM are Amazon or AliExpress, so prices here are mostly unverified..
Do I need a 3D printer for the OpenBot (DIY body)?
Yes. Regular body needs a 240x150 mm bed; slim body fits 220x220 mm at 45 degrees; glueable body fits 150x140 mm. Also print the two phone mount parts. Without a printer, the BOM lists cheap car chassis kits instead.
Is there a kit for the OpenBot (DIY body)?
Yes: Amazon (official BOM, alternative), Amazon (official BOM, no 3D printer). Check what each kit leaves out before ordering.
Buying guides for this build
Similar builds
NVIDIA JetBot (Orin Nano version)
Small two-wheel camera robot on a Jetson board, built to teach collision avoidance and road following with neural nets.
OpenBot (DIY body) vs NVIDIA JetBot (Orin Nano version)
Last checked 2026-10-25. Sources: github.com · github.com · github.com · github.com · store.arduino.cc · www.adafruit.com · www.adafruit.com