From 7164193af971608b879a25af640e7a0f8818077a Mon Sep 17 00:00:00 2001 From: df8oe Date: Thu, 15 Jun 2017 14:33:32 +0200 Subject: [PATCH] beginning of reverse engineering of temperature and humidity sensors --- docs/infos_for_sensors.txt | 73 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 docs/infos_for_sensors.txt diff --git a/docs/infos_for_sensors.txt b/docs/infos_for_sensors.txt new file mode 100644 index 0000000..863ee67 --- /dev/null +++ b/docs/infos_for_sensors.txt @@ -0,0 +1,73 @@ +DF8OEs investigations about sensor access +------------------------------------------ + + + +Temperature and humidity sensor directly goes to STM. There is no interface +chip to handle them - all is done by software. + + + +Pinout of sensor boom: +---------------------- +1 - GND +2 - temperature sensor (1) +3 - GND +4 - +5 - GND +6 - +7 - GND +8 - +9 - +10 - GND +11 - +12 - GND +13 - temperature sensor (2) +14 - GND +15 - GND +16 - GND +17 - GND +18 - GND +19 - GND +20 - GND + +Counted from left to right if you position flexsensor in front of you, pins near +to you, sensor away from you, copper upside + + + +All connections leading to sensor boom do have corresponding test points on PCB: +-------------------------------------------------------------------------------- +Position PCB in front of you, flatconnector upside, sensor boom showing away from +you, TX antenna leading to you. I draw connector as a row of "+++". Testpoints are +small round copper isles (numbers correspond to sensor boom, G == GND, ? == unknown): + + + + + 11 + +++++++++++++++++++++++ + + G 4 + + + 8 6 2 + + + 13 ? 9 + + +Investigations about temperature sensor: +---------------------------------------- +Temperatrue sensor is resistance-based. If you insert a resistor between +pin2 and pin13 of flatconnector, the following telemetry is transmitted: + +330R --> -168° +560R --> -113° +820R --> -52° +1K --> -4.1° +1.5K --> 121° +2.2K --> 319° + + +2 be continued \ No newline at end of file