Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

DRUM-MACHINE 2.0

DRUM-MACHINE is a device which is modelled on classic machines like the ROLAND TR808. However, this version is digital and not analogue in nature and only require a single microcontroller which is PIC24 in this case to work. The PIC has 128kb of memory which is enough to store audio samples. Another advantage of PIC24 is it is capable of running at 40MHZ of frequency which is quite fast. However the author switched to PIC32 in the later stages as he couldn’t get the prototype working. The advantage of PIC32 was that the user has full-access to flash memory s so it made the code part easier. Talking about the DRUM, the drum features 16 different instrument which are stored in flash memory along with 16 step patters with 16 pattern per song. It also has 8 sample polyphony, which are sample from classic drum machines. Another advantage is it can drive audio headphones directly or a speaker via a TPA301 IC. The data is displayed using a Nokia 5110 LCD and there are also a combination of 20 LED’s… Continue reading

PIC software SPI driven nokia 5110 LCD

Nokia 5110 graphical lcd is convenient to use because of SPI interface. So it is one of favorite LCDs in embedded projects. Following project is a interfacing example of this LCD to PIC16F84 microcontroller. The problem is that this PIC microcontroller lacks SPI interface so there is only one way to drive this LCD – use software based SPI communications. Source code is written in ASM language. So C lovers may find it tricky to use. In other hand ASM has a big advantage versus C in small MCUs. So you’re free to choose. Continue reading