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| -rw-r--r-- | README.md | 20 |
1 files changed, 11 insertions, 9 deletions
@@ -9,7 +9,7 @@ Features: * ARM Cortex M0+ microcontroller * 32KHz crystal for real-time clock with alarm function * Ten digit segment LCD, plus five indicator segments -* Three interrupt capable buttons (one can wake from backup mode) +* Three interrupt capable buttons * Red / green PWM’able LED backlight * Optional piezo buzzer (requires some light soldering) * On-board USB Micro B connector @@ -18,16 +18,18 @@ Features:  -You may have noticed that there are no sensors on this board. That is by design: rather than pick sensors for you, the goal is to add a tiny flexible PCB with the sensors YOU want, and interface them over the nine-pin connector. In addition to providing ~3V power and ground, the connector provides the following options for connectivity: +You may have noticed that there are no sensors on this board. That is by design: rather than pick sensors for you, the goal is to add a tiny flexible PCB with the sensors YOU want, and interface them over the nine-pin connector. The connector provides the following options for power and connectivity: -* An I2C interface with built-in pull-ups +* 3V power (nominal voltage from a CR2016 coin cell, can drop to ~2.7V) +* An I²C interface with built-in pull-up resistors * Five general purpose IO pins, which can be configured as: - * Three analog inputs and two digital IO - * An SPI device + one analog / GPIO pin - * One UART + 3 GPIO - * Five digital IO pins - * Four PWM pins on two independent TC channels - * Five interrupt pins (two can wake from backup mode) + * Five analog inputs + * Five interrupt-capable digital inputs, with internal pull-up or pull-down resistors + * Five digital outputs + * SPI controller (with one spare analog / GPIO pin leftover) + * One UART TX/RX pair (with three GPIO leftover) + * Up to four PWM pins on two independent TC instances + * Two external wake inputs that can wake from the ultra-low-power BACKUP mode  |