This article explores design techniques and challenges for implementing an electronic bike (E-Bike) built using a microcontroller or Programmable System on Chip (PSoC). Current E-Bike systems use a microcontroller with external signal conditioning and comparator circuitry to drive the three-phase motor; external ADC and external amplifiers for different sensor inputs; relay driver circuitry for brake light, headlight, and directional lights; LED/ LCD displays; and temperature measurement.
Programmable SOC devices can be used in E-Bike applications as a single-board system for motor control, analog measurement, and direct drive LCD display. Programmable SOCs can also support capacitive sensing technology to replace mechanical buttons on the keypad. In addition, SOC devices use internal PWM, MUX, and comparators for driving and controlling the three-phase motor, internal ADC and PGA for sensor inputs battery monitoring, and temperature sensing using a temperature sensing device like a thermistor or RTD. The device can also directly drive the relays for the brake light, headlight, and directional lights, as well as direct drives the LCD display of temperature, battery status, speed, distance travelled, and any error/warning messages.
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.