Old app note from Macronix about accessing high density serial flash. Link here (PDF)
Many consumer products have converted or are converting from parallel flash to SPI serial flash. Generally, high end applications require higher memory density, but in the past, serial flash densities were limited to 128Mb due to addressing constraints.
USB OTG explained in this app note from Cypress Semiconductors. Link here
This application note discusses several aspects of OTG functionality. The note introduces end-applications and different types of cables and connectors involved with OTG. It also describes the OTG protocol state changes when both Mini-A and Mini-B devices are connected .The host negotiation protocol (HNP) and session request protocol (SRP), which are part of the OTG protocol, are also explained.
This project provides a simple breadboard adapter/breakout board for prototyping cartridges for the Acorn BBC Master and Acorn Electron 8-bit computers.
The design consists of two PCBs, the first plugs into the computer’s cartridge slot and the second is designed to plug along the edge of a standard 2.54mm pitch breadboard. The two boards are connected by a length of 50-way ribbon cable.
This project is about an open source, USB based, 10 digit seven segment display unit. This unit is specifically designed to work with POS systems and banking applications. Initially, this system is developed to work with PC based systems, and later it was modified to work with other platforms and applications.
Shawon Shahryiar over at Embedded Lab shared a how-to on making a SPL dB meter:
Sound needs a medium for propagation or travel. It can’t travel in vacuum. Normally air is that medium but sound can also propagate in liquids and other states of matter. I am not going to lecture on how sound travels and its properties as Wikipedia details everything well here. Everything we see around us has a measurement and a unit. In case of sound pressure, the unit is decibel. Our basic requirement is to be able to measure Sound Pressure Level (SPL) in decibel scale with a typical 8-bit microcontroller, an ordinary microphone and without involving complex algorithms.
Measurement of sound has a number of uses. For instance, monitoring sound pollution, security system, monitoring the quality of an amplifier, detecting sound profile of an environment, etc.
Hardened circuit protection against voltage spikes and surges tackled in this app note from Vicor. Link here (PDF)
Electrical systems in military vehicles are normally required to meet stringent transient requirements. Typical of these specifications is the MIL-STD-1275B. Although the specified levels of these surges and spikes are outside the capability of Vicors Maxi, Mini, Micro Series modules, it is quite possible, with simple circuitry, to make the 24V input (18 – 36V input range) DC-DC converter modules compliant to these specifications for the 28V vehicle voltage system. Other electro-magnetic compatibility requirements, such as MIL-STD-461E and/or DEF-STAN 59-41, apply to military vehicles, but these are outside the scope of this application note. In order to meet additional conducted emission requirements an input filter, preceding the transient protection circuit covered in this application note, will be required.
Driving 300 WS2812B RGB LED’s with “the 3 cent microcontroller” – the Padauk PMS150C.
The 3 cent Padauk PMS150C is.. Interesting to say the least. First of all there’s a lot this little MCU doesn’t do. It doesn’t have a lot of code space (1K Word), it doesn’t have a lot of RAM (64 bytes) and it doesn’t even do hardware multiplication. It doesn’t have an instruction for loading data from ROM either(Though there are ways of getting around this – but that’s a subject for another post). And of course – you can only program it ONCE.
Kenneth Finnegan shared a tip on using 0603 SMDs on the .1″ perf board:
As a quick little tip, when I’m prototyping circuits on 0.1″ perf board, I like using 0603 surface mount components for all of my passives and LEDs, since they nicely fit between the pads. This way I don’t need to bother with any wiring between LEDs and their resistors, since I can just use three pads in a row to mount the LED and their corresponding current limiting resistor and just need to wire the two ends to where they’re going.