This is a recording dual-deploy altimeter for high power model rocketry
with integrated GPS and telemetry link.
-These are photos of our current version,
-which includes an integrated GPS receiver and patch antenna:
+Production units are available from the
+[Garbee and Garbee](http://auric.gag.com) web store.
+
+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>
+
+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:
<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>
* 70cm ham-band transceiver for telemetry downlink
* Barometric pressure sensor good to 45k feet MSL
* 1-axis high-g accelerometer for motor characterization
-* SkyTraq Venus GPS module
+* On-board, integrated GPS receiver
* On-board non-volatile memory for flight data storage
* USB for power, configuration, and data recovery
* Integrated support for LiPo rechargeable batteries
### 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
-* [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
-* 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 [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
* Tools Used
* [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
* [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) temperature sensor instead of using cc1111 on-chip sensor
-* used 1000uF electrolytic capacitor charged to 5V for pyro charges
+* [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) ##
+## [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 ##
## Future Plans ##
-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.
+As of early March 2010, three prototypes of v0.2 exist and have flown with
+great success. We will initiate a production run shortly with the goal of
+making TeleMetrum available in assembled and tested form to others in the
+rocketry hobby in time for the 2010 flying season.
-Because we understand that not everyone uses Linux, we've started discussing
+Because we understand that not everyone uses Linux, we are investigating
the best way to make a cross-platform ground station program for use with
[AltOS](../AltOS), perhaps in Java...
projects / web / altusmetrum / blobdiff