23 lines
629 B
Plaintext
23 lines
629 B
Plaintext
BOM
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2N4401 NPN transistor
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RS-232/TTL Level Shifter
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Male DE9 connector
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Connections
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Switch is from collector to emitter, governed by base
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4401 Collector - DE9 pin 2 (+5v)
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4401 Emitter - DE9 pin 7 (PB0*)
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4401 Base - Level Shifter out
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Level Shifter GND - DE9 pin 3 (GND) and External Power ground
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Level Shifter out - 4401 Base
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Level Shifter Vcc - (External Power)
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DE9 pin 3 (GND) - Level Shifter GND
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DE9 pin 7 (PB0*) - 4402 Emitter
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DE9 pin 2 (+5v) - 4402 Collector
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* Consider using PB1 instead of PB0; PB0 held high is like holding down the open-apple key, turns ctrl-reset into ctrl-openapple-reset all the time
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