Inductance Inductance “rolls off” with increasing current and the way this happens depends on the material: Iron powder, molybdenum permalloy powder (MPP), sendust and amorphous powder that employ a distributed air gap Inductance roll off starts at very low current levels and continues in an almost linear manner as the current is increased. The peak […]
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DisplayPort
Multiple Monitor Support This is aimed particularly at mobile devices with limited connector space. Backwards Compatibility Dual-mode DisplayPort (also known as DisplayPort++) can directly output single-link HDMI and DVI signals using a simple passive adapter that adjusts from the different connector and the lower voltages used by DisplayPort. When a DVI or HDMI passive adapter is […]
Elect Microphones
Good Resources EEVBlog 611 – Great video in a series of videos about microphones Voltage Requirement The characteristics of elect microphones are typically specified with a 2K resistor up to +5V. However you can power with a lower voltage. Many will work down to 1.2V, and some down to 0.8V (see the eevblog video) – […]
6800 and 8080
These are two different parallel microprocessor interface methods: Intel 8080 Uses: nRD and nWR Motorolla 6800 Uses: RD/nWR and E.
MIDI Comms
Good resources hinton-instruments.co.uk/reference/midi/protocol/ midi.org/techspecs/midimessages.php Communications Overview Command bytes Always 128 or greater (0x80 to 0xFF) Includes things like note on, note off, pitch bend, etc. Data bytes Always less than 127 (0x00 to 0x7F) Includes things like the pitch of the note to play, the velocity, or loudness of the note, and amount of pitch […]
Midi PC Development Apps
Midi Test Interfaces We've used the Proxima Direct USB to Midi Cable under Windows 7 64bit without any problems to test Midi RX from embedded devices we're developing. Development Applications MIDI-OX
MIDI General
UART 31.25KBaud (+-1%), asynchronous, 1 start, 8 data, 1 stop (31250-8-N-1) 320 uS per byte. Start bit is 0, stop bit is 1 Electrical Interface http://www.midi.org/techspecs/electrispec.php Interface 180° five-pin DIN connector MIDI devices are joined together in chains, passing the same message along a serial chain. Up to 16 receivers may be joined on one chain. […]
RFID Reader Antennas
A Word Of Caution… RFID Antenna designs can require optimsation for the particular RFID tags you are using, especially if you are using a small antenna coil. When evaluating a RFID solution, especially a components based solution, don't just assume it will all work. Test using the tags you plan to actually use, test the maximum and minimum read range […]
RFID Tag Types
Low Frequency vs High Frequency Low frequency readers are often cheaper (although not always due to the mass production of high frequency). Low frequency writable tags typically have smaller memory and the data transfer between read and tag is slower due to the lower frequency. High frequency tags can often have a shorter range than low […]
Heatsinks General
Heatsink Colour In natural convection a black or dark colored heatsink will perform 3% to 8% better than an aluminum heatsink in its natural silverish color. This is due to dark colors radiating heat more efficiently. In forced air applications, surface color does not increase a heatsink's performance due to the increase in convection. A […]