# TeleMetrum
This is a recording dual-deploy altimeter for high power model rocketry
-with integrated telemetry link.
+with integrated GPS and telemetry link.
-<a href="v0.2 SMT side"> <img src="v0.2/cimg5164-cropped.jpg"></a>
-<a href="v0.2 connector side"> <img src="v0.2/cimg5171-cropped.jpg"></a>
-<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>
+These are photos of our current version,
+which includes an integrated GPS receiver and patch antenna:
+
+<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>
+
+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>
## Motivation ##
* Supports dual deployment (can fire 2 ejection charges)
* 70cm ham-band transceiver for telemetry downlink
* Barometric pressure sensor good to 45k feet MSL
-* Temperature sensor
* 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
-* 2.5 x 1 inch board designed to fit inside 29mm airframe coupler 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](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
-* [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM
- * 128k x 8
- * SPI interface
-* Various Sensors
+* 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 passive patch antenna
+ * U.FL connector with 3.3V DC for optional external amplified antenna
+ * 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!
- * [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) temperature sensor
-* Software Features (planned)
+* 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
* Tools Used
* [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
* 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) ##
+### v0.1 Differences ###
+
+* 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
+* [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.
+
+## [Production History](../production) ##
## [Flight Logs](flightlogs) ##
place parts! Without an inspection microscope, loading and testing these
boards might be impossible.
-* 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.
+* 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.
+
+* 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.
## Artifacts ##
* [pcb artwork](v0.1/telemetrum.pcb.pdf)
* [bill of materials](v0.1/telemetrum.bom)
-We have firmware that works well enough that we now routinely allow TeleMetrum
-to control flights by firing ejection charges. We've flown v0.1 boards in
-rockets exceeding 50g acceleration, above Mach 1, and to altitudes greater
-than 12k feet AGL with great results. Keith wrote a ground station program
-called
-ao-view that logs telemetry to disk, displays current and max
-values for key parameters during flight, and even includes voice synthesis
+Our [AltOS](../AltOS) firmware works well enough that we now routinely fly
+TeleMetrum with no backup. Rockets with v0.1 boards have exceeded 50g
+acceleration, been above Mach 1, and reached altitudes greater
+than 12k feet AGL with great results. Keith's ground station program
+called ao-view 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! We have post
flight analysis software that makes it easy to extract data from the board,
analyze it, and even generate KML files for viewing flights in GoogleEarth!
## Future Plans ##
-Work is underway on a second revision of TeleMetrum with the following changes:
-
-* stretch board length by 0.25 inches
-* adjust USB connector position to be flush with edge of board
-* eliminate temperature sensor, since baro sensor is already compensated and there's a sensor on the cc1111
-* eliminate serial port connector
-* integrate SkyTraq Venus GPS receiver and patch antenna on-board
-* change debug connector to 4 pin Tyco MicroMaTch
-* add 8 pin Tyco MicroMaTch connector for companion board interface
-* use v_lipo as pyro power, eliminating the huge 1000uF capacitor and instead
- adding ballast capacitance on the 3.3V rail to prevent brownouts
-* move all connectors, beeper, and GPS patch antenna to the "other side" of the board from the surface mount parts
-* add a rectangle of silk screen material for improved serial number labeling
-
-As of early December 2009, the layout work for v0.2 is done and we're busy
-verifying it and deciding exactly how we're going to build them. We hope to
-have first prototypes to test in time to show the new version at LCA in late
-January 2010. If it works out as well as we hope, v0.2 may be made available
-in assembled and tested form to others in the rocketry hobby who have
-expressed interest sometime in 2010.
+As of early February 2010, three prototypes of v0.2 are done and working on
+the bench. We hope to flight test them shortly, then arrange a production
+run in time to make TeleMetrum available in assembled and tested form to
+others in the rocketry hobby who have expressed interest in time for the
+2010 flying season.
+
+Because we understand that not everyone uses Linux, we've started discussing
+the best way to make a cross-platform ground station program for use with
+[AltOS](../AltOS), perhaps in Java...
projects / web / altusmetrum / blobdiff