NES 8bit Controller with Arduino

Perhaps this will help someone out there?

I purchased a 2-pack of rip off NES 8bit controllers on Amazon with an “extension” cord so that I had a ready made connector. Cut the extension cord off and wired it to an Arduino Mega (because that’s what was on the bench). I am using this for a game I am working on for the Makerspace… but through maybe you could use a snippet that worked. The first google code I tried to copy and paste didn’t work so hot.. so here is what I came up… I did find some inspiration here and there but this is a good launching point for your next project.

/*

NES Controller

*/

const int latch = 50;
const int clock = 48;
const int data  = 49;

#define latchlow digitalWrite(latch, LOW)
#define latchhigh digitalWrite(latch, HIGH)
#define clocklow digitalWrite(clock, LOW)
#define clockhigh digitalWrite(clock, HIGH)
#define dataread digitalRead(data)
#define wait delayMicroseconds(15)

unsigned long previousMillis = 0;
const int wait_interval = 20; 

const int A_BUTTON         = 0;
const int B_BUTTON         = 1;
const int SELECT_BUTTON    = 2;
const int START_BUTTON     = 3;
const int UP_BUTTON        = 4;
const int DOWN_BUTTON      = 5;
const int LEFT_BUTTON      = 6;
const int RIGHT_BUTTON     = 7;

byte output;

void setup() {
	Serial.begin(115200);
	pinMode(latch, OUTPUT);
  pinMode(clock, OUTPUT);
  pinMode(data, INPUT);
  Serial.println("NES TEST");

}

boolean isBitSet (byte myVar, byte bitNumber) {
  bool bitvalue;
  bitvalue = myVar & (1 << bitNumber);
  return bitvalue;
}  


void readNES() {
  latchlow;
  clocklow;
  latchhigh;
  wait;
  latchlow;
 
  for (int i = 0; i < 8; i++) {
     output += dataread * (1 << i);
     clockhigh;
     wait;
     clocklow;
     wait;
  }
}

void hexprint(byte b) {

  Serial.print("0x");
  if (b < 10) Serial.print("0");
  Serial.println(b, HEX);

}

void loop() {
  output = 0;
  readNES();
  if (!isBitSet(output, 0)) Serial.println("A Button");
  if (!isBitSet(output, 1)) Serial.println("B Button");
  if (!isBitSet(output, 2)) Serial.println("SELECT Button");
  if (!isBitSet(output, 3)) Serial.println("START Button");
  if (!isBitSet(output, 4)) Serial.println("UP Button");
  if (!isBitSet(output, 5)) Serial.println("DOWN Button");
  if (!isBitSet(output, 6)) Serial.println("LEFT Button");
  if (!isBitSet(output, 7)) Serial.println("RIGHT Button");
  //Serial.print("Read: "); hexprint(output);
}

Combining serial stream bytes/nibbles to make a number.

I thought I’d drop this here for someone who needed a copy-paste solution.

I am parsing a serial string output from a YDLIDAR X4 rotating lidar. I have to do this because the library sucks. a lot. I mean I’m not over my heels with the unit anyhow, first off who the hell outputs at 128,000 baud? I’ll post the code when it’s done enough for someone to build off of it.

I was getting an error in number of bytes in the packet as parsed from the serial string so I had to break out the function into really busy but obvious code to see where I was going wrong. The code has me concatenating two bytes and an upper nibble. Ignore the discrepancy in how I added my bytes backwards in my code vs. how the device actually stacks it’s data… because you know: WHO IN THEIR RIGHT MIND SHIFTS LSB ON THE LEFT?! (note the “length bytes as shown in 12 bits and the “response length” example below.)

Anyhow… feel free to show me how to do it better in the comments. Obviously this is built for you to look at it do it’s magic in a serial monitor.

//Arduino Friendly.
unsigned long rx_make_length(byte b1, byte b2, byte b3) {
  unsigned int msb_bits = 0; 
  unsigned long length_value = 0;
  
  //drop the lower nibble and prep for OR-ing.
  b3 = b3 >> 4;

  Serial.print("c w/ nibble removed and right shift: "); Serial.println(b3, HEX);

  msb_bits = b1;   
  msb_bits = msb_bits << 8;
  Serial.print("b1 shifted up 8 : "); Serial.println(msb_bits, HEX);
  msb_bits = msb_bits | b2;
  Serial.print("b1 concatenated w/ b2: "); Serial.println(msb_bits, HEX);
  length_value = msb_bits;
  length_value = length_value << 4; 
  Serial.print("b1 concatenated w/ b2 w/ shift: "); Serial.println(length_value, HEX);
  length_value = length_value | b3;
  Serial.print("b1 concatenated b2 and b3: "); Serial.println(length_value, HEX);

  return length_value;
}

//unsigned long my_value = rx_make_lenth(a, b, c);

iButtonLink / DS18B20 Arduino Datalogger

What a groaner.. who needs another datalogger? Well I do, so stuff it. I was inspired to check out these iButtonLink devices that allow you to daisy-chain connect a number of devices in a single circuit of sorts with RJ45 patch cables. I had seen these a couple years ago in some top-notch datacenters that terminated to a concentrator (4 strings) that were then pushed up to some IBM services app server.

A while back I published a Microsoft PIC microcontroller version of this … I decided to give it another whirl with the “easy button” … Arduino. Of course there were a couple libraries that I just had to collectively stuff into the same sketch and easy-peasy it was done in an hour or so.

This time I have my data stored to an SD card, which … I hastily put together.

If I was actually going to finish this I would add three things to this to finish it up.

  1. Use an RTC, figure an interface to enter the correct time. (maybe add an ethernet shield and get NTP?) … or just manual enter.
  2. I’d grab the interval time off the RTC and just have the loop do a non-blocking wait, then poll the RTC time or interrupt (whatever you favorite way to do this is..) that way I was collecting trend information on the “:00″s.
  3. I would add a method of checking for an SD card to be interested and allow it to start logging from card insert. I would also add time/date stamp to the file and finally, still SD card related I would check file size and stop logging when I got close to full.

So that is that. I’ve been creating a lot of fun lately but nothing mind-bending.. just going through every module I’ve ever bought doing the demo code … or going the other way around.. working on every Arduino demo/example in a class .. I’ve also built an FE boat, moved my workshop inside (update video coming kind of soon) and been working on PopBot 0.5 ..

The code:

/*
 * Chas Ihler
 * @chasxmd
 * https://iradan.com
 * 
 * License: Public Domain - it's mostly copy and paste and preferences anyways.
 * 
 * iButtonLink, grabs all sensors and logs them to card if present.
 * Recommendations: 
 * Add an RTC and a method of updating time. 
 * I'd also grab actual seconds off the RTC for logging and use a non-blocking wait for the polling/logging. 
 * 
 * Libraries:
 * https://github.com/matmunk/DS18B20
 * IDE built in SD card/SPI library
 * 
 * Sensor: 
 * https://www.ibuttonlink.com/products/t-sense-temperature-sensor
 * which has this device within.. 
 * https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf
 * 
 * Hookup:
 * You'll need a pullup resistor from 5V to pin 2
 * ibutton hookup:
 * 1 - GND
 * 2 - 5VDC
 * 3 - NC
 * 4 - Arduino Pin 2 (w/ Pullup)
 * 5 - GND
 * 6 - NC
 * 7 - NC
 * 8 - NC
 * 
 *  SD card attached to SPI bus as follows:
 * MOSI - pin 11
 * MISO - pin 12
 * CLK - pin 13
 * CS - pin 4 
 * 
 */

#include <DS18B20.h>
#include <SPI.h>
#include <SD.h>


DS18B20 ds(2);    //pin 2

const int chipSelect = 4;

void setup() {
  Serial.begin(115200);
  delay(100);

  Serial.println("----------------------------------------");
  Serial.println(" ");
  Serial.println("DS18B20 / iButtonLink Demo");
  Serial.print("Devices: ");
  Serial.println(ds.getNumberOfDevices());
  Serial.println(" ");
  Serial.println("----------------------------------------");
   Serial.print("Initializing SD card...");

  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don't do anything more:
    while (1);
  }
  Serial.println("card initialized.");
}

void loop() {
  int i_address;
  Serial.println("----------------------------------------");
  while (ds.selectNext()) {
    String str_dataString = "";
    switch (ds.getFamilyCode()) {
      case MODEL_DS18S20:
        Serial.println("Model: DS18S20/DS1820");
        break;
      case MODEL_DS1822:
        Serial.println("Model: DS1822");
        break;
      case MODEL_DS18B20:
        Serial.println("Model: DS18B20");
        break;
      default:
        Serial.println("Unrecognized Device");
        break;
    }

    uint8_t address[8];
    ds.getAddress(address);
    
    Serial.print("Address:");
    for (uint8_t i = 0; i < 8; i++) {
      Serial.print(" ");
      Serial.print(address[i]);
      str_dataString += String(address[i]);
    }
    Serial.println();
/*
    Serial.print("Resolution: ");
    Serial.println(ds.getResolution());

    Serial.print("Power Mode: ");
    if (ds.getPowerMode()) {
      Serial.println("External");
    } else {
      Serial.println("Parasite");
    }
*/
    Serial.print("Temperature: ");
    Serial.print(ds.getTempC());
    Serial.print(" C / ");
    Serial.print(ds.getTempF());
    Serial.println(" F");
    
    str_dataString += ",";
    str_dataString += String(ds.getTempC()); 
    File dataFile = SD.open("datalog.txt", FILE_WRITE);
    
    if (dataFile) {
        dataFile.println(str_dataString);
        dataFile.close();
        Serial.println(str_dataString);
    }  else {
        Serial.println("error opening datalog.txt");
    }
    Serial.println("        *****       ");
    Serial.println(); 
  }

  delay(30000);
}

Happy Making!

eBay Mini-vacuum Pump

Quick version: Hey this little thing works and seems practical for robotics, specifically the Pop Can Challenge.

I had to add “mini” to the title of this post, calling this a vacuum pump seems odd when you’ve played around with big pumps. Which leads me to make a mental note to share some information my industrial vacuum pump sometime; my big pump is currently at the SnoCo Makerspace but it seems it gets used as hold-down weight on glue-ups more than it’s intended use but at least it’s getting some love.

I moved workshops; I swear this is related… The kids are at an age were it’s hard for me to get out to my workshop for very long and Melissa works in the evenings right now so I just wasn’t getting any fun-stuff done. I’ll shoot another workshop video… soon-ish. I’ve been slowly filtering through my bins of incomplete or never-started projects in and sorting through it all to bring some organization into my “inside workshop”. In digging through the bins I recently came across most of this eBay purchase: https://ebay.us/2L8SOa . If you want to skip on clicking the link it’s a small motor/vacuum pump with a suction cup grabber. I bought this for PopBot after the 2019 Robothon. I put this aside because I’ve been working on PopBot and a second marine-based robot platform for the last two months. PopBot is getting a deep drive because the SRS Robothon (2020) https://robothon.org/ has been cancelled this year. The thought is I might be able to grab the PopCan with a suction cup instead of actively grabbing it, or in my case I was going to sort hug it/lasso the pop can; time will tell on this. My initial concern is current draw, thankfully thing only pulls a couple hundred milliamps and then it’ll hold it’s suction fairly well for a while. I noticed a solid drop off in current after the suction was “successful”. I would have thought it opposite but I guess based on looking at current curves on squirrel cage fans and seeing them unload without air flow I’ll accept it without figuring out why. My goal is to grab the can with a pair of suction cups, drop the motor PWM or turn it off once the suction is maintained (as determined by current) and then just provide a couple moments of pumping to maintain suction while transporting the can. For testing I came up with a quick little circuit with a Pololu DC motor driver (#2961) and an Adafruit i2c IN219 current sensor breakout board… don’t mind all the other stuff strapped to the MEGA in the photo below. It was on my bench for some sensor fusion testing. The INA219 is hooked up to the i2c ports (20/21) on the MEGA2560 and the motor driver is getting a PWM drive from Pin 6. I didn’t need to use the enable or direction, I just sunk the enable low. The amount of suction is quite adequate if you’re a 14 year old boy trying to get popular by giving yourself a hickey…. this is not recommended of course and mostly a guess as I have 4-day-old vacation stubble so there is no sense in trying.

The code for testing is at the end of the post, anyone with a couple hours of experience with Arduino IDE could whip this out in 10 minutes but just in case you were hoping to save 9-1/2 minutes…

/*  @chasihler iradan.com
 * 
 * 0.1 2020/08/20 Test
 * 
 * INA219 test w/ Vacuum Pump
 * Most of this is from the adafruit library example. 
 * 
 */


#include <Wire.h>
#include <Adafruit_INA219.h>

Adafruit_INA219 ina219;

int motor_pwm_pin = 6;
int motor_enable_pin = 7;

int int_stop = 0;
int int_lowSpeed = 950;
int int_highSpeed = 1023;

void setup() {
  Serial.begin(115200);
    
  pinMode(motor_pwm_pin, OUTPUT);
  pinMode(motor_enable_pin, OUTPUT);

    if (! ina219.begin()) {
      Serial.println("Failed to find INA219 chip");
        while (1) { delay(10); }
    }
      //ina219.setCalibration_32V_1A();
      //ina219.setCalibration_16V_400mA();
}

void loop()  {
  float shuntvoltage = 0;
  float busvoltage = 0;
  float current_mA = 0;
  float loadvoltage = 0;
  float power_mW = 0;
  Serial.println("No Load Test");
  Serial.print("Bus Voltage:   "); Serial.print(busvoltage); Serial.println(" V");
  Serial.print("Shunt Voltage: "); Serial.print(shuntvoltage); Serial.println(" mV");
  Serial.print("Load Voltage:  "); Serial.print(loadvoltage); Serial.println(" V");
  Serial.print("Current:       "); Serial.print(current_mA); Serial.println(" mA");
  Serial.print("Power:         "); Serial.print(power_mW); Serial.println(" mW");
  Serial.println("");
  
  analogWrite(motor_pwm_pin, int_lowSpeed);
  delay(1000);

  shuntvoltage = ina219.getShuntVoltage_mV();
  busvoltage = ina219.getBusVoltage_V();
  current_mA = ina219.getCurrent_mA();
  power_mW = ina219.getPower_mW();
  loadvoltage = busvoltage + (shuntvoltage / 1000);

  Serial.println("Low Speed Test");
  Serial.print("Bus Voltage:   "); Serial.print(busvoltage); Serial.println(" V");
  Serial.print("Shunt Voltage: "); Serial.print(shuntvoltage); Serial.println(" mV");
  Serial.print("Load Voltage:  "); Serial.print(loadvoltage); Serial.println(" V");
  Serial.print("Current:       "); Serial.print(current_mA); Serial.println(" mA");
  Serial.print("Power:         "); Serial.print(power_mW); Serial.println(" mW");
  Serial.println("");
    
  delay(1000);
  analogWrite(motor_pwm_pin, int_stop);  //stop
  delay(5000);
  analogWrite(motor_pwm_pin, int_highSpeed);
  delay(1000);

  shuntvoltage = ina219.getShuntVoltage_mV();
  busvoltage = ina219.getBusVoltage_V();
  current_mA = ina219.getCurrent_mA();
  power_mW = ina219.getPower_mW();
  loadvoltage = busvoltage + (shuntvoltage / 1000);
  
  Serial.println("Full Speed Test");
  Serial.print("Bus Voltage:   "); Serial.print(busvoltage); Serial.println(" V");
  Serial.print("Shunt Voltage: "); Serial.print(shuntvoltage); Serial.println(" mV");
  Serial.print("Load Voltage:  "); Serial.print(loadvoltage); Serial.println(" V");
  Serial.print("Current:       "); Serial.print(current_mA); Serial.println(" mA");
  Serial.print("Power:         "); Serial.print(power_mW); Serial.println(" mW");
  Serial.println(""); 
     
  delay(2000);
  analogWrite(motor_pwm_pin, int_stop);  //stop
  delay(10000);
}

Programming ESC with Arduino

The story: I hit a break wall with ODrive. ODrive is an open source brushless DC motor (BLDC) driver built with robotics in mind (my application..). I don’t have faith in the project and after months of trying to make it fit my application I’m abandoning it. It’s painful to spend that kind of money on a product (two even!) … but I’m not hopping back on the Stepper bandwagon just yet. I’ll see if I can put my brushless DC motors to use on PopBot 0.5.

First step was deciding on if I could use an off the shelf ESC or buy one. I purchased a RC “rockcrawler” driver as I assumed the firmware would be most compatible with my application. The car and boat ESCs have forward and reverse speed by splitting the PWM servo input in half. While waiting on shipping I found an ESC for a boat and a few for quads in one robot junk bins. Quads are single directions but the boat one was good enough for testing. It had no torque in the low end but that’s not a surprise based on the application with the motor type. I needed a way to program this ESC without a controller and receiver. Programming is typically performed w/ the receiver/controller by pushing the speed to min-max in a certain order. Well that can be done with the arduino of course. Here is a super simple piece of code for you if you don’t want to reinvent the wheel. This will also allow you to control your ESC once it’s programmed and you can uncomment my basic acceleration code if desired.

Hook up the ESC control signals (servo input). On the ESC the white (signal in, sometimes I think the alternate color is orange?) to digital output 9 on the Arduino Uno or Mega. Tie the black (or brown) wire to one of the grounds. DO NOT HOOK UP RED. We don’t need the power from the ESC.. it’s usually not something we want anyways (like 6V… ).

You’ll need this library. Download it and place the uncompressed directory in your Arduino libraries directory.

https://github.com/maxpowel/ESC

/*
 * Charles Ihler, iradan.com
 * 2020-04-27 build from example of library. 
 * 
 * Open the serial monitor... enter 0 (and enter) for reverse
 * 1 for foward and 2 for idle/stop.. 
 * Most ESCs want a motor hooked up or warn of damage.. make sure the motor is safe and can't spin off and hurt something. 
 * 
 */

#include <Servo.h>
#include "ESC.h"



ESC esc(ESC::MODE_FORWARD_BACKWARD);


int sel = 0;
String ssel;

void setup() 
{
  Serial.begin(115200);  
  pinMode(LED_BUILTIN, OUTPUT);
  esc.attach(9); //change to some other PWM pin if required

} 

void output_high() {
   digitalWrite(LED_BUILTIN, HIGH);
   esc.setDirection(ESC::FORWARD);
   esc.setSpeed(500);   //comment this out and uncomment below for acceleration. When test running motor.
   //for (int i = 0; i <= 150; i++) {
   //   esc.setSpeed(i);
   //delay(25);
   //}
}
void output_low() {
  digitalWrite(LED_BUILTIN, LOW);
  esc.setDirection(ESC::BACKWARD);
  esc.setSpeed(500);   //comment this out and uncomment below for acceleration. When test running motor.
  //  for (int i = 0; i <= 150; i++) {
  //    esc.setSpeed(i);
  //  delay(25);
  //}
}
void output_n() {
  digitalWrite(LED_BUILTIN, LOW);
  esc.setDirection(ESC::BACKWARD);
  esc.setSpeed(0);
}
void loop() 
{
    Serial.print("Forward (1), Reverse (0), Stop/N(2)?(1/0/2): "); 
    while (Serial.available() == 0) {}  
    ssel = Serial.readString();  
    Serial.print(" --> ");
    Serial.println(ssel);
    sel = ssel.toInt();
    if (sel == 1) {
      output_high();
      Serial.println("ON!");
    }
    if (sel == 0) {
      output_low();
      Serial.println("OFF.");
    }
    if (sel == 2) {
      output_n();
      Serial.println("Neutral");
    }
  delay(100);

} 
The setup project with motor removed.

Enjoy…

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