timer_reset wasn't fully implemented for all timers on all series, and was simply a wrapper of the RST bits in the RCC registers anyway. First part of https://github.com/libopencm3/libopencm3/issues/709
README
This is a simple example that sends the value read out from the temperature sensor ADC channel of the STM32 to the USART2.
This example uses a timer trigger to automatically sample the adc channel.
The terminal settings for the receiving device/PC are 115200 8n1.