X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=TeleMetrum%2Findex.mdwn;h=57c06c2d960eb8044d50ad32f483b77d330f4636;hb=dd7ee4ce9cbada2ceb95dd167b1e89bca3be6355;hp=6ebc768868baa191518043a2e3b63089db0c2fb3;hpb=6da0c7bbadd549fad309aceefa15bfad52cdbbef;p=web%2Faltusmetrum
diff --git a/TeleMetrum/index.mdwn b/TeleMetrum/index.mdwn
index 6ebc768..57c06c2 100644
--- a/TeleMetrum/index.mdwn
+++ b/TeleMetrum/index.mdwn
@@ -1,32 +1,21 @@
# TeleMetrum
This is a recording dual-deploy altimeter for high power model rocketry
-with integrated telemetry link.
-
- 
- 
- 
-
-## Motivation ##
-
-Bdale and Keith both own
-[BeeLine](http://www.bigredbee.com/BeeLine.htm)
-trackers from
-[Big Red Bee](http://www.bigredbee.com), and are pretty happy with them.
-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
-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
-in the design we might want to tweak, and before long we were working on the
-design of a new tracker board derived from the BeeLine design.
-Another friend at the same conference showed us a board he was working on
-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!
+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:
+
+ 
+ 
## Features ##
@@ -35,45 +24,101 @@ simplify things by building a new altimeter with integrated RF link!
* 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
-* 2.5 x 1 inch board designed to fit inside 29mm airframe coupler tube
+* Uses LiPo to fire e-matches, can be factory modified to support 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
- * analog, digital, and serial 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
+ * [Winbond W25Q16](http://www.winbond.com/NR/exeres/A3D21C82-A0B6-4586-A770-2F0883A805FF.htm) serial flash memory
+ * 2M x 8
+ * SPI interface
+ * [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!
- * [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
- * USB mass storage emulation for data recovery
* Tools Used
* [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
* [SDCC](http://sdcc.sourceforge.net/) compiler and source debugger
- * [FreeRTOS](http://www.freertos.org/) kernel
* Licenses
* 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) ##
+
+## 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) 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. Branched with names like 'v0.2' document what we're actually flying
+on the 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](v1.1/telemetrum.pdf)
+* [pcb artwork](v1.1/telemetrum.pcb.pdf)
+* [bill of materials](v1.1/partslist.csv)
+
+Rockets we know of flying 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, includes voice synthesis during the flight so that
+our eyes can stay on the rockets, and even includes live display of rocket
+position over moving maps! 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 v1.1 meets all of our expectations, except for one mis-placed
+trace also present in v1.0. The error makes use of a separate pyro battery
+less trivial than intended. We'll fix that for a future production run.
+
## Problems ##
* The CC1111F32 is a 36-pin QFN package, which necessitates reflow
@@ -83,32 +128,108 @@ simplify things by building a new altimeter with integrated RF link!
place parts! Without an inspection microscope, loading and testing these
boards might be impossible.
-* 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
+* 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 ##
+
+### v1.0 ###
+
+These are photos of our third version, which was the basis of our first
+production build. These were sold between April and December 2010, and
+performed very well.
+
+ 
+ 
+
+The differences between v1.0 and v1.1 were small:
+
+* different flash memory part due to supplier availability problems
+* changed the GPS antenna footprint to eliminate the large through-hole
+ originally intended for use with a passive patch
+* irq line eliminated from the companion port
+* an additional resistor divider added to allow sampling the 5V supply
+
+The schematics and PCB artwork for this version are on the v1.0 branch in
+our git repository, here are pdf copies for easy reference:
+
+* [schematic](v1.0/telemetrum.pdf)
+* [pcb artwork](v1.0/telemetrum.pcb.pdf)
+* [bill of materials](v1.0/partslist.csv)
+
+
+### 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:
+
+ 
+ 
+
+Other than cleaning up the silkscreen, the differences between v0.2 and
+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:
+
+ 
+
+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.
-## Artifacts ##
+The schematics and PCB artwork for this version as of the working-v0.1 tag
+are available here are pdf copies for easy reference:
-The hardware design current gEDA files are available from
-[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 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!
+ * [schematic](v0.1/telemetrum.pdf)
+ * [pcb artwork](v0.1/telemetrum.pcb.pdf)
+ * [bill of materials](v0.1/telemetrum.bom)
- 
-
-## Motivation ##
-
-Bdale and Keith both own
-[BeeLine](http://www.bigredbee.com/BeeLine.htm)
-trackers from
-[Big Red Bee](http://www.bigredbee.com), and are pretty happy with them.
-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
-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
-in the design we might want to tweak, and before long we were working on the
-design of a new tracker board derived from the BeeLine design.
-Another friend at the same conference showed us a board he was working on
-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!
+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:
+
+ 
+ 
## Features ##
@@ -35,45 +24,101 @@ simplify things by building a new altimeter with integrated RF link!
* 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
-* 2.5 x 1 inch board designed to fit inside 29mm airframe coupler tube
+* Uses LiPo to fire e-matches, can be factory modified to support 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
- * analog, digital, and serial 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
+ * [Winbond W25Q16](http://www.winbond.com/NR/exeres/A3D21C82-A0B6-4586-A770-2F0883A805FF.htm) serial flash memory
+ * 2M x 8
+ * SPI interface
+ * [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!
- * [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
- * USB mass storage emulation for data recovery
* Tools Used
* [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
* [SDCC](http://sdcc.sourceforge.net/) compiler and source debugger
- * [FreeRTOS](http://www.freertos.org/) kernel
* Licenses
* 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) ##
+
+## 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) 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. Branched with names like 'v0.2' document what we're actually flying
+on the 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](v1.1/telemetrum.pdf)
+* [pcb artwork](v1.1/telemetrum.pcb.pdf)
+* [bill of materials](v1.1/partslist.csv)
+
+Rockets we know of flying 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, includes voice synthesis during the flight so that
+our eyes can stay on the rockets, and even includes live display of rocket
+position over moving maps! 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 v1.1 meets all of our expectations, except for one mis-placed
+trace also present in v1.0. The error makes use of a separate pyro battery
+less trivial than intended. We'll fix that for a future production run.
+
## Problems ##
* The CC1111F32 is a 36-pin QFN package, which necessitates reflow
@@ -83,32 +128,108 @@ simplify things by building a new altimeter with integrated RF link!
place parts! Without an inspection microscope, loading and testing these
boards might be impossible.
-* 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
+* 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 ##
+
+### v1.0 ###
+
+These are photos of our third version, which was the basis of our first
+production build. These were sold between April and December 2010, and
+performed very well.
+
+ 
+ 
+
+The differences between v1.0 and v1.1 were small:
+
+* different flash memory part due to supplier availability problems
+* changed the GPS antenna footprint to eliminate the large through-hole
+ originally intended for use with a passive patch
+* irq line eliminated from the companion port
+* an additional resistor divider added to allow sampling the 5V supply
+
+The schematics and PCB artwork for this version are on the v1.0 branch in
+our git repository, here are pdf copies for easy reference:
+
+* [schematic](v1.0/telemetrum.pdf)
+* [pcb artwork](v1.0/telemetrum.pcb.pdf)
+* [bill of materials](v1.0/partslist.csv)
+
+
+### 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:
+
+ 
+ 
+
+Other than cleaning up the silkscreen, the differences between v0.2 and
+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:
+
+ 
+
+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.
-## Artifacts ##
+The schematics and PCB artwork for this version as of the working-v0.1 tag
+are available here are pdf copies for easy reference:
-The hardware design current gEDA files are available from
-[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 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!
+ * [schematic](v0.1/telemetrum.pdf)
+ * [pcb artwork](v0.1/telemetrum.pcb.pdf)
+ * [bill of materials](v0.1/telemetrum.bom)