This open source controller for the peripherals of an electric car. Looks like it could save an EV Builder allot of time and work. Check out the VUE32...

Don

SourceForge.net: VUE32 - openecosys

VUE32

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Overview

Within the framework of a Capstone Project, twelve students in mechanical engineering and fifteen students in electrical engineering chose to design and build an urban electric vehicle with active torque vectoring. As there is actually no such thing as a freely available car control architecture which would allow us to test and implements our ideas on an existing vehicle, we designed one. The approach taken favours a highly modular hardware architecture, built around multiple VUE32 boards and a Panda Board embedded computer. This page covers the VUE32 module.

This project is released under an Open Hardware licence.

For additional details, please refer to Projet VUE's official web page: [1]

The Car

Modified Smart ForTwo
Active torque vectoring
2 independent Enstroj EMRAX motors (info: [2])
- Water cooled
- 2x 50kW (roughly 140hp!)
Piktronik SAC41 Drives (info: [3])
7x VUE32 on a CAN network
1x PandaBoard embedded computer
2x LCD displays

For additional details and pictures of the car, please refer to Projet VUE's official web page: [4]

Functionalities and details

PIC32MX795F512H Microcontroller
- 80MHz, 1.56 DMIPS/MHz, 32-bit MIPS M4K® Core
- 512K Flash, 128K RAM
- USB 2.0, 2 x CAN2.0b
8x Digital I/Os, 0-3.3V (protected)
4x External 10 bits ADC 0-3.3V (protected, filtered)
2x Speed sensor inputs, compatible with standard car's magnetic speed sensors
4x 12V 10A power outputs
2x 2A motor driver outputs
1x I²C
Onboard sensors: temperature and battery voltage
Compact design
- 4-layers 95 x 54.25mm PCB
- Custom enclosure
Open source hardware, Altium files available
Open source software, based on the NetV stack

Detailed hardware description

Schematic

Complete PDF Schematic: [[5]]

Page by page description:

p. 1/10: Top sheet
p. 2/10: 4 channel analog inputs. Details: VUE32_4CH_ANALOG
p. 3/10: CAN
p. 4/10: 2A DC Motor driver
p. 5/10: PIC32
p. 6/10: Power output. Details: VUE32_PWR_OUT
p. 7/10: Digital I/Os
p. 8/10: Speed sensors. Details: VUE32_SPEED
p. 9/10: Supplies. Details: VUE32_SUPPLIES
p. 10/10: USB-Serial

General comments:

Additional information pages are supplied when the comments on the schematic were not judged complete enough. Feel free to request more information.
Partial assembly is used to keep the cost at a minimum
There is only 1 USB connector, even if there is on-board USB and a USB-Serial bridge. The later one was added only as a security (in case we couldn't use the USB stack due to timing considerations). As the onboard USB works flawlessly, the USB-Serial peripheral is not used.

PCB

2D PCB Top view	3D PCB Top view
Top Layer: signals	Inner Layer 1: GND plane
Inner Layer 2: power planes	Bottom Layer: signals

General comments:

259 components, 793 pads, 536 via/holes, 94 x 54.25mm
We used Labo Circuit's Standard specs: [6]
The assembly was done on a pick and place, reflow soldering
97.7% of the components are on the top layer to reduce the assembly cost (single stencil). The only components on the bottom side are optional jumper resistors (in an easy to solder 0603 package).

Simulations

A couple simulations were made in LTSpice. The files are in the main archive. Here's an example, the power output:

Enclosure

Custom enclosure, designed especially for the VUE32 board:

3D animation of the first design: [7]

This design offers the equivalent of an IP31B protection:

IP31B: Solid particle protection: >2.5 mm (Tools, thick wires, etc.)
IP31B: Liquid ingress protection: Dripping water (Dripping water (vertically falling drops) shall have no harmful effect.)
IP31B: Protected against access to hazardous parts with fingers

For all the details: [8]

This is far from being perfect. It was designed that way to keep costs down and to simplify connector selection. In our car, they are placed in protected areas. The next step would be to pick new connectors and design a sealed enclosure to reach at least an IP64D (or even IP66D) rating. That way, we could place these boards everywhere in the car, not just in protected areas.

Peripherals

Here is a brief list of the automotive peripherals that we use with the VUE32:

Sensors and user input:

CAN steering wheel position sensor
Yaw and lateral acceleration sensor (analog)
Lights lever
Wipers lever
Key, D/P/R lever
Battery current sensor
Magnetic speed sensors
Doorlock switches, windows switches
Pedal position sensors (analog)

Output peripherals:

All kinds of lights: low beams, high beams, flashers, ...
Wipers: arms and washer pump
Power windows
Door locks
Pumps
Blowers
Audio amplifier enable
Relays

Excellent source of information: Evilution [9]

Software

We are actively developing our software at this time. As soon as we have a Release Candidate the sources will be posted here.

Does it work?

Of course! We waited a long time before releasing the details to be sure that the boards were thoroughly tested. While v0.1 (our initial design) had some issues, v1.0 is almost perfect.

Here is an extract of our QA sheet, as of October 10th 2012:

An example of what we went through to qualify our power outputs. Notice the size of the power resistor compared to the size of the board!

**Power output qualification**

Known issues:

Wrong resistor value, analog inputs. Refer to VUE32_4CH_ANALOG.
Can't do hot power swapping. Refer to VUE32_SUPPLIES.

Pictures

**Freshly assembled VUE32 v1.0**

**Fully assembled VUE32 v1.0 with enclosure**

Design files and license

Hardware files

This project is licensed as Open Source Hardware. Here is an extract of the definition, according to Sparkfun:

If a device or project has this icon, it means the plans must:

Contain editable source files
Allow for modification
No discrimination against groups [...] or technology [...]
You are allowed to sell your version. No -NC limitations.
May require attribution

All the details are available on their website: [10]

We are not selling this board. This project was purely educational, not for profit. By releasing this design we hope we will help the development of electric cars of all kinds.

Let us know if you use the files and give us credit. That's the least we can ask. Contact: j f d u v a l @at@ a q r a .dot. c a.

All the design files are available here: [11]

Free Altium Viewer: [12]