AN2658

ADC conversion triggered by TIM1 timer

Doc ID 14152 Rev 2

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7

ADC conversion triggered by TIM1 timer

7.1

Overview

This section describes how to start and ADC conversion triggered by the TIM1 trigger

output.

There are several ways of starting ADC conversions in the STM8 including any event that

can be generated by the multipurpose timer (TIM1). This gives the you a large choice when

implementing your application.

7.2

Hardware description

Figure 14 shows a typical connection between the STM8 AIN9 pin and a potentiometer. This

allows you to test the ADC by changing the input voltage to be converted. The conversion

result is displayed on four LEDs. This example hardware is implemented in the STM8

evaluation board STM8/128-EVAL.

7.3

Firmware description

The STM8 firmware library includes the ADC driver that supports the ADC through a set of

functions.

ADC is configured in continuous conversion mode with interrupt enabled. The conversion is

triggered by the TIM1 TRGO event. In the interrupt routine, the range of the converted value

defines the number of LEDs to light up each time a conversion occurs.

This firmware is provided as ADC example 2 in the STM8 firmware library, available from the

STMicroelectronics microcontroller website.