# TeleMetrum
-This is a recording altimeter for high power model rocketry with integrated
-telemetry link.
+This is a recording dual-deploy altimeter for high power model rocketry
+with integrated telemetry link.
+
+<a href="loadedpair.jpg"> <img src="loadedpair-thumb.jpg"></a>
+<a href="rawfront.jpg"> <img src="rawfront-thumb.jpg"></a>
+<a href="rawback.jpg"> <img src="rawback-thumb.jpg"></a>
## Motivation ##
* Recording altimeter for model rocketry
* Supports dual deployment (can fire 2 ejection charges)
* 70cm ham-band transceiver for telemetry downlink
-* Primary operations based on pressure sensor
+* Barometric pressure sensor good to 45k feet MSL
* Temperature sensor
* 1-axis high-g accelerometer for motor characterization
* On-board non-volatile memory for flight data storage
* Serial port for attachment of GPS module
* USB for power, configuration, and data recovery
* Integrated support for LiPo rechargeable batteries
-* Designed to fit 29mm airframe tube
+* 2.5 x 1 inch board designed to fit inside 29mm airframe coupler tube
### Developer View ###
-* TI CC1111F32 Low Power RF System-on-Chip
+* [TI CC1111F32](http://focus.ti.com/docs/prod/folders/print/cc1111f32.html) Low Power RF System-on-Chip
* Sub-1Ghz transceiver
* 8051 MCU
* 32k Flash
* 4k RAM
* USB 2.0
- * analog, digital, and serial I/O
-* Microchip 25LC1024 CMOS serial EEPROM
+ * 6 12-bit analog inputs (11 bits with single-ended sensors)
+ * 2 channels of serial I/O
+ * digital I/O
+* [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM
* 128k x 8
* SPI interface
* Various Sensors
- * Freescale MP3H6115A pressure sensor
- * Freescale MMA2202EG 50g accelerometer. Can use 40-200g variants!
- * Microchip MCP9700A temperature sensor
+ * [Freescale MP3H6115A](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MP3H6115A6U) pressure sensor
+ * [Freescale MMA2202EG](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MMA2202EG) 50g accelerometer. Can use 40-200g variants!
+ * [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) temperature sensor
* Software Features (planned)
* Written mostly in C with some 8051 assembler
* Runs from on-chip flash, uses on-chip RAM, stores flight data to
serial EEPROM chip
* USB serial emulation for "console" interface
- * USB mass storate emulation for data recovery
- * Uses the SDCC compiler and FreeRTOS
+* Tools Used
+ * [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
+ * [SDCC](http://sdcc.sourceforge.net/) compiler and source debugger
* Licenses
- * The hardware is licensed under the TAPR OHL
- * The software is licensed GPL version 2
+ * The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
+ * The software is licensed [GPL version 2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html)
+
+## [Production History](production) ##
+
+## [Flight Logs](flightlogs) ##
## Problems ##
-* The CC1111F32 is a 36-pin QFN package, which necessitates reflow soldering.
+* The CC1111F32 is a 36-pin QFN package, which necessitates reflow
+ soldering. Since we needed to reflow solder anyway, and because TI used
+ them in their reference design, we went a little crazy and used 0402
+ passive parts everywhere. That means working under a microscope to
+ place parts! Without an inspection microscope, loading and testing these
+ boards might be impossible.
-* Since we needed to reflow solder anyway, and because TI used them in their
- reference design, we went a little crazy and used 0402 passive parts
- everywhere. That means working under a microscope to place parts!
+* The v0.1 artwork has the USB connector footprint placed wrong, so that the
+ connector hangs out over the edge of the board instead of being flush with
+ the edge.
+
+* The v0.1 artwork has two issues that require cuts and jumps. The first is
+ that we need chip select on the SPI memory. To fix that, we give up the
+ ability to put the accelerometer into self-test mode and use that GPIO line
+ to pull chip select on the memory. The second is that the igniter sense
+ circuits each need a second resistor to complete the voltage divider so our
+ 3.3V CPU ADC can read the 5V ejection voltage. This is fixed by changing
+ two resistor values, and tacking two additional resistors onto the board
+ with jumpers to ground.
## Artifacts ##
The hardware design current gEDA files are available from
-[git.gag.com](http://git.gag.com).
+[git.gag.com](http://git.gag.com). The 'fab' tag on the master branch reflects
+the artwork as sent out for PCB fab. The 'loaded' tag on the master branch
+indicates the parts Bdale loads for a functional board, but the schematic
+does not reflect the cuts and jumps or added resistors. The 'nextcut' branch
+is work towards our next PCB revision. The 'ground' branch has a cut-down
+schematic used to generate the BOM for partially loading boards to use in
+the matching TeleTerra ground station design.
+
+Keith has working data collection firmware, however the firmware is under a
+massive, rapid rewrite to eliminate FreeRTOS which is much more generalized
+and capable than we need... and consuming more system resources than we
+can tolerate. As soon as we're over this transition, the sourcecode to the
+firmware and related tools will also be made available.
-As of 1 January 2009, the parts and stencil for the v0.1 have arrived, and
-we're waiting for the raw PC boards! Stay tuned for updates, and note that
-Bdale will be giving an update in his session at Linux Conference Australia
-in late January...
+As of 11 April 2009, the first two boards are fully checked out, we have some
+initial firmware capable of data logging ready, and as soon as we get a good
+day to fly we hope to log our first flight data!
projects / web / altusmetrum / blobdiff