https://www.t3ch.it/ 2026-09-20T15:52:07+00:00 https://www.t3ch.it/ https://www.t3ch.it/lib/exe/fetch.php?media=wiki:logo.png text/html 2022-07-02T09:21:33+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:7_segment_displays&rev=1656753693&do=diff PIC18: 7-segment displays 7-segment displays are an effective and still widely used way of displaying alphanumeric data. In fact they are quite simple, because they consist of 8 leds (decimal point included) connected in parallel and with the cathode (or anode) in common; by turning on specific leds ( text/html 2022-07-02T09:22:11+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:8x8_led_matrix_display_shift_registers&rev=1656753731&do=diff PIC18: 8x8 LED Matrix display and shift registers In this experiment we will use PIC 18F4550 little bro, the 18F2550; it has (mostly) the same features as its oldest sibling but with a reduced number of I/O's, making it suitable when there is no need of many I/O ports. text/html 2022-07-02T09:22:36+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:branch_instructions&rev=1656753756&do=diff PIC18: branch instructions Skimming through the PIC 18F4550 istruction set we can see, among others, a bunch of branch instructions. What are they for and what's their relationship with the STATUS register? Let's see them in practice using some assembly code examples. This will also be a nice occasion to do a bit of simple HEX math. text/html 2022-07-02T09:24:22+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:connecting_ps_2_keyboard&rev=1656753862&do=diff PIC18: Connecting to a PS/2 keyboard With the advent of the USB protocol in the 90's many peripherals' manufacturers abandoned the previous protocols and connections to adopt it as a unifying standard; in the past printers mostly used parallel/Centronics ports, modems were serials, scanners could use SCSI interfaces, which often required a daughter board to be placed inside the cabinet of PC's, and mice and keyboards had to be connected to PS/2 ports. USB slowly emerged and unified all the con… text/html 2022-07-02T09:23:27+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:connecting_ps_2_mouse&rev=1656753807&do=diff PIC18: Connecting to a PS/2 mouse In a previous article we saw how to connect to a PS/2 keyboard. Here we are completing topic by describing how a PS/2 mouse can be interfaced to a PIC micro. Connections remain the same; there are still four wires that carry +5V, ground, Data and Clock signals. Plus the same mini-DIN (male and female) connectors are used. Similar to the above article in the following articles text/html 2022-07-02T09:24:57+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:guide_assembling_linking_programming_linux&rev=1656753897&do=diff PIC18: a guide to assembling, linking and programming with Linux Have you ever wondered how to program Microchip PICs in assembly under Linux? Here's a quite in-depth introduction that tries also to show the inner workings of the PIC18 family architecture. text/html 2022-07-02T09:25:32+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:i2c_eeprom_dump_via_rs_232_serial&rev=1656753932&do=diff PIC18: I2C EEPROM dump via RS-232 serial In this project we are going to implement two different buses to get data from and to a PIC18: serial RS-232 and I2C bus. For an intro to I2C please see Wikipedia; the scenario that was implemented below is the one in which the PIC operates in _master mode_. text/html 2022-07-02T09:25:52+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:pcf8563_i2c_real_time_clock_calendar&rev=1656753952&do=diff PIC18: PCF8563 I2C Real Time Clock Calendar The Freedom II demoboard includes also a PCF8563 I2C Real Time Clock Calendar (RTCC); let's learn how to use it to display time and date and set an alarm. As soon as the RTCC is powered on it begins keeping time and date, starting from 00:00 (hh:mimi:ss) and from 00/00/00 (dd/momo/yy); the chip makes available those data thanks to a bunch of _registers_, which can be seen on the right of the below image: text/html 2022-07-02T09:26:10+00:00 Anonymous (anonymous@undisclosed.example.com) https://www.t3ch.it/doku.php?id=content:pic:ultrasonic_sensor&rev=1656753970&do=diff PIC18: Ultrasonic sensor In this article we are going to experiment with an ultrasonic sensor, the HC-SR04; it seems quite known and common, especially in the Arduino community, maybe because it is quite cheap and simple to operate. Wanna discover how we can use it to measure the distance of an object, by interfacing it to the Freedom II development board? Yes? Coool! So