# 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 GPS and telemetry link.
+
+Production units are available from the
+[Garbee and Garbee](http://auric.gag.com) web
+store. TeleMetrum starter kits are also now available from
+[Apogee Components](http://www.apogeerockets.com/Altus_Metrum_GPS.asp).
+
+For the latest TeleMetrum firmware and related ground station software, please
+visit the [AltOS](../AltOS) page on this site.
+
+These are photos of our current production version, which includes an
+integrated GPS receiver with active patch antenna:
+
+<a href="v1.0/cimg5972-crop.jpg"> <img src="v1.0/cimg5972-thumb.jpg"></a>
+<a href="v1.0/cimg5974-crop.jpg"> <img src="v1.0/cimg5974-thumb.jpg"></a>
## Motivation ##
They use a PIC processor and a TI CC1050 transmitter chip, and
operate in the ham radio 70cm band.
-One weekend while attending a conference together, We got to wondering if
+One weekend while attending a conference together, we got to wondering if
we couldn't adapt one to use as a downlink for the
[AltusMetrum](../AltusMetrum/) altimeter board in addition to direction
finding after flight. That caused us to start thinking about other things
using a different part in the same TI series, that integrated a transceiver
and CPU on the same chip.
It didn't take us long to realize that with such a part we could combine and
-simplify things by building a new altimeter with integrated RF link!
+simplify things by building a new altimeter with integrated RF link! And
+after gaining some experience in 2009 with a first version, we realized we
+always want GPS on board, which lead to our current second generation boards.
## Features ##
* 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
-* Temperature sensor
+* Barometric pressure sensor good to 45k feet MSL
* 1-axis high-g accelerometer for motor characterization
+* On-board, integrated GPS receiver
* 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
+* Uses LiPo to fire e-matches, optional support for separate pyro battery
+* 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube
### Developer View ###
-* TI CC1111F32 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
- * 128k x 8
- * SPI interface
-* Various Sensors
- * Freescale MP3H6115A pressure sensor
- * Freescale MMA2202 50g accelerometer
- * Microchip MCP9700A temperature sensor
+* Hardware Features
+ * [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
+ * 6 12-bit analog inputs (11 bits with single-ended sensors)
+ * 2 channels of serial I/O
+ * digital I/O
+ * [Atmel AT45DB081D](http://www.atmel.com/dyn/products/product_card.asp?part_id=3819) DataFlash memory
+ * 1M x 8
+ * 256 byte page size
+ * SPI interface
+ * other parts in this Atmel DataFlash series can optionally be used
+ * [SkyTraq](http://www.skytraq.com.tw/) Venus634FLPx GPS receiver
+ * on-board [Taoglas AP.17A.01](http://www.taoglas.com/antennas/GPS_Antennas/Internal_GPS_-_Active_Patch_Modules/)
+ single-stage active patch antenna
+ * U.FL connector with 3.3V DC can be re-purposed for optional external amplified antennas
+ * async serial interface
+ * [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!
* Software Features
* Written mostly in C with some 8051 assembler
* Runs from on-chip flash, uses on-chip RAM, stores flight data to
- serial EEPROM chip
+ serial DataFlash chip
* USB serial emulation for "console" interface
- * 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
-
-## Problems ##
+ * 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)
-* The CC1111F32 is a 36-pin QFN package, which necessitates reflow soldering.
+## [Production History](../production) ##
-* 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!
+## [Flight Logs](flightlogs) ##
## Artifacts ##
+There is a single manual for TeleMetrum and all other Altus Metrum products,
+which is available in [html](../AltOS/doc/altusmetrum.html) and
+[pdf](../AltOS/doc/altusmetrum.pdf) formats.
+
The hardware design current gEDA files are available from
-[git.gag.com](http://git.gag.com).
+[git.gag.com](http://git.gag.com) in the project
+[hw/telemetrum](http://git.gag.com/?p=hw/telemetrum;a=summary).
+
+Work on the next version proceeds on the master branch, with occasional
+temporary branches created when Bdale is making some major / speculative
+change. The 'v0.2' and 'v0.1' branches document what we're actually flying
+right now on the two respective PCB revisions. The 'ground' branch has a
+cut-down schematic used to generate the BOM for partially loading v0.1 boards
+to used on the ground. We call the on-the-ground
+version '[TeleDongle](../TeleDongle)', and newer versions have their own PCB
+design.
+
+For those who don't have ready access to the gEDA suite, here are pdf snapshots
+of the files for Production PCB version 1.0 in more easily readable form.
+
+* [schematic](v1.0/telemetrum.pdf)
+* [pcb artwork](v1.0/telemetrum.pcb.pdf)
+* [bill of materials](v1.0/partslist.csv)
+
+We consider our [AltOS](../AltOS) firmware completely reliable, and routinely
+fly TeleMetrum with no backup. Rockets with TeleMetrum boards
+have exceeded 50g acceleration, been well above Mach 1, and reached altitudes
+greater than 25k feet AGL with great results. Keith's second generation
+ground station program called altosui works on Windows, Mac, and Linux systems
+and logs telemetry to disk, displays current and max values for key parameters
+during flight, and even includes voice synthesis during the flight so that
+our eyes can stay on the rockets! After flight, altosui can extract the
+complete flight log from TeleMetrum, can display plots of the data from either
+the telemetry received by radio or the onboard flight log, can output a kml
+file for use with [Google Earth](http://earth.google.com), and can also
+output all the flight data as a csv file for easy import to spreadsheet
+programs or other analysis tools allowing you to perform whatever
+custom analysis you can envision! More details on the software,
+including full source code and pre-built packages
+can be found on the [AltOS](../AltOS) page on this site.
+
+## Future Plans ##
+
+TeleMetrum v1.0 meets all of our expectations. We anticipate another
+production run of boards soon, which will include minor design tweeks mostly
+to work around component availability issues.
+
+## Problems ##
+
+* 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.
+
+* The addition of on-board GPS in v0.2 means that the total power consumption
+ can exceed the rate at which we draw power from the USB interface,
+ particularly when the GPS is in cold start mode. This means a battery must
+ be attached during operation, and also that the battery will only charge
+ effectively from USB when the board is turned off.
+
+## History ##
+
+### v0.2 ###
+
+These are photos of our second version, which included the integrated Venus
+GPS receiver, but with a passive patch antenna that turned out to have
+disappointing performance due to our many PCB geometry constraints. It also
+used a voltage regulator with less capacity which we felt was marginal for
+supporting the companion boards we have planned:
+
+<a href="v0.2/cimg5164-cropped.jpg"> <img src="v0.2/cimg5164-thumb.jpg"></a>
+<a href="v0.2/cimg5171-cropped.jpg"> <img src="v0.2/cimg5171-thumb.jpg"></a>
+
+Other than cleaning up the silkscreen, the differences between v0.2 and our
+current v1.0 boards were really quite small:
+
+* 100ma LDO regulator instead of the current 150ma part
+* no C38 footprint
+* different value for C36 reset capacitor
+
+The schematics and PCB artwork for this version are on the v0.2 branch in
+our git repository, here are pdf copies for easy reference:
+
+ * [schematic](v0.2/telemetrum.pdf)
+ * [pcb artwork](v0.2/telemetrum.pcb.pdf)
+ * [bill of materials](v0.2/partslist.csv)
+
+### v0.1 ###
+
+And this is a photo of our original board with serial port for off-board GPS,
+without the big off-board 1000uF cap from the original ejection circuit:
+
+<a href="v0.1/loadedpair.jpg"> <img src="v0.1/loadedpair-thumb.jpg"></a>
+
+The differences between v0.1 and later boards were substantial:
+
+* 2.5 x 1 inch board with all parts mounted on one side
+* 4-pin PicoBlade serial port connector for attachment of external GPS module
+* USB connector projected approximately 3mm over the edge of the board
+* Debug connector used 4 IC socket pins on 100 mil centers
+* no companion board interface
+* 50ma LDO regulator on early boards, later boards used a 100ma part
+* [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM instead of DataFlash
+ * 128k x 8
+ * SPI interface
+* [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) discrete temperature sensor
+* used 1000uF electrolytic capacitor charged to 5V for pyro supply
+* two LEDs instead of one attached to CPU
+
+The elimination of the discrete temperature sensor and second LED were
+necessary to support the companion board interface added in v0.2.
+
+The v0.1 artwork had three issues, two of which required physical rework
+on each board. All of these issues were fixed in v0.2.
+
+* The USB connector footprint was placed wrong, so that the
+ connector hung out over the edge of the board instead of being
+ flush.
+* We needed chip select on the SPI memory. To fix that, we gave up the
+ ability to put the accelerometer into self-test mode and used that
+ GPIO line to pull chip select on the memory, which required two
+ cuts and two jumpers.
+* The igniter sense circuits each needed a second resistor to
+ complete the voltage divider so our 3.3V CPU ADC could read the
+ 5V ejection voltage. This was fixed by changing two resistor
+ values, and tacking two additional resistors onto the board
+ with jumpers to ground.
+
+The schematics and PCB artwork for this version as of the working-v0.1 tag
+are available here are pdf copies for easy reference:
-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...
+ * [schematic](v0.1/telemetrum.pdf)
+ * [pcb artwork](v0.1/telemetrum.pcb.pdf)
+ * [bill of materials](v0.1/telemetrum.bom)
projects / web / altusmetrum / blobdiff