| icon |
|---|
simple/arduino |
The RA6M5 Thing Plus includes several breakout pins with access to the 12-bit ADC channels of the RA6M5. These feature is primarily used to record analog data from potentiometers and various sensors. For this example, users are free to utilize any hardware they have to connect the ADC from the A0 GPIO pins to an analog signal. We recommend selecting a device with a product manual that provides electrical diagrams and example code; below, are a few examples:
??? note "Optional Hardware"
- <a href="https://www.sparkfun.com/products/12758">
<figure markdown>
</figure>
---
**SparkFun Electret Microphone Breakout**<br>
BOB-12758</a>
- <a href="https://www.sparkfun.com/products/9088">
<figure markdown>
</figure>
---
**Mini Photocell**<br>
SEN-09088</a>
- <a href="https://www.sparkfun.com/products/9806">
<figure markdown>
</figure>
---
**Trimpot 10K Ohm with Knob**<br>
COM-09806</a>
- <a href="https://www.sparkfun.com/products/9194">
<figure markdown>
</figure>
---
**Jumper Wires Premium 6" Mixed Pack of 100**<br>
PRT-09194</a>
- <a href="https://www.sparkfun.com/products/501">
<figure markdown>
</figure>
---
**IC Hook Test Leads**<br>
CAB-00501</a>
</div>
Below, are some basic example sketches for capturing analog data from generic devices such as a potentiometer or photocell.
=== "AnalogReadSerial.ino"
Users can find this sketch in the File > Examples > 01.basics > AnalogReadSerial drop-down menu.
??? code "`AnalogReadSerial.ino`"
--8<-- "https://raw.githubusercontent.com/arduino/docs-content/main/content/built-in-examples/01.basics/AnalogReadSerial/AnalogReadSerial.md:57:57"
=== "ReadAnalogVoltage.ino"
Users can find this sketch in the File > Examples > 01.basics > ReadAnalogVoltage drop-down menu.
??? code "`ReadAnalogVoltage.ino`"
--8<-- "https://raw.githubusercontent.com/arduino/docs-content/main/content/built-in-examples/01.basics/ReadAnalogVoltage/ReadAnalogVoltage.md:57:57"
To implement the #!cpp AnalogWave library from the Renesas Arduino core, users will need to link the library at the beginning of their sketch.
#include "analogWave.h" // Include the library for analog waveform generationOnce linked, users will need to create an instance of the #!cpp analogWave class and declare a DAC pin for the output.
analogWave wave(pin); // Create an instance of the analogWave class, using a DAC pin!!! tip
In the Renesas-Arduino core, DAC and DAC1 are predefined variables for their corresponding GPIO pins on the RA6M5 Thing Plus.
!!! code
```c++
analogWave waveA0(DAC); // Create an instance of the analogWave class, using the DAC pin (A0)
analogWave waveA1(DAC1); // Create an instance of the analogWave class, using the DAC1 pin (A1)
```
Below, are a few of the key methods available for the analogWave class:
??? code "Methods in analogWave.h"
```cpp
--8<-- "https://raw.githubusercontent.com/arduino/ArduinoCore-renesas/main/libraries/AnalogWave/analogWave.h:42:54"
--8<-- "https://raw.githubusercontent.com/arduino/ArduinoCore-renesas/main/libraries/AnalogWave/analogWave.h:62:64"
```
*For more information, please refer to the [`analogWave.cpp`](https://github.com/arduino/ArduinoCore-renesas/blob/main/libraries/AnalogWave/analogWave.cpp) file in the `AnalogWave` library.*
When generating an output signal from the DAC of the RA6M5 Thing Plus, users will need to define the waveform's type and frequency:
int freq = 20; // waveform frequency in Hzwave.sine(freq); // Generates a sine wave with a 20Hz frequencyOscilloscopes are the perfect tool to capture the waveform of a signal output. While useful, not all users will have access to this type of test equipment. For this example, user will need connect the probe from an oscilloscope to the DAC (A0) and GND GPIO pins.
!!! code "Sine Wave" ```cpp #include "analogWave.h" // Include the library for analog waveform generation
analogWave wave(DAC); // Create an instance of the analogWave class, using the DAC pin
int freq = 60; // in hertz, change accordingly
void setup() {
wave.sine(freq); // Generate a sine wave with the initial frequency
}
void loop() {}
```
??? tip "Oscilloscope Adjustments" The DAC of the RA6M5, generates a waveform with a positive voltage. Therefore, user may need to adjust the vertical position of the probe's input channel.
Users may also find it helpful, to set the trigger on a discretized voltage step.
Another method to record the signal generated by the DAC, is with a jumper (wire) and looping a output signal from the DAC1 GPIO pin back into the A2 GPIO pin. While an oscilloscope is very useful, this is a more practical and cost-effective alternative for users. With this example, users are free to utilize any method or hardware they have to connect the DAC1 and A2 GPIO pins together. However, we recommend some IC hooks for a temporary connection.
??? note "Optional Hardware"
- <a href="https://www.sparkfun.com/products/501">
<figure markdown>
</figure>
---
**IC Hook Test Leads**<br>
CAB-00501</a>
- <a href="https://www.sparkfun.com/products/9741">
<figure markdown>
</figure>
---
**IC Hook with Pigtail**<br>
CAB-09741</a>
- <a href="https://www.sparkfun.com/products/9194">
<figure markdown>
</figure>
---
**Jumper Wires Premium 6" Mixed Pack of 100**<br>
PRT-09194</a>
- <a href="https://www.sparkfun.com/products/116">
<figure markdown>
</figure>
---
**Break Away Headers - Straight**<br>
PRT-00116</a>
- <a href="https://www.sparkfun.com/products/9044">
<figure markdown>
</figure>
---
**Jumper - 2 Pin**<br>
PRT-09044</a>
</div>
After users have jumpered the GPIO pins and uploaded the example code, they will need to open the Serial Plotter in the Arduino IDE. Once opened, the tool will begin to plot the values that are received from the serial port. It should be noted that the Serial Plotter tool is unavailable in the legacy Arduino IDE v1.x.x; and some users may need to upgrade to the new Arduino IDE v2.x.x to access this tool. Additionally, the speed and buffer of the Serial Plotter tool are limiting factors in its performance. Therefore, careful consideration should be made when adjusting the waveform frequency and the delay intervals between readings.
!!! code "Sine Wave" ```cpp #include "analogWave.h" // Include the library for analog waveform generation
analogWave wave(DAC1); // Create an instance of the analogWave class, using the DAC pin
int freq = 1; // in hertz, change accordingly
void setup() {
Serial.begin(115200); // Initialize serial communication at a baud rate of 115200
wave.sine(freq); // Generate a sine wave with the initial frequency
}
void loop() {
// Print the updated frequency to the serial monitor
Serial.println(String(analogRead(A2)));
delay(20); // Delay for 20ms before repeating
}
```
!!! Serial "Serial Plot"
{ width=400 }
Serial Plot of a sine wave output from the DAC GPIO, which was read by the A2 GPIO.
??? abstract "Other Waveforms" Users can modify this example to generate other types of waveforms, as shown in the examples below.
<div class="grid" markdown>
<div markdown>
<figure markdown>
[{ width=400 }](./assets/img/hookup_guide/example-analog_square.gif "Click to enlarge")
<figcaption markdown>**Serial Plot** of a square wave generated by the `DAC` GPIO, which was recorded by the `A2` GPIO.</figcaption>
</figure>
!!! code "Square Wave"
Users can modify the type of waveform output by the DAC. The modification below will generate a square waveform:
{--wave.sine(freq);--}
{++wave.square(freq);++}
</div>
<div markdown>
<figure markdown>
[{ width=400 }](./assets/img/hookup_guide/example-analog_saw.gif "Click to enlarge")
<figcaption markdown>**Serial Plot** of a sawtooth wave generated by the `DAC` GPIO, which was recorded by the `A2` GPIO.</figcaption>
</figure>
!!! code "Sawtooth Wave"
Users can modify the type of waveform output by the DAC. The modification below will generate a sawtooth waveform:
{--wave.sine(freq);--}
{++wave.saw(freq);++}
</div>
</div>