2.5 KiB
RGB LED Thermometer
Changelog
- 18.02.17: CHANGE: Add EEPROM_DEBUG defined block. Need to be compiled with -O3 Flag INFO: ledcolor==3 block is obsolete. Could be removed to save space
- 23.06.17: CHANGE: comment out ledcolor==3 block reduce brighness to 100 for green and red INFO: MicroCore 1.0.2 creates very small binary, suspious
- 25.05.18: CHANGE: reduce the used flash ADDED: max red temp per session FIXED: lowered red, green led intensity
Improvement
- bug fix where Blinking RED would not change led_color back --> global/local definiton
- different PCB-Layout, to omit led flickering while flashing
Chip settings
ATMEL ATTINY13_20 / ARDUINO
Clock frequency: Default internal clock (9.6MHz / 8 = 1.2MHz)
BOD 4.3V
GCC -Os LTO enabled --> 746 Bytes
Global variables: 7 Bytes
avrdude -c usbasp -p attiny13
Fuse 0x6A 0xF9
Fuse 0x3F
+--------+
[ RST (PB5) |1* 8| (VCC) Power ]
[ Temp (PB3) |2 7| (PB2) RED ]
[ NC (PB4) |3 6| (PB1) GREEN ]
[ Ground (GND) |4 5| (PB0) BLUE ]
+--------+
Fuse Settings
CKSEL1..0: 11 - 128kHz --> HVSP!!
SUT1..0 : 10 - 14CK+64ms
CKDIV8 : 0 - CLK divided by 8 -> 16kHz --> HVSP!! \
NTC table and info
5 volts / 1024 units or, .0049 volts (4.9 mV) per unit
measurement takes place at the engine oil tank drain bolt \
VDO Werte DEPRECATED
55 °C @ 2k Ohm == 0,587V (120EA)
65 °C @ 2k Ohm == 0,423V (87EA)
70 °C @ 2k Ohm == 0,361V (74EA)
75 °C @ 2k Ohm == 0,309V (63EA)
80 °C @ 2k Ohm == 0,265V (55EA)
90 °C @ 2k Ohm == 0,195V (40EA)
100 °C @ 2k Ohm == 0,150V (30EA)
120 °C @ 2k Ohm == 0,089V (18EA)
Koso linear NTC 10k @ 25 °C (guess)
50 °C @ 2k Ohm == 3,41 V (696EA)
55 °C @ 2k Ohm == 3,24 V (662EA)
65 °C @ 2k Ohm == 2,88 V (589EA)
70 °C @ 2k Ohm == 2,72 V (556EA)
75 °C @ 2k Ohm == 2,54 V (518EA)
80 °C @ 2k Ohm == 2,36 V (482EA)
90 °C @ 2k Ohm == 2,06 V (420EA)
100 °C @ 2k Ohm == 1,75 V (359EA)
---------------------------------
110 °C @ 2k Ohm == (300EA) (guess)
the manuel defines the optimal oil temp between 55 - 65 ° C.
this device shows between 50 and 90 °C GREEN
this device shows between 100 and 110 °C RED
above 110 °C the emergency blinking starts \
max value so far: 0x019D = 413 EA ~88°C \
real life hacks
- put the board into a 14mm tube
- seal both ends with a plastic cork and put bee wax on it