From 166b18ad419583cc0015650cc407d79be4471ec4 Mon Sep 17 00:00:00 2001 From: Christian Pointner Date: Thu, 19 Dec 2013 23:43:08 +0000 Subject: added some documentation on MCUs git-svn-id: https://svn.spreadspace.org/mur.sat@859 7de4ea59-55d0-425e-a1af-a3118ea81d4c --- doc/MCUs | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 doc/MCUs diff --git a/doc/MCUs b/doc/MCUs new file mode 100644 index 0000000..6b2afc6 --- /dev/null +++ b/doc/MCUs @@ -0,0 +1,114 @@ +List of all MCUs and their purpose +=================================== + + MPU - Main Processing Unit + ---------------------------- + This is the most powerful processor aboard and runs the satellites main + operating system which is based on ChibiOS. The MPU runs the payload + applications and maintains the high level communication channel to the + groundstation network. + + Tasks: + - store collected data -> SDCard (min. 4 GB) + - monitor SOL (rotations, camera) -> SDCard + - takes pictures using camera -> SDCard + check SOL if picture is worth a try + evaluate pictures if it is worth transferring + - record audio (using IDM) -> SDCard + encode raw audio (from IDM) to FLAC + evaluate audio if it is worth transferring + - control LIS (LED in space) + - monitor ANC for pressed button -> Beacon!! + - communicate with ground stations (using COMM) + + + IDM - Impact detection module + ------------------------------- + This is basically a very low power soundcard which watches the output of + a small piezo microphone and starts recording when a signal is detected. + It then wakes the MPU for further processing. + Optionally the IDM may also 'play' sounds from MPU using yet another piezo. + This can be used as a payload application or to test the signal detection. + + Tasks: + - wait for 'impacts' aka signals form microphone + - ater 'noise' start recording and wake up MPU + - when internal ring buffer is full stop recording + - MPU may start downloading the audio data which prevents + ring buffer from overfilling -> endless recording + - recording may be triggered by MPU as well + - MPU may send audio data which should be played using a + small piezo (optional) + + + IHU - internal houskeeping unit + --------------------------------- + This processor runs the low level operating system which maintains power + levels, reboots MPU and other subsystems on error and controls the system + clock (RTC). + + Tasks: + - maintain vital-power (turn of main power to prevent power outages) + - monitor solar energy levels + - battery management (using BAT) + - power path control (using BAT) + - temperature management (sensors and heating) + - MPU overwatch (reset on error) + - CTR overwatch (reset on error) + - report power states and environment to MPU and CTR + - control RTC and report system time to MPU and CTR + - enforce radio silence + + + BAT - battery management + -------------------------- + A simple battery monitoring and control device which reports all measured + values to IHU and serves as a persistent power path controller (states + should be maintained even after total power loss) + + Tasks: + - periodically measure currents, voltates and tempertatures of all battery + packs and report them to IHU + - mitigate short circuit conditions by disabling the charge or discharge + channels for all or some battery packs + - report fault conditions (short circuit, defective batteries, etc... to IHU + + + CTR - command transmit/receive + -------------------------------- + This MCU maintains the low level communication (TTX and CRX). + TTX is a simple CW beacon containing telemetry information and a sequence number + CRX is the emergency command receiver which may be used to invoke emergency + commands such as 'radio silence' or 'reset'. + + Tasks: + - IHU overwatch (reset on error??) + - listen for incoming CRX commands + - send out telemetry beacons (TTX) + + + COMM - communications + ----------------------- + This processor controls the 2m and 70cm transceivers. There are two radios. + Each consist of one COMM processor, one 2m transceiver and on 70cm transcevier. + A static network of gates takes care of assigning radios to MPU and CRX. + + Tasks: + - initialize and control the 2m and 70cm transceivers + - send out data frames when requeseted by MPU or CTR + - wait for incoming data frames when requested by MPU or CTR + + + +Flash/Update Mechanism +======================= + All MCUs inside mur.sat should be updateable through a single + USB Port (connected to MPU). + + MCUs to update: + - MPU (STM32F103/STM32F405) USB -> PC (Entry Point) + - IDM (PIC 16F1847) SPI -> MPU + - IHU (PIC 16F887) RS232 -> MPU + - BAT (PIC 16F887) SPI -> IHU + - CTR (PIC 16F887) SPI -> IHU + - COMM (AtTiny??) x2 RS232 -> MPU -- cgit v1.2.3