Translate Arduino code to microPython

[JHN]

Hello, I have an issue when i tried to translate Arduino code to microPyhton, This is the code that i tried to translate:

/*
 * SN74HC165N_shift_reg
 *
 * Program to shift in the bit values from a SN74HC165N 8-bit
 * parallel-in/serial-out shift register.
 *
 * This sketch demonstrates reading in 16 digital states from a
 * pair of daisy-chained SN74HC165N shift registers while using
 * only 4 digital pins on the Arduino.
 *
 * You can daisy-chain these chips by connecting the serial-out
 * (Q7 pin) on one shift register to the serial-in (Ds pin) of
 * the other.
 * 
 * Of course you can daisy chain as many as you like while still
 * using only 4 Arduino pins (though you would have to process
 * them 4 at a time into separate unsigned long variables).
 * 
*/

/* How many shift register chips are daisy-chained.
*/
#define NUMBER_OF_SHIFT_CHIPS   3

/* Width of data (how many ext lines).
*/
#define DATA_WIDTH   NUMBER_OF_SHIFT_CHIPS * 8

/* Width of pulse to trigger the shift register to read and latch.
*/
#define PULSE_WIDTH_USEC   5

/* Optional delay between shift register reads.
*/
#define POLL_DELAY_MSEC   1

/* You will need to change the "int" to "long" If the
 * NUMBER_OF_SHIFT_CHIPS is higher than 2.
*/
#define BYTES_VAL_T unsigned long

int ploadPin        = 5;  // BLUE - Connects to /PL aka Parallel load aka latch pin the 165
int clockEnablePin  = 9;  // not used - Connects to Clock Enable pin the 165 (should always be low)
int dataPin         = 6; // YELLOW - Connects to the Q7 aka MISO pin the 165
int clockPin        = 7; // PARPEL - Connects to the Clock pin the 165

BYTES_VAL_T pinValues;
BYTES_VAL_T oldPinValues;

/* This function is essentially a "shift-in" routine reading the
 * serial Data from the shift register chips and representing
 * the state of those pins in an unsigned integer (or long).
*/
BYTES_VAL_T read_shift_regs()
{
    long bitVal;
    BYTES_VAL_T bytesVal = 0;

    /* Trigger a parallel Load to latch the state of the data lines,
    */
//    digitalWrite(clockEnablePin, HIGH);
    digitalWrite(ploadPin, LOW);
    //delayMicroseconds(PULSE_WIDTH_USEC);
    digitalWrite(ploadPin, HIGH);
//    digitalWrite(clockEnablePin, LOW);

    /* Loop to read each bit value from the serial out line
     * of the SN74HC165N.
    */
    for(int i = 0; i < DATA_WIDTH; i++)
    {
        bitVal = digitalRead(dataPin);

        /* Set the corresponding bit in bytesVal.
        */
        bytesVal |= (bitVal << ((DATA_WIDTH-1) - i));

        /* Pulse the Clock (rising edge shifts the next bit).
        */
        digitalWrite(clockPin, HIGH);
        //delayMicroseconds(PULSE_WIDTH_USEC);
        digitalWrite(clockPin, LOW);
    }

    return(bytesVal);
}

/* Dump the list of zones along with their current status.
*/
void display_pin_values()
{
    Serial.print("Pin States:\r\n");

    for(int i = 0; i < DATA_WIDTH; i++)
    {
        Serial.print("  Pin-");
        Serial.print(i);
        Serial.print(": ");

        if((pinValues >> i) & 1)
            Serial.print("HIGH");
        else
            Serial.print("LOW");

        Serial.print("\r\n");
    }

    Serial.print("\r\n");
}

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

    /* Initialize our digital pins...
    */
    pinMode(ploadPin, OUTPUT);
    pinMode(clockEnablePin, OUTPUT);
    pinMode(clockPin, OUTPUT);
    pinMode(dataPin, INPUT);

    digitalWrite(clockPin, LOW);
    digitalWrite(ploadPin, HIGH);
    digitalWrite(clockEnablePin, LOW);
    /* Read in and display the pin states at startup.
    */
    pinValues = read_shift_regs();
    display_pin_values();
    oldPinValues = pinValues;
}

void loop()
{
    /* Read the state of all zones.
    */
    pinValues = read_shift_regs();

    /* If there was a chage in state, display which ones changed.
    */
    if(pinValues != oldPinValues)
    {
        Serial.print("*Pin value change detected*\r\n");
        Serial.println(pinValues);
        display_pin_values();
        oldPinValues = pinValues;
    }

    delay(POLL_DELAY_MSEC);
}

My translated code:

from machine import Pin
import utime
# How many shift register chips are daisy-chained.
NUMBER_OF_SHIFT_CHIPS = 3

# Width of data (how many ext lines)
DATA_WIDTH = NUMBER_OF_SHIFT_CHIPS * 8

# Width of pulse to trigger the shift register to read and latch.
PULSE_WIDTH_USEC = 5

# Optional delay between shift register reads.
POLL_DELAY_MSEC = 1

pinValues = 0
oldPinValues = 0



def read_shift_regs():
    bitVal = 0
    bytesVal = 0
    ploadPin.value(0)
    utime.sleep_us(PULSE_WIDTH_USEC)
    ploadPin.value(1)

    for i in range(DATA_WIDTH):

        bitVal = dataPin.value()
        # Set the corresponding bit in bytesVal.
        print(i,bitVal,bytesVal)
        bytesVal |= (bitVal << ((DATA_WIDTH-1) - i))
        clockPin.value(1)
        utime.sleep_us(PULSE_WIDTH_USEC)
        clockPin.value(0)
    return bytesVal

def display_pin_values():
    print("Pin states: ")
    for i in range(DATA_WIDTH):
        if(pinValues >> i & 1):
            print(" Pin-" ,i ,": HIGH")
        else:
            print(" Pin-" ,i ,": LOW")
    print("\r\n")


#Set up
ploadPin = Pin('P2', mode=Pin.OUT) #Blue
clockPin = Pin('P14', mode=Pin.OUT) #Purple
dataPin = Pin('P4', mode=Pin.IN) #Yellow


clockPin.value(0)
ploadPin.value(1)
pinValues = read_shift_regs()
display_pin_values()
oldPinValues = pinValues
while True:
    pinValues = read_shift_regs()
    if(pinValues != oldPinValues):
        print("Pin value change detected*\r\n")
        print(pinValues)
        display_pin_values()
        oldPinValues = pinValues
    utime.sleep_ms(POLL_DELAY_MSEC)

The issue is that i only get 0 from the sensors. So the serial communication does not work like i thought.

[Gijs]

Hi!
s
I checked your code and in python, it seems to be missing the clockEnablePin, if you set it to low, it activates the SN74HC165N chip
I believe some of the pins on the esp32 device float high, but im not sure that is the issue in this case.
Let me know if that makes it work!

Gijs

[JHN]

This post is deleted!

[JHN]

@Gijs

Hello! that pin are not needed, infact my code is working, one hardware pin "p2" had some issue, it is constant 3.3V which means that the ploadPin are not toggled. The code awill hopefully be uploaded on Git!