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tiny_tnc [2014/09/04 14:31] (current)
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 +====== Tiny_TNC ======
 +Tiny TNC is a small interface allowing an Android or other phone with a standard headset jack to interface with a radio with a standard Speaker/Mic jack. In order to work, an external logic input must trigger the "​key"​ to transmit over the air. In it's current revision, the Tiny TNC only passes audio from the phone to the radio. Future versions may allow the phone to receive as well.
 +{{wiki:​TinyTNCv10PCB.jpg?​300|Top layer rendering of TinyTNC PCB.}}
 +The PCB for the Tiny TNC measures 1.5in x .75 in. 
 +*3 Pin header spaced at .1" for Power, Ground, and Key
 +*2 4 pin 4.5mm audio jacks for connecting phone to radio
 +*Opto-Isolated relay circuit for keying radio by 3.3v logic input
 +====Version 1 Bugs====
 +*Silkscreen too small overall.
 +*Silkscreen Diode orientation missing. ​
 +*Silkscreen "​Opto"​ inside footprint, change orientation marking to dot for simplification.
 +*Silkscreen values instead of "​R1"​ etc. 
 +*Alignment holes for audio jacks too small.
 +*Some sort of ground loop problem. ​
 +*Trim pot is worthless.
 +*Header holes are too big and not wide enough.
 +====Version 2 Fixes====
 +*Silkscreen Improvement
 +*Alignment holes for audio jacks
 +*Remove Trim Pot
 +*Install transformer,​ 2.2k resistor, and 100 ohm resistor to isolate circuits.
 +*Transformer:​ 553-1580-5-ND
 +*Update eagle part with bigger pads.
 +=====Parts List=====
 +{| class="​wikitable"​ style="​color:​ green;"​
 +!Part Number
 +|3 Pin Male Header
 +|10k Ohm 0603 SMD Resistor
 +|1k Ohm 0603 SMD Resistor
 +|10K Ohm Trimmer Pot
 +|Optoisolator with Darlington Driver - 1 Channel
 +|3.5mm 4 Conductor Audio Jacks SMD
 +|Transistor NPN SOT89
 +|3/8" Plastic Standoff
 +|Diode SOD80C
 +|1/4" Phillips Screw 4-40
tiny_tnc.txt ยท Last modified: 2014/09/04 14:31 (external edit)