Ted Huntington
Open-Source Robot Building Kit and Development Environment
The main products in this robot building kit are:
1) Ethernet Modules (PCBs)
a) EthMotors - a Microchip PIC32 controls up to 12 motors (up to 2.8A each, using 12 Texas Instruments' DRV8800 motor drivers) over 100Mbit ethernet all on a single 100x72mm PCB. Uses 3.3V power supply, and an 8-36V motor power input. One to twelve motors can be connected individually into spring terminals. BOM cost: $64
b) EthAccel - a microchip PIC32 can read from up to 3 Accelerometers+Gyroscopes (currently only InvenSense MPU-6050), and 15 touch sensors (ADC), at up to 100 samples/s. Uses 3.3V power supply. The two wires from a touch sensor are connected into top and bottom holes in the SMD spring terminals and read on the PIC32 ADC pins. Note that in this image 2 8-bit SMD spring terminals are not populated (and that the GPS code is currently not functional). BOM cost: $28
c) Accelerometer PCBs: This humble PCB houses an accelerometer+gyroscope IC, is fastened onto the robot part with screws, and connects to the EthAccel PCB using an RJ12 cable. BOM cost: $3
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d) EthSwitch
1) 8-ports: A 100X60mm PCB that uses one (very low cost) Realtek RTL8309 IC to provide up to 8 10/100Mbit connections. Uses 3.3V power supply. BOM cost: $20
2) 16-ports: A 100X100mm PCB that uses two (very low cost) Realtek RTL8309 ICs to provide up to 16 10/100Mbit connections. Uses 3.3V power supply. BOM cost: $37
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2) Mechanical Products
a) Linear Actuator (1) - Rack and pinion design: low cost gear motor connects (using a clamping coupling) to a pinion which moves a connected rack. This design provides a startling amount of holding strength, and acts somewhat like a low cost, light-weight stepper motor because the gear teeth are somewhat far apart.
I think, personally, that this particular product in the Robot Kit is potentially one of the most valuable, perhaps after the 3 PCBs, because I searched and searched for linear actuators, but most of those being sold are metal, heavy, and expensive. For a robot that is going to use 9 linear actuators just for the lower body, that would be very heavy and expensive. This rack and pinion design plastic linear actuator has more than enough strength, is much lighter than a metal actuator, and is about 100x cheaper.
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b) Linear Actuator (2) - Linear screw design: low cost gear motors connects (using a clamping coupling) to a lead screw/threaded rod which pushes a plastic rod that has an embedded nut. Much slower, but much stronger than the rack and pinion design. This linear actuator could be used on a robot to push a large weight, but is too slow for most robot applications. Nonetheless there is plenty of room for adapting the basic design for a wide variety of applications.
c) Touch Sensor - Conductive foam surrounded by metal tape on each side and enclosed in plastidip. Two wires coming from the sensor can be connected to the ADC ports on the EthAccel to log (up to 100 times/second) the variable resistance of the sensor. Large or small size.
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3) Test Devices
a) Three-wheel robot - 20mm (w) x 15mm (h) x 20mm (d) robot with 12v battery (note battery: will be smaller lithium ion battery with an optional charger), banana pro, 2 switch-mode voltage regulators, and a small banana pro power adapter PCB (converts regulator 5v to USB and SATA connectors). Robot has two motors connected to clamping couplings that turn plastic wheels, and can be controlled wirelessly (untethered) using a Bluetooth keyboard and/or remote desktop into the Banana Pro.
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b) Robot motor testing weight lifting arm - Plastic two-part arm that can be used to test the strength of a motor.
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Coolest Parts of this Project:
1) All open...
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Pavel Surynek
Gaultier Lecaillon
Will Donaldson