Learn Arduino?

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I have a couple of PCBs coming...

This is a 8 way I2c High Side Driver. It is for the Codan 8727 but also for general use when the screw terminals are fitted.

And a PCB for the 4x7Seg LED display we played with earlier. This should run brighter as there are transistors for switching.
There is plenty of proto area too.

 

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The boards are still in Sydney as far as I can see
They have been there for over a week.......

 

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I'm still hopeful that the PCBs will arrive in time.
If I've read the SevSeg libraries correctly, the setup for having PNP drivers on the Anodes will be as follows.
It was not really explained well at all.

void setup() {
  byte numDigits = 4;
  // pins in order to suit the TSB5882 display
             // digits 1, 2, 3, 4 (staring from the left)
  byte digitPins[] = {11,10, 8, 4};
             // segment  a, b, c, d, e, f, g, dp 
  byte segmentPins[] = {13, 7, 9,12, 5, 6, 2, 3};
   
  bool resistorsOnSegments = true; // 'false' means resistors are on digit pins  
/*
    byte hardwareConfig = COMMON_CATHODE;     // = 0 (digitOnVal=LOW,  segmentOnVal = HIGH)
    byte hardwareConfig = COMMON_ANODE;       // = 1 (digitOnVal=HIGH, segmentOnVal = LOW)
    byte hardwareConfig = N_TRANSISTORS;      // = 2 (digitOnVal=HIGH, segmentOnVal = HIGH)
    byte hardwareConfig = P_TRANSISTORS;      // = 3 (digitOnVal=LOW,  segmentOnVal = LOW)
    byte hardwareConfig = NP_COMMON_ANODE;    // = 0 (digitOnVal=LOW,  segmentOnVal = HIGH)
    byte hardwareConfig = NP_COMMON_CATHODE;  // = 1 (digitOnVal=HIGH, segmentOnVal = LOW)
*/
  byte hardwareConfig = P_TRANSISTORS; // PNP transistors on common Anodes. Arduino ports on Cathodes.
  
  bool updateWithDelays = false; // Default 'false' is Recommended
  bool leadingZeros = false; // Use 'true' if you'd like to keep the leading zeros
  bool disableDecPoint = false; // Use 'true' if your decimal point doesn't exist or isn't connected
  
  sevseg.begin(hardwareConfig, numDigits, digitPins, segmentPins, resistorsOnSegments,
  updateWithDelays, leadingZeros, disableDecPoint);
  sevseg.setBrightness(100);
}

 

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This workk to test the 8 way high side driver board, as long as the address is set correctly. For the PCF8574A with link A0 installed, the address is 0x3E.

 

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They have arrived

 

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The LED display works

The PCB has 150R resistors marked but as I did not have any, 220R have been used and the LEDs are bright enough and as a bonus, the didgit current is below the max for the BC557 transistors. Don't use 150R.

 

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The other board, the Codan 8727 Band Select, can be used for a general purpose high side 8 way driver.

Address selection...

 

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In hind sight, I realize adding an I2C connector to the 7 seg board would have been a good idea.
Here is one grown on...

and running both boards together.

 

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If you don't want to write the code yourself, how about getting an AI to help?
It looks like it would be fun to try.

http://www.sadarc.org/xenforo/upload/index.php?threads/let-an-ai-write-code-for-you.366/

 

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Here is the data sheet for the MIC2981 chip used in the high side driver board.
It has 8 drivers, each of max 50V at 500mA. The total package current is 3Amps so it is a pretty handy board.

 

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NOTE> If you use the PCF8574 chip, the address range is 0x20 to 0x27
If you use the PCF8574A chip, the address range is 0x38 to 0x3F

 

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For this coming class, I thought it may be interesting to look at Ultrasonic Distance Sensing.
There are a number of types readily available, the HY-SRF04 with a TX and an RX unit as below. These cost less than $5 in Australia.
There is a SRF05 that looks similar and costs a bit more. I don't have any of those to compare the performance.

These DYP-ME007Y single unit sensors seem to work a lot better but are close to $20 from China.

JSN-SR04T Integrated Ultrasonic Module Distance Measuring Transducer N7K7 below features a fully sealed remote sensor. I have some of these but the magic "somewhere" comes into play! These are a bit under $20 here from Oz.

There is a pretty good explanation of how these work at...
https://arduinogetstarted.com/tutorials/arduino-ultrasonic-sensor and they also publish some example code that we will try out at the lesson.
I'll bring printouts along for you to type in, or you could just download the files from the attached zip.

 

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I've just been watching a very good Youtube video to do with these sensors.

This is from the Drone Bot Workshop channel.

https://www.youtube.com/@Dronebotworkshop

His comment about the speed of sound through different mediums was quite good. See if you spot it. I've never thought of Pink Floyd being used to demonstrate a physics property!

 

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Just for interest, here is a video for the waterproof ultrasonic sensors mentioned earlier.

This sensor has some built in smarts and can operate in 5 modes...

Watch the video for details.

 

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This gent, Erik Meike, has modified the HC-SR04 sensor...

He taps into the analog out of the sensor...

and displays the signal on an OLED display....

Here you can see the echos of both his hand and the cardboard box.

I have not tried it as yet but here it is if anyone wants to have a play.
First, I have to install the ADC libs!
Also, this runs on a Teensy board, not a "standard" Nano, so that board will need to be installed too.

Using Teensy with Arduino IDE - Tutorial Australia

If you’ve come looking for how to get your Teensy board up and running using the Arduino IDE, then you’ve come to the right place. Whilst you can use the standard Teensy loader application to flash compiled code directly to your Teensy, most people prefer to write and upload their code straight...

core-electronics.com.au

I have a Teensy somewhere so I may have a go at this.

 

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To make connecting things to your Arduino Uno a little easier, a Sensor Shield, like this one is a good idea.

each pin is extended to headers with a gnd and +5V pin.
There are also dedicated connectors for a few, like the analog and the I2C/serial (select able with jumpers).

This is a circuit for the board, or at least, something like the one you may get.
A similar shield is available for the Arduino Nanos.
This is but one version...

The port pin headers are arranged in the order Gnd-Volts-Signal that suits the connectors on the ends of servo leads.

Brown = Gnd.
Red = +5V.
Orange = Signal.

 

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I've started to play with an RTC board.

It has a CR2032 cell socket on the back. Also, there is a place for a DS18S30 temperature sensor (of which I have some in stock). Also, an EEPROM.

It is mounted with an extra I2C socket and a pin that makes the square wave out available.

#define Version "RTC_Temp_Pot_demo"

#include <RTClib.h>
RTC_DS1307 rtc;

#include <OneWire.h>
#include <DallasTemperature.h>
// Data wire is conntec to the Arduino digital pin 4
#define ONE_WIRE_BUS 4

/* info found by running DS18x20_Temperature from Examples/OneWire
   This will vary between chips.
ROM = 28 86 F1 B6 4 0 0 2B    
  Chip = DS18B20
  Data = 1 87 1 4B 46 7F FF 9 10 48  CRC=48
  Temperature = 24.44 Celsius, 75.99 Fahrenheit
No more addresses.
*/
// Setup a oneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);

// Pass our oneWire reference to Dallas Temperature sensor
DallasTemperature sensors(&oneWire);

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
int PotReading      =  0;

// A4 = SDA
// A5 = SCL
#define Pot           A7

// One Wire Bus        4

void setup() {
  // put your setup code here, to run once:
  // automatically sets the RTC to the date & time on PC this sketch was compiled
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));

  lcd.init();                         // initialize the lcd
  lcd.backlight();
  lcd.print(Version);
  delay(1000);
  lcd.clear();
  lcd.setCursor(0,0);
  PotReading=analogRead(Pot);
  lcd.print("Pot=            ");
  lcd.print(PotReading);
  sensors.begin();        // start the Dals one wire

}

void loop() {
  // put your main code here, to run repeatedly:
  DateTime now = rtc.now();
  lcd.setCursor(4,1);         // then position the cursor
  lcd.print(now.hour(), DEC);
  lcd.print(':');
  lcd.print(now.minute(), DEC);
  lcd.print(':');
  lcd.print(now.second(), DEC);
   
    PotReading=analogRead(Pot);   // read the pot
      lcd.setCursor(4,0);         // then position the cursor
      lcd.print("     ");         // erase old reading
      lcd.setCursor(4,0);         // then position the cursor again
      lcd.print(PotReading);      // display new reading

// Call sensors.requestTemperatures() to issue a global temperature and Requests to all devices on the bus
      sensors.requestTemperatures();
      lcd.setCursor(8,0);         // then position the cursor
      lcd.print(" C=      ");         // erase old reading
      lcd.setCursor(11,0);         // then position the cursor again
      lcd.print(sensors.getTempCByIndex(0));      // display new reading

}

Things to add are the ability to set the time, maybe produce an alarm

 

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Some time ago, I watched a Youtube (by Ralph Bacon) video that had a neat hint on how to save space in your code after debugging is complete. So, here is a demo implementation of his idea.

Here is the code I've written following his video ideas.

#define Version "SerialDebugDemo"
// https://www.youtube.com/watch?v=--KxxMaiwSE

// if DEBUG = 0, there is no Serial used for the debugging.
#define DEBUG 1

#if DEBUG == 1
#define debug(x) Serial.print(x)
#define debugln(x) Serial.println(x)
#else debug(x)
#define debugln(x)
#endif

void setup() {
  Serial.begin(9600);
  debugln("Serial debugging enabled");
  Serial.println(Version);
}

void loop() {
  // put your main code here, to run repeatedly:

}

and the outputs..






This is a very handy trick that I hope I remember to use!


I used to do it this way, with an #if.... #endif for each debug message.

#define Version "SerialDebugDemoOldWay"
// https://www.youtube.com/watch?v=--KxxMaiwSE

// if DEBUG = 0, there is no Serial used for the debugging.
#define DEBUG 1

void setup() {
  Serial.begin(9600);
#if DEBUG == 1
  { Serial.println("Serial debugging enabled");
  }
#endif  
  Serial.println(Version);
}

void loop() {
  // put your main code here, to run repeatedly:

}

[!CODE]

That is ok for just one but gets messy for lots.

 

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As in the above example, #define is used to make the code easier to work with. Sometimes, the pins need to be redefined after the build, for example, wiring a rotary encoder up reversed. Something I do a lot!!!!
So, here is a way to do that. It was copied from the usdx code example.

#define VERSION "DefineMods01"

// example of redefining pins. In this example, swapping the pins of an encoder.
// uncomment the following line to swap the pins.

//#define SWAP_ROTARY    1   // Swap rotary direction


#define ROT_A   6         //PD6    (pin 12)
#define ROT_B   7         //PD7    (pin 13)


#ifdef SWAP_ROTARY        // was the encoder wired in reverse?
#undef ROT_A              // yes, undefine the pins
#undef ROT_B
#define ROT_A   7         //PD7    (pin 13) redefine the pins.
#define ROT_B   6         //PD6    (pin 12)
#endif

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}
[!CODE]

 

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The folk at randomnerdtutorials have just published a guide for sensors and modules.

ESP32: 26 Free Guides for Sensors and Modules | Random Nerd Tutorials

There is a wide variety of sensors, modules, and peripherals compatible with the ESP32 boards. This article is a compilation of 26 free guides for ESP32 sensors and modules.

randomnerdtutorials.com

They do havs a lot of good stuff, as I've mentioned before. Some of their guides that they sell are very good value, but they do have a mass of free stuff too.