3 This is a recording dual-deploy altimeter for high power model rocketry
4 with integrated GPS and telemetry link.
6 Production units are available from the
7 [Garbee and Garbee](http://auric.gag.com) web
8 store. [TeleMetrum](TeleMetrum/) starter kits are also now available from
9 [Apogee Components](http://www.apogeerockets.com/Altus_Metrum_GPS.asp).
11 These are photos of our current production version, which includes an
12 integrated GPS receiver with active patch antenna:
14 <a href="v1.0/cimg5972-crop.jpg"> <img src="v1.0/cimg5972-thumb.jpg"></a>
15 <a href="v1.0/cimg5974-crop.jpg"> <img src="v1.0/cimg5974-thumb.jpg"></a>
19 Bdale and Keith both own
20 [BeeLine](http://www.bigredbee.com/BeeLine.htm)
22 [Big Red Bee](http://www.bigredbee.com), and are pretty happy with them.
23 They use a PIC processor and a TI CC1050 transmitter chip, and
24 operate in the ham radio 70cm band.
26 One weekend while attending a conference together, we got to wondering if
27 we couldn't adapt one to use as a downlink for the
28 [AltusMetrum](../AltusMetrum/) altimeter board in addition to direction
29 finding after flight. That caused us to start thinking about other things
30 in the design we might want to tweak, and before long we were working on the
31 design of a new tracker board derived from the BeeLine design.
32 Another friend at the same conference showed us a board he was working on
33 using a different part in the same TI series, that integrated a transceiver
34 and CPU on the same chip.
35 It didn't take us long to realize that with such a part we could combine and
36 simplify things by building a new altimeter with integrated RF link! And
37 after gaining some experience in 2009 with a first version, we realized we
38 always want GPS on board, which lead to our current second generation boards.
44 * Recording altimeter for model rocketry
45 * Supports dual deployment (can fire 2 ejection charges)
46 * 70cm ham-band transceiver for telemetry downlink
47 * Barometric pressure sensor good to 45k feet MSL
48 * 1-axis high-g accelerometer for motor characterization
49 * On-board, integrated GPS receiver
50 * On-board non-volatile memory for flight data storage
51 * USB for power, configuration, and data recovery
52 * Integrated support for LiPo rechargeable batteries
53 * Uses LiPo to fire e-matches, optional support for separate pyro battery
54 * 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube
56 ### Developer View ###
59 * [TI CC1111F32](http://focus.ti.com/docs/prod/folders/print/cc1111f32.html) Low Power RF System-on-Chip
60 * Sub-1Ghz transceiver
65 * 6 12-bit analog inputs (11 bits with single-ended sensors)
66 * 2 channels of serial I/O
68 * [Atmel AT45DB081D](http://www.atmel.com/dyn/products/product_card.asp?part_id=3819) DataFlash memory
72 * other parts in this Atmel DataFlash series can optionally be used
73 * [SkyTraq](http://www.skytraq.com.tw/) Venus634FLPx GPS receiver
74 * on-board [Taoglas AP.17A.01](http://www.taoglas.com/antennas/GPS_Antennas/Internal_GPS_-_Active_Patch_Modules/)
75 single-stage active patch antenna
76 * U.FL connector with 3.3V DC can be re-purposed for optional external amplified antennas
77 * async serial interface
78 * [Freescale MP3H6115A](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MP3H6115A6U) pressure sensor
79 * [Freescale MMA2202EG](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MMA2202EG) 50g accelerometer. Can use 40-200g variants!
81 * Written mostly in C with some 8051 assembler
82 * Runs from on-chip flash, uses on-chip RAM, stores flight data to
84 * USB serial emulation for "console" interface
86 * [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
87 * [SDCC](http://sdcc.sourceforge.net/) compiler and source debugger
89 * The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
90 * The software is licensed [GPL version 2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html)
92 ## [Production History](../production) ##
94 ## [Flight Logs](flightlogs) ##
98 The user manual for TeleMetrum is available in
99 [html](doc/telemetrum-doc.html) and [pdf](doc/telemetrum-doc.pdf)
102 The hardware design current gEDA files are available from
103 [git.gag.com](http://git.gag.com) in the project
104 [hw/telemetrum](http://git.gag.com/?p=hw/telemetrum;a=summary).
106 Work on the next version proceeds on the master branch, with occasional
107 temporary branches created when Bdale is making some major / speculative
108 change. The 'v0.2' and 'v0.1' branches document what we're actually flying
109 right now on the two respective PCB revisions. The 'ground' branch has a
110 cut-down schematic used to generate the BOM for partially loading v0.1 boards
111 to used on the ground. We call the on-the-ground version 'TeleDongle'.
113 For those who don't have ready access to the gEDA suite, here are pdf snapshots
114 of the files for Production PCB version 1.0 in more easily readable form.
116 * [schematic](v1.0/telemetrum.pdf)
117 * [pcb artwork](v1.0/telemetrum.pcb.pdf)
118 * [bill of materials](v1.0/partslist.csv)
120 Our [AltOS](../AltOS) firmware works well enough that we now routinely fly
121 TeleMetrum with no backup. Rockets with v0.1 boards have exceeded 50g
122 acceleration, been above Mach 1, and reached altitudes greater
123 than 12k feet AGL with great results. Keith's ground station program
124 called ao-view logs telemetry to disk, displays current and max values for
125 key parameters during flight, and even includes voice synthesis
126 during the flight so that our eyes can stay on the rockets! We have post
127 flight analysis software that makes it easy to extract data from the board,
128 analyze it, and even generate KML files for viewing flights in GoogleEarth!
129 More details on the software, including full source code and pre-built packages
130 can be found on the [AltOS](../AltOS) page on this site.
134 As of May 2010, version v1.0 is available for sale from the
135 [Garbee and Garbee](http://auric.gag.com) web store.
137 Because we understand that not everyone uses Linux, development of a new
138 cross-platform ground station program written in Java is underway for use with
143 * The CC1111F32 is a 36-pin QFN package, which necessitates reflow
144 soldering. Since we needed to reflow solder anyway, and because TI used
145 them in their reference design, we went a little crazy and used 0402
146 passive parts everywhere. That means working under a microscope to
147 place parts! Without an inspection microscope, loading and testing these
148 boards might be impossible.
150 * The addition of on-board GPS in v0.2 means that the total power consumption
151 can exceed the rate at which we draw power from the USB interface,
152 particularly when the GPS is in cold start mode. This means a battery must
153 be attached during operation, and also that the battery will only charge
154 effectively from USB when the board is turned off.
160 These are photos of our second version, which included the integrated Venus
161 GPS receiver, but with a passive patch antenna that turned out to have
162 disappointing performance due to our many PCB geometry constraints. It also
163 used a voltage regulator with less capacity which we felt was marginal for
164 supporting the companion boards we have planned:
166 <a href="v0.2/cimg5164-cropped.jpg"> <img src="v0.2/cimg5164-thumb.jpg"></a>
167 <a href="v0.2/cimg5171-cropped.jpg"> <img src="v0.2/cimg5171-thumb.jpg"></a>
169 Other than cleaning up the silkscreen, the differences between v0.2 and our
170 current v1.0 boards were really quite small:
172 * 100ma LDO regulator instead of the current 150ma part
174 * different value for C36 reset capacitor
176 The schematics and PCB artwork for this version are on the v0.2 branch in
177 our git repository, here are pdf copies for easy reference:
179 * [schematic](v0.2/telemetrum.pdf)
180 * [pcb artwork](v0.2/telemetrum.pcb.pdf)
181 * [bill of materials](v0.2/partslist.csv)
185 And this is a photo of our original board with serial port for off-board GPS,
186 without the big off-board 1000uF cap from the original ejection circuit:
188 <a href="v0.1/loadedpair.jpg"> <img src="v0.1/loadedpair-thumb.jpg"></a>
190 The differences between v0.1 and later boards were substantial:
192 * 2.5 x 1 inch board with all parts mounted on one side
193 * 4-pin PicoBlade serial port connector for attachment of external GPS module
194 * USB connector projected approximately 3mm over the edge of the board
195 * Debug connector used 4 IC socket pins on 100 mil centers
196 * no companion board interface
197 * 50ma LDO regulator on early boards, later boards used a 100ma part
198 * [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM instead of DataFlash
201 * [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) discrete temperature sensor
202 * used 1000uF electrolytic capacitor charged to 5V for pyro supply
203 * two LEDs instead of one attached to CPU
205 The elimination of the discrete temperature sensor and second LED were
206 necessary to support the companion board interface added in v0.2.
208 The v0.1 artwork had three issues, two of which required physical rework
209 on each board. All of these issues were fixed in v0.2.
211 * The USB connector footprint was placed wrong, so that the
212 connector hung out over the edge of the board instead of being
214 * We needed chip select on the SPI memory. To fix that, we gave up the
215 ability to put the accelerometer into self-test mode and used that
216 GPIO line to pull chip select on the memory, which required two
217 cuts and two jumpers.
218 * The igniter sense circuits each needed a second resistor to
219 complete the voltage divider so our 3.3V CPU ADC could read the
220 5V ejection voltage. This was fixed by changing two resistor
221 values, and tacking two additional resistors onto the board
222 with jumpers to ground.
224 The schematics and PCB artwork for this version as of the working-v0.1 tag
225 are available here are pdf copies for easy reference:
227 * [schematic](v0.1/telemetrum.pdf)
228 * [pcb artwork](v0.1/telemetrum.pcb.pdf)
229 * [bill of materials](v0.1/telemetrum.bom)