[Review of Arteli Development Board AT32F421] + Have a good understanding of the power supply voltage

西点钟灵毓秀

[Review of Arteli Development Board AT32F421] + Have a good understanding of the power supply voltage [Copy link]

 

How to measure the power supply voltage without a multimeter? Of course there is a way...

Today we will take a look at the AD function of AT32F421.

AT32F421 has 15 12-bit ADC acquisition ports, which is more than enough for general projects.

It can be used to measure battery voltage and collect ambient temperature. . . .

Let's take a look at the AD input location on the development board

There are 6 channels in the blue box. We choose one of them (PA1) for testing.

Part of the ADC initialization program:

A single conversion is sufficient to measure the battery voltage.

Let's do a simple test, loop calling AD sampling in the main function, and print the value through the serial port.

Let's take a look at the board's power supply voltage of 3.3v, which is magnified 1000 times here, in MV.

Then let's measure the voltage of a 18650 lithium battery:

The results of the multimeter measurement are as follows:

The voltage is 2229MV. Let's look at the test results of AT32F421:

It is basically consistent with the measurement results.

For specific applications, please refer to the attachment.

In general, the 12-bit ADC of AT32F421 is quite accurate. You can use it with confidence in your project.

littleshrimp

Good, there is also an internal reference voltage

w494143467

Haha, measuring low voltage is not bad!

freebsder

Thanks for sharing! Looking forward to the follow-up!

Gen_X

Question: Your measurement result is 3298mV

The voltage measured by the meter is 2.229V?!

The difference between the two is not negligible, how can you think they are similar?

Also, is your PA1 directly connected to the battery? The voltage of this 18650 battery is between 3.2-4.2V. Have you done hardware voltage division?

This conversion process was not seen in the calculation.

If it is really 2.229, then is the voltage read by F421AD the voltage of the separate power supply?

西点钟灵毓秀

Gen_X posted on 2021-5-24 13:20 Question: Your measurement result is 3298mV, and the meter measured 2.229V? ! The difference between the two cannot be ignored, how can you think they are almost the same...

You definitely didn't read the content carefully.

Look back again...

3298mV That is the onboard voltage: 3.3V voltage

The one below is the battery voltage: 2.229V,

The measurement results are 2228MV ~ 2229MV. . . . .

Gen_X

Xidian Zhong Lingyuxiu published on 2021-5-24 14:20 You must not have read the content carefully. Look back... 3298mV That is the onboard voltage: 3.3V voltage...

Thanks for the tip, I saw it.