Subscribe
Login
RSS feed: Daily tech news Daily tech news
  • Scientists are building a microscope powered by a quantum computer
    Scientists are combining an electron microscope with a quantum computer to squeeze far more information from each electron. The approach could reveal faint details with fewer electrons, helping protect fragile samples that conventional microscopy can damage.
  • Tiny nanolaser could cut computer energy use in half
    Scientists have created an ultra-small nanolaser that could eventually allow microchips to transmit information with light instead of electricity, potentially making computers faster while cutting energy use roughly in half. Thousands of the lasers could fit on a single chip, opening possibilities for more efficient data centers, smartphones, and advanced medical sensors.
  • Quantum oscillations defy expectations in this exotic material
    Scientists have uncovered an unusual form of electron behavior in zirconium pentatelluride, a quantum material that can act as both an insulator and a conductor. Under temperatures near absolute zero and magnetic fields reaching 60 tesla, electrons produced quantum oscillations that continued even after conventional physics predicted they should disappear.
  • A new recipe unlocks “impossible” nanocrystals for LEDs, implants, and superconductors
    Scientists have cracked a long-standing chemistry problem, creating nanocrystals from tough metal nitrides that were previously extremely difficult to produce at this scale. The breakthrough could turn familiar materials used in LEDs, implants, and superconductors into building blocks for flexible electronics, printable devices, and other technologies.
  • Scientists turn one of the hardest plastics to recycle into high-performance engine lubricant
    Researchers have discovered a way to turn notoriously difficult-to-recycle PVC plastic into a key ingredient used in high-performance lubricants such as engine oil. The technique could give mountains of plastic waste a valuable second life while making lubricant production more sustainable.
  • Scientists catch a hidden electronic state forming in just 30 femtoseconds
    Scientists watched a light-triggered hidden state form inside a material in only 30 femtoseconds, revealing a step that had never been seen before. The material first entered a fleeting electronic state in which its bonds reorganized in a repeating pattern, followed by tiny atomic shifts. This ultrafast pathway could offer a new way to control […]
Core tutorial Embedded systems

Pin diagram of the PIC16F877A microcontroller

by Florius
3977 1 min 0
Illustration showing the 40-pin layout of the PIC16F877A microcontroller. Each pin is labeled with its corresponding port (e.g., RA0, RB7), alternate functions (such as ADC inputs, UART, SPI, I2C), and power supply pins (VDD, VSS). Used to guide hardware interfacing in MPLAB X IDE projects.

Pin diagram

The important pins

For accurate and dependable information, referring to the datasheets provided by Microchip Technology is advisable; these documents can be accessed here. Additionally, a brief overview of the pin diagram is recommended, detailing their functionalities and locations. Let’s begin by outlining the pins essential either for MCU operation or Pickit3 programmer-based programming:

  1. Pin 1 houses the MLCR/VPP, serving as a microchip reset mechanism.
  2. Pins 11 and 32, designated as VDD, necessitate a voltage range of 3.3V to 5V for proper functioning.
  3. Pins 12 and 31, denoted as VSS, are connecting to the ground
  4. To establish a connection with the Pickit3 programmer, pins 40 and 39 host PGD and PGC, respectively.
  5. Pins 13 and 14, namely OSC1 and OSC2, deliver a stable clock signal to the microcontroller. When utilizing the Pickit3 programmer, connecting these pins is unnecessary, thanks to the internal oscillator within the programmer facilitating MCU programming.

The exact method to program with your PICKIT3 programming tool, can be found here.

Pin diagram of the PIC16F877A; Programming pins
Pin diagram of the PIC16F877A; Programming pins
Pickit3 programming pins
Pickit3 programming pins

Port structure in the PIC16F877A

The PIC16F877A has 5 ports, namely A to E, where each pin can be configured as an input or output. However, it is important to note that not all ports consist of the same number of bits, due to some pins being taken by VSS or VDD, for example. In detail, port A consists of 6 bits, ports B, C, and D have 8 bits, while port E consists of only 3 bits.

Apart from being used for General Purpose Input Output (GPIO), most pins on this MCU have dedicated roles for specific functions. For instance, some pins on port C function as the TX and RX pins for the UART communication module, enabling the transmission and reception of serial data. Additionally, analog input channels for the ADC module on ports A and E can convert analog signals into digital values, opening up opportunities for further processing. When choosing IO pins, check the requirements of your project adequately to make the best possible decisions.

Labeled diagram of the PIC16F877A microcontroller showing all 40 pins with their port names (RA0–RA5, RB0–RB7, etc.), analog inputs, digital I/O, and special functions like USART, SPI, I2C, ADC, and oscillator pins. Useful for hardware design and firmware development in embedded applications.
Post Views: 7,628

Leave a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

You may also like