Short talk about some things I've done with microcontrollers (AVR mostly) including a high-altitude balloon.

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USB for programming
Digital ports
External power/Battery
Analog ports
Serial
ATMega328

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23. ANTENNA CONNECTOR
UHF RADIO
THERMOMETER
GPS MODULEVOLTAGE DIVIDER CONNECTOR FOR
SECOND THERMOMETER

24. Telemetry
50 bps RTTY FSK
In English…
One tone for 1
Another tone for 0
50 bits per second
400Hz difference between the tones
ASCII
$$GAGA1,5131,09:58:23,52.2354,0.09
40,3394,7.64,26.1,13.4,64*1E

25. Telemetry
50 bps RTTY FSK
In English…
One tone for 1
Another tone for 0
50 bits per second
400Hz difference between the tones
ASCII
$$GAGA1,5131,09:58:23,52.2354,0.0940,
3394,7.64,26.1,13.4,64*1E
Seconds since boot
UTC
Lat / Long
Altitude
Vertical rate m/s
Internal ℃
External ℃
Checksum

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31. SERIAL PORT

33. ATMega328P
Three wires needed:
+ve
GND
Data

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40. R2 R1 V0 Level
0 0 0 Sync
0 1 0.3 Black
1 0 0.6 Grey
1 1 1 White

42. No USB. Need FTDI cable
Digital ports
External power/Battery
Analog ports
Serial
ATMega328P

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48. RGB LED
Three wires needed:
+ve
GND
Data
Start bit
6-Bit Bulb Address
8-Bit Brightness
4-Bit Blue
4-Bit Green
4-Bit Red
Idle bus state: Low
Start Bit: High for 10µS
0 Bit: Low 10µS, High 20µS
1 Bit: Low 20µ, High 10µS
Shift register per LED

54. Only 142
connections to
solder!

65. ATtiny85
8K of Flash
512 byte of SRAM
512 bytes of EEPROM
5 I/O ports
ATmega32u4
32K of flash
2.5K of RAM