AN4157

Peripheral firmware examples description

Doc ID 023629 Rev 1

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Peripheral firmware examples description

3.1

ADC example

3.1.1

Purpose

This example describes how to use the ADC1 to convert continuously the voltage applied to

a given analog input channel.

3.1.2

Description

In this example, detailed steps of ADC configuration are provided starting from GPIO

configuration to the analog channel configuration without forgetting the ADC calibration

procedure. The ADC1 Channel7(PC1) is used as directly connected to the external power

supply (ranges between 0 and 3.3V).

The converted voltage is stored in the ADC1ConvertedVoltage variable.

3.2

CRC 8-bit message example

3.2.1

Purpose

This example describes how to use the CRC peripheral in order to compute 8-bit CRC

checksum of a message.

3.2.2

Description

In this example:

●

The CRC peripheral is configured to use the 8-bit CRC polynomial x8 + x7 + x6 + x4 +

x2 + 1 with the initialization value set to 0.

●

The message is declared as an array and labeled "CRCBuffer". The expected CRC

value is already computed using an on line CRC tool. Once the CRC value is

computed, the computed CRC value is compared to the expected one.

●

In case of match the Blue led LD4 is turned on.

●

Otherwise the led LD3 is turned on.

3.3

DAC signal generation example

3.3.1

Purpose

This example describes how to use the DAC peripheral to generate several signals using

DMA controller.

3.3.2

Description

In this example, when the user presses the push-button, DMA transfers two selected

waveforms to the DAC.