Questions tagged [bit]
A bit (short for binary digit) is the smallest unit of data in a computer. A bit has a single binary value, either 0 or 1. Although computers usually provide instructions that can test and manipulate bits, they generally are designed to store data and execute instructions in bit multiples called bytes.
19
questions
3
votes
2answers
201 views
Form a signal from an array of bits
I need to reproduce with a digital pin of an Arduino such a key in the form of a sequence of 1's and 0's, where a one takes 2 ms high and 2 ms low, and a zero takes 1 ms high and 1 ms low.
int key =...
1
vote
1answer
126 views
Print 2 numbers stored in 24-bits in decimal format
An implementation function from the nice little Wiegand library YetAnotherArduinoWiegandLibrary prints a hexadecimal representation of a facility # & card # (8-bit facility #, 16-bit card #) — 24 ...
0
votes
2answers
287 views
LSB/MSB and shiftOut
Here is the shiftOut function code from wiring_shift.c
void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
{
uint8_t i;
for (i = 0; i < 8; i++) {
...
0
votes
2answers
115 views
need to compare if a byte is less than 80 hex
I am using an infrared sensor called OTI301. In its data sheet it says that in order to obtain object temperature and ambient temperature values I need to extract the binary information from the ...
1
vote
1answer
92 views
How to split a binary data to form two split binary data?
I want to split a received binary data into two binary data.
Take the following received binary data for instance:
uint32_t data = 0xFFFF0001;
In binary format it is: ...
-1
votes
1answer
42 views
Control 4 digital outputs with one switch
I want to control 4 digital outputs (d0, d1, d2, d3) with one switch. When the Arduino starts, they should all be in state LOW.
Now, after pressing the button once, d0 should get HIGH. Another push ...
1
vote
1answer
433 views
USing arrays, binary data and bitRead
This is my first manually typed code. I'm sure there may be some glaring "schoolboy errors" in it, so wondered if people could give it the 'once over' In particular, I have never used C++ arrays, ...
1
vote
1answer
136 views
Bit Number to Byte Value conversion (AVR Docs)
I have hard time to understand what this doc tells me: https://www.microchip.com/webdoc/AVRLibcReferenceManual/FAQ_1faq_use_bv.html
I has a macro called _BV that
convert a bit number (usually ...
0
votes
1answer
131 views
MXCHIP IoT DevKit too many initializers for 'unsigned char [0]
Question
Trying to call the Display draw API using the sample code for the azure logo bitmap sample code. I'm unable to reach a point where I can the API because breaks when constructing the bitmap ...
0
votes
2answers
189 views
Replace digitalWrite with a selective bitwise operation
I have the following code with digitalWrite I aim to write with bitwise operation only.
No portability concerns here whatsoever. (for atmega328p here)
#define DATAOUT 11//MOSI
byte commandbits = ...
3
votes
2answers
202 views
Testing Conditions on Port Bytes - ignoring certain bits?
Being new to testing byte and bit conditions, I feel like there has to be a better way to test for conditions/values on a byte (read from a port).
For example, I'm reading 8 bits from PORTK. I need ...
1
vote
4answers
4k views
Hex/Byte Reversing and Conversion
I'm working on an RFID system using a MFRC522 with this Library : https://github.com/miguelbalboa/rfid
Here's the code I have right now:
int A=(mfrc522.uid.uidByte[0]);
int B=(mfrc522.uid.uidByte[1]);...
-1
votes
1answer
814 views
transmit a sequence of bit using arduino uno [closed]
How do i code to transmit a sequence of bit using arduino uno?My project is about a transmitter and a receiver.Arduino as the transmitter and an application as the receiver.Light sensor will detect ...
0
votes
2answers
977 views
C++ Adding Two 16 bit binary numbers together
I am trying to add two 16 digit binary numbers together. Each binary number will have been entered by the user and saved as: int binaryOne[16] and int binaryTwo[16]. Originally,
int binaryOne[16] = {...
2
votes
3answers
167 views
Arduino status of bit
Is the a way to check the status of a bit in an arduino Uno?
Like how in Atmel AVR, there is bit_is_clear or bit_is_set
0
votes
1answer
424 views
How does Arduino UNO deal with bit shifting?
Explanatory comment: I'm a beginner. I'm examining the feasibly of bit shifting to the right 6 places to divide up the range of the Arduino ADC (has a range of 0 to 1023) to something much smaller. ...
0
votes
2answers
313 views
Encode & decode boolean values into a single integer?
I'm trying to record the state of some pins over time. To save memory, I'm thinking about encoding the pin states into a single integer, like this:
Pin 1: TRUE
Pin 2: FALSE
Pin 3: FALSE
Pin 4: TRUE
...
0
votes
2answers
196 views
Understanding bitwise operations [duplicate]
I am wondering what the second line of code does:
int16_t GyX;
GyX=Wire.read()<<8|Wire.read();
Also, how can I write the GyX value to EEPROM?
From what I understand, int16_t is a two-bytes ...
0
votes
2answers
97 views
Overflow in bit calculation [closed]
I'm having a double buffer to write data from sensors to SD card. inBuf points to the buffer that are written into (from sensors). The other buffer write data to SD card.
char buffer[2][BUFLEN];
...
