electronics

january 2019

contact: it is as if @ protonmail dot com

roadster electronics

these pages lag behind reality and are erratically updated.

the hardware here was designed for the roadster project but is quite generalized. it's aimed at closed loop motor/motion control with analog feedback and various digital and analog controls and sensors. automotive environment meaning norminal 12 volts negative ground, high current (1 to 25 amp) nasty inductive loads (so things like LEDs are trivial). sensors and inputs are low-impedance. power control, management, and filtration designed in. PWM control of everything heavy. internal thermal management. flexible/configurable analog/logic input networks.

there are two boards, POWER and ANALOG. these are Arduino Mega 2560 format stackable boards, use either or both (roadster computers all use both). here is the documentation for the boards, schematics and gerber files. if the Eagle files are interesting let me know i'll put them up. the BOMs are not very good however.

both ANALOG and POWER boards work with Arduino Mega 2560 and Arduino DUE, and should work as-is with the soon-to-exist AdaFruit "Metro Grand Central" board with a fully-broken-out 120 MHz SAMD51 processor. woo woo!

(there were a number of iterations of the now-obsolete electronics in the roadster, most of it hand wired.)

40mm fan, POWER, ANALOG boards on Arduino Mega 2560

analog schematic analog board Gerbers
power schematic power board Gerbers

here is the code that drives this hardware. the Cooling computer has it's own page.

the panel computer looks more like what most people think a computer is. it contains the same ANALOG and POWER boards but has a large LCD and some glue logic for it and the required manual controls.

ANALOG

the analog board has analog and logical inputs, and four modest power outputs.

ANALOG board, revised mar18

POWER

the power board contains eight high-current automotive high-side drivers, board/system power management, output load current sense, load power source voltmeter. the VN5E010 chips provide short-circuit protection, load dump and reverse battery protection, and have internal thermal management and feedback, all supported by the board and code.

POWER board, revised mar18
solder sides

ASSEMBLY

the boards stack onto each other, and an Arduino Mega 2560, and fit into a semi-open plastic box which is mounted to the inner firewall. the boards are plastic spray coated to protect against condensation.

analog and power boards stack on a Mega 2560
stacked with thermal
as installed. the two small black cables are Uplink and Downlink.