Add ADC example for STM32F411 (#952)

* Add ADC example for STM32F411

* Update dependencies

* Update RTIC version

* example: f411-adc: prefer text over picture

* example: f411-adc: nit: typo

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Co-authored-by: Milton Eduardo Sosa <milton@Miltons-MacBook-Pro.local>
Co-authored-by: Henrik Tjäder <henrik@tjaders.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/examples/stm32f411_adc/README.md b/examples/stm32f411_adc/README.md
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+# STM32F411CEU6 ADC example 
+Working example to work with the internal ADC of the STM32F411CEU6 present on a Blackpill board.  
+
+The `#init` task configures the ADC module for single-shot conversion and `PA1` as analog pin.  
+
+Afterwards, the analog pin stored in a Potentiometer struct is set as a **local** resource to the hardware task associated to `EXTI0`.  
+
+The `Adc<ADC1>` instance on the other hand, is set as a **shared** resource. The reason behind this approach is to allow other tasks make use of the only ADC module present on this microcontroller.  
+
+
+
+## How-to
+
+### Build
+Run `cargo build --release` to compile the code. If you run it for the first time, it will take some time to download and compile dependencies.
+
+### Run
+Install `probe-rs` and configure it using the [debugging extension for VScode](https://probe.rs/docs/tools/debugger/).  
+The output should look like this:
+
+```
+INFO Current delay value 1900
+INFO Current ADC value 665
+
+INFO Current delay value 1800
+INFO Current ADC value 1138
+
+INFO Current delay value 1700
+INFO Current ADC value 1136
+
+INFO Current delay value 1600
+INFO Current ADC value 811
+
+INFO Current delay value 1500
+INFO Current ADC value 1752
+```