# ClOCkTAL: For When Reading A Clock Is Just Too Easy

Over on Hackaday.io, [danjovic] presents clOCkTAL, a simple LED clock for those of us who struggle with the very concept of making it easy to read the time. Move aside binary clocks, you’re easy, let’s talk binary coded octal. Yes, it is a thing. We’ll leave it to [danjovic] to describe how to read the time from it:

Do not try to do the math using 6 bits. The trick to read this clock is to read every 3-bit digit in binary and multiply the MSBs by 8 before summing to the LSBs.

Simple. If you’re awake enough, that is. Anyway, we’re a big fan of the stripped-down raw build method using perf board, and scrap wood. No details hidden here. The circuit is straightforward, being based on a minimal configuration needed to drive the PIC16F688 and a handful of LEDs arranged in a 3×4 matrix.

An interesting detail is the use of Bresenham’s Algorithm to derive the one event-per-second needed to keep track of time. And no, this isn’t the more famous Bresenham’s line algorithm you may be more familiar with, it’s much simpler, but does work on the same principle of replacing expensive arithmetic division operations with incremental errors. The original Bresenham’s Algorithm was devised for using with X-Y plotters, which had limited resolution, and was intended to allow movements that were in an imperfect ratio to that resolution. It was developed into a method for approximating lines, then extended to cover circles, ellipses and other types of drawables.

# Getting Started With STM8

There are so many different CPUs today and often the hardest thing about using any of them is getting started and gathering the right software tools. If you’ve ever eyed up the very inexpensive STM8 processor, you’ll want to check out [Shane Burrell’s] video (see below) about how to get started with the STM8.

The STM8 isn’t a 32-bit processor — you could probably guess that from the name. [Shane] uses SDCC (small device C compiler) to target the little chip. He also shows how he manages a fairly substantial piece of code and how he controls the build process.

# Smaller Cheaper Arduino

Well, honestly, [Michael Mayer’s] STM8 Arduino (called Sduino) isn’t actually much to do with the Arduino, except in spirit. The STM8 is an 8-bit processor. It is dirt cheap and has some special motor control features that are handy. There’s a significant library available for it. However, it can be a pain to use the library and set up the build.

Just like how the Arduino IDE provides libraries and a build system for gcc, Sduino provides similar libraries and a build system for the sdcc compiler that can target the STM8. However, if you are expecting the Arduino’s GUI or a complete knock off of the Arduino library, you won’t get that.

# Stcdude Is Linux Friendly ISP Programming Software For STC 8051 Chips

[Andrew] picked up a handful of these big STC 8051 chips for a song and dance. The problem he has with them is the clunky VB6 programming software that only wants to run on a Windows box. He buckled down and wrote his own programming software called stcdude. As you have probably guessed, it’s meant to perform the same open-source functions that avrdude does for AVR chips. It can be used in conjunction with the Small Device C Compiler (SDCC).

It uses an API which is based on Lua script. We think this is to make it easy to interface your own hardware programmer with the software. The package is still quite early in development but it is working and even implements the ability to poll and identify the type of chip based on its stored hardware database. It sounds like he could use a hand. The stock software must still be used for setting the MCU options. We’re not really familiar with the 8051 family but we’d bet that is akin to setting the fuses on the AVR chips. Please let us know in the comments if we’re wrong about that.

# How-to: Program PICs Using Linux

Arguably, Microchip’s PIC microcontrollers do not get enough posts here. One of the drawbacks for some of us is that Linux support for PICs is not very well known. The information is out there, but no one has laid out the process of going from writing C code to programming a chip. Written for Linux users that are familiar with microcontrollers, basic circuits, the C programming language, and can read a datasheet, this how-to should get you up and programming a PIC quickly with Linux.