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 store.
9 These are photos of our current production version, which includes an
10 integrated GPS receiver with active patch antenna:
12 <a href="v1.0/cimg5972-crop.jpg"> <img src="v1.0/cimg5972-thumb.jpg"></a>
13 <a href="v1.0/cimg5974-crop.jpg"> <img src="v1.0/cimg5974-thumb.jpg"></a>
17 Bdale and Keith both own
18 [BeeLine](http://www.bigredbee.com/BeeLine.htm)
20 [Big Red Bee](http://www.bigredbee.com), and are pretty happy with them.
21 They use a PIC processor and a TI CC1050 transmitter chip, and
22 operate in the ham radio 70cm band.
24 One weekend while attending a conference together, we got to wondering if
25 we couldn't adapt one to use as a downlink for the
26 [AltusMetrum](../AltusMetrum/) altimeter board in addition to direction
27 finding after flight. That caused us to start thinking about other things
28 in the design we might want to tweak, and before long we were working on the
29 design of a new tracker board derived from the BeeLine design.
30 Another friend at the same conference showed us a board he was working on
31 using a different part in the same TI series, that integrated a transceiver
32 and CPU on the same chip.
33 It didn't take us long to realize that with such a part we could combine and
34 simplify things by building a new altimeter with integrated RF link! And
35 after gaining some experience in 2009 with a first version, we realized we
36 always want GPS on board, which lead to our current second generation boards.
42 * Recording altimeter for model rocketry
43 * Supports dual deployment (can fire 2 ejection charges)
44 * 70cm ham-band transceiver for telemetry downlink
45 * Barometric pressure sensor good to 45k feet MSL
46 * 1-axis high-g accelerometer for motor characterization
47 * On-board, integrated GPS receiver
48 * On-board non-volatile memory for flight data storage
49 * USB for power, configuration, and data recovery
50 * Integrated support for LiPo rechargeable batteries
51 * Uses LiPo to fire e-matches, optional support for separate pyro battery
52 * 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube
54 ### Developer View ###
57 * [TI CC1111F32](http://focus.ti.com/docs/prod/folders/print/cc1111f32.html) Low Power RF System-on-Chip
58 * Sub-1Ghz transceiver
63 * 6 12-bit analog inputs (11 bits with single-ended sensors)
64 * 2 channels of serial I/O
66 * [Atmel AT45DB081D](http://www.atmel.com/dyn/products/product_card.asp?part_id=3819) DataFlash memory
70 * other parts in this Atmel DataFlash series can optionally be used
71 * [SkyTraq](http://www.skytraq.com.tw/) Venus634FLPx GPS receiver
72 * on-board [Taoglas AP.17A.01](http://www.taoglas.com/antennas/GPS_Antennas/Internal_GPS_-_Active_Patch_Modules/)
73 single-stage active patch antenna
74 * U.FL connector with 3.3V DC can be re-purposed for optional external amplified antennas
75 * async serial interface
76 * [Freescale MP3H6115A](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MP3H6115A6U) pressure sensor
77 * [Freescale MMA2202EG](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MMA2202EG) 50g accelerometer. Can use 40-200g variants!
79 * Written mostly in C with some 8051 assembler
80 * Runs from on-chip flash, uses on-chip RAM, stores flight data to
82 * USB serial emulation for "console" interface
84 * [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
85 * [SDCC](http://sdcc.sourceforge.net/) compiler and source debugger
87 * The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
88 * The software is licensed [GPL version 2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html)
90 ## [Production History](../production) ##
92 ## [Flight Logs](flightlogs) ##
96 The user manual for TeleMetrum is available in
97 [html](doc/telemetrum-doc.html) and [pdf](doc/telemetrum-doc.pdf)
100 The hardware design current gEDA files are available from
101 [git.gag.com](http://git.gag.com) in the project
102 [hw/telemetrum](http://git.gag.com/?p=hw/telemetrum;a=summary).
104 Work on the next version proceeds on the master branch, with occasional
105 temporary branches created when Bdale is making some major / speculative
106 change. The 'v0.2' and 'v0.1' branches document what we're actually flying
107 right now on the two respective PCB revisions. The 'ground' branch has a
108 cut-down schematic used to generate the BOM for partially loading v0.1 boards
109 to used on the ground. We call the on-the-ground version 'TeleDongle'.
111 For those who don't have ready access to the gEDA suite, here are pdf snapshots
112 of the files for Production PCB version 1.0 in more easily readable form.
114 * [schematic](v1.0/telemetrum.pdf)
115 * [pcb artwork](v1.0/telemetrum.pcb.pdf)
116 * [bill of materials](v1.0/partslist.csv)
118 Our [AltOS](../AltOS) firmware works well enough that we now routinely fly
119 TeleMetrum with no backup. Rockets with v0.1 boards have exceeded 50g
120 acceleration, been above Mach 1, and reached altitudes greater
121 than 12k feet AGL with great results. Keith's ground station program
122 called ao-view logs telemetry to disk, displays current and max values for
123 key parameters during flight, and even includes voice synthesis
124 during the flight so that our eyes can stay on the rockets! We have post
125 flight analysis software that makes it easy to extract data from the board,
126 analyze it, and even generate KML files for viewing flights in GoogleEarth!
127 More details on the software, including full source code and pre-built packages
128 can be found on the [AltOS](../AltOS) page on this site.
132 As of May 2010, version v1.0 is available for sale from the
133 [Garbee and Garbee](http://auric.gag.com) web store.
135 Because we understand that not everyone uses Linux, development of a new
136 cross-platform ground station program written in Java is underway for use with
141 * The CC1111F32 is a 36-pin QFN package, which necessitates reflow
142 soldering. Since we needed to reflow solder anyway, and because TI used
143 them in their reference design, we went a little crazy and used 0402
144 passive parts everywhere. That means working under a microscope to
145 place parts! Without an inspection microscope, loading and testing these
146 boards might be impossible.
148 * The addition of on-board GPS in v0.2 means that the total power consumption
149 can exceed the rate at which we draw power from the USB interface,
150 particularly when the GPS is in cold start mode. This means a battery must
151 be attached during operation, and also that the battery will only charge
152 effectively from USB when the board is turned off.
158 * 100ma LDO regulator instead of the current 150ma part
160 * different value for C36 reset capacitor
162 These are photos of our second version, which included the integrated Venus
163 GPS receiver, but with a passive patch antenna that turned out to have
164 disappointing performance due to our many PCB geometry constraints. It also
165 used a voltage regulator with less capacity which we felt was marginal for
166 supporting the companion boards we have planned:
168 <a href="v0.2/cimg5164-cropped.jpg"> <img src="v0.2/cimg5164-thumb.jpg"></a>
169 <a href="v0.2/cimg5171-cropped.jpg"> <img src="v0.2/cimg5171-thumb.jpg"></a>
171 Other than cleaning up the silkscreen, the differences between v0.2 and our
172 current v1.0 boards were really quite small:
174 * 100ma LDO regulator instead of the current 150ma part
176 * different value for C36 reset capacitor
178 The schematics and PCB artwork for this version are on the v0.2 branch in
179 our git repository, here are pdf copies for easy reference:
181 * [schematic](v0.2/telemetrum.pdf)
182 * [pcb artwork](v0.2/telemetrum.pcb.pdf)
183 * [bill of materials](v0.2/partslist.csv)
187 And this is a photo of our original board with serial port for off-board GPS,
188 without the big off-board 1000uF cap from the original ejection circuit:
190 <a href="v0.1/loadedpair.jpg"> <img src="v0.1/loadedpair-thumb.jpg"></a>
192 The differences between v0.1 and later boards were more substantial:
194 * 2.5 x 1 inch board with all parts mounted on one side
195 * 4-pin PicoBlade serial port connector for attachment of external GPS module
196 * USB connector projected approximately 3mm over the edge of the board
197 * Debug connector used 4 IC socket pins on 100 mil centers
198 * no companion board interface
199 * 50ma LDO regulator on early boards, later boards used a 100ma part
200 * [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM instead of DataFlash
203 * [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) discrete temperature sensor
204 * used 1000uF electrolytic capacitor charged to 5V for pyro supply
205 * two LEDs instead of one attached to CPU
207 The elimination of the discrete temperature sensor and second LED were
208 necessary to support the companion board interface added in v0.2.
210 The v0.1 artwork had three issues, two of which required physical rework
211 on each board. All of these issues were fixed in v0.2.
213 * The USB connector footprint was placed wrong, so that the
214 connector hung out over the edge of the board instead of being
216 * We needed chip select on the SPI memory. To fix that, we gave up the
217 ability to put the accelerometer into self-test mode and used that
218 GPIO line to pull chip select on the memory, which required two
219 cuts and two jumpers.
220 * The igniter sense circuits each needed a second resistor to
221 complete the voltage divider so our 3.3V CPU ADC could read the
222 5V ejection voltage. This was fixed by changing two resistor
223 values, and tacking two additional resistors onto the board
224 with jumpers to ground.
226 The schematics and PCB artwork for this version as of the working-v0.1 tag
227 are available here are pdf copies for easy reference:
229 * [schematic](v0.1/telemetrum.pdf)
230 * [pcb artwork](v0.1/telemetrum.pcb.pdf)
231 * [bill of materials](v0.1/telemetrum.bom)