LED-thermometer/README.md
2022-12-01 06:46:57 +01:00

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 Need to be compiled with -O3 Flag INFO: ledcolor==3 block is obsolete.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

  1. bug fix where Blinking RED would not change led_color back --> global/local definiton
  2. 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