For simple microcontroller prototyping there is no problem program chip from computer by using one of many programmer adapter. Setting thing up takes a bit of time, but for up to several chips this is not a big problem. But when your projects scale up a bit, flashing issue may become annoying. When you need to flash lots of them you start for more robust solution. The guys from Solderlab grew to the point where lots of AVRs need to be programmed so instead of doing this old fashion way they built an auto programmer.
Their auto programmer is capable of programming AVR microcontrollers automatically. All you need is to put hex file in to micro SD card and once powered it can flash chip automatically. Programmer can work with DIP AVR chips also program via ISP. It has a Nokia 5510 LCD where navigation menu is displayed. Here you can select what to do including: flashing, reading, reading fuses and other stuff. LCD also displays progress bar while programming and error messages if there are some. Same or more information it also outputs to UART where with terminal program you can control and monitor programming process. In order to program smoothly, hex files has to be prepared with addition header information from where programmer takes information about chip to be programmed, fuse settings, chips flash size and flash page size. Once set you can start piling chips pretty fast.
Numitron tubes are special type of displays, where digits are constructed out of segments like in 7-segment LED displays. They can be driven with standard 74HC595 shift registers. Numitron indicators require about 20mA of current so interfacing them to microcontrollers is fairly easy. Kalshagar have built really nice four Numitron digits based digital clock.
He wanted clock to be modular so that different parts could be reused in other projects if needed. To do so, he split design in to two boards – a display board which carries only tubes and driving circuit; while another part where microcontroller, RTC and backup battery is. He has done several versions of board and enclosure while eventually he stayed with rusty metal casing which looks really great.
When starting new microcontroller based project you start looking for suitable platform to start with. Many times in small projects Arduino takes over because it is popular, simple and have great ecosystem with tons of libraries and project examples. It is hard to beat this, but possible…
Pieter have sent us an update on their development board which runs on Atmega328p microcontroller. It doesn’t follow Arduinoe standards, but rather focus on other things that make easier development and testing. Their scorpion development board have all necessary elements like efficient power regulator, USB-USART bridge, buzzer, 512K dataflash, LED, push button, ADC scale and filtering. The rest of connection interfaces and GPIO are positioned on the side of PCB.
But this is not a board what makes it great. They’ve done great work on building software framework to develop embedded programs clean and efficiently. Firmware library has been developed to be portable between 8-bit, 16-bit and 32-bit systems. Framework focuses on good developing practices that evolved during years of coding. Several great project examples will get you started in no time and in time you will start appreciate the hard work they’ve put in.
Most PCs have have option that enable booting it on keyboard input. This gives ability for interesting hacks like knock enabled PC power up. Joonas have built a simple Attiny45 device that detects knock and sends PS/2 command to PC to turn it on. Knock is detected with piezo buzzer that is used as knock sensor. Since circuit is connected to PS/2 interface, it also provides power supply.
knocks are detected by reading piezo sensor with microcontroller ADC input. ADC is implemented to sense signal level that is over threshold. And in order to to detect three successive knocks there is a timer based counter implemented. This is really simple implementation that can impress your friends.