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 starter kits are also now available from
9 [Apogee Components](http://www.apogeerockets.com/Altus_Metrum_GPS.asp).
11 For the latest TeleMetrum firmware and related ground station software, please
12 visit the [AltOS](../AltOS) page on this site.
14 These are photos of our current production version, which includes an
15 integrated GPS receiver with active patch antenna:
17 <a href="v1.0/cimg5972-crop.jpg"> <img src="v1.0/cimg5972-thumb.jpg"></a>
18 <a href="v1.0/cimg5974-crop.jpg"> <img src="v1.0/cimg5974-thumb.jpg"></a>
22 Bdale and Keith both own
23 [BeeLine](http://www.bigredbee.com/BeeLine.htm)
25 [Big Red Bee](http://www.bigredbee.com), and are pretty happy with them.
26 They use a PIC processor and a TI CC1050 transmitter chip, and
27 operate in the ham radio 70cm band.
29 One weekend while attending a conference together, we got to wondering if
30 we couldn't adapt one to use as a downlink for the
31 [OpenAlt](../OpenAlt/) altimeter board in addition to direction
32 finding after flight. That caused us to start thinking about other things
33 in the design we might want to tweak, and before long we were working on the
34 design of a new tracker board derived from the BeeLine design.
35 Another friend at the same conference showed us a board he was working on
36 using a different part in the same TI series, that integrated a transceiver
37 and CPU on the same chip.
38 It didn't take us long to realize that with such a part we could combine and
39 simplify things by building a new altimeter with integrated RF link! And
40 after gaining some experience in 2009 with a first version, we realized we
41 always want GPS on board, which lead to our current second generation boards.
47 * Recording altimeter for model rocketry
48 * Supports dual deployment (can fire 2 ejection charges)
49 * 70cm ham-band transceiver for telemetry downlink
50 * Barometric pressure sensor good to 45k feet MSL
51 * 1-axis high-g accelerometer for motor characterization
52 * On-board, integrated GPS receiver
53 * On-board non-volatile memory for flight data storage
54 * USB for power, configuration, and data recovery
55 * Integrated support for LiPo rechargeable batteries
56 * Uses LiPo to fire e-matches, can be modified to support separate pyro battery
57 * 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube
59 ### Developer View ###
62 * [TI CC1111F32](http://focus.ti.com/docs/prod/folders/print/cc1111f32.html) Low Power RF System-on-Chip
63 * Sub-1Ghz transceiver
68 * 6 12-bit analog inputs (11 bits with single-ended sensors)
69 * 2 channels of serial I/O
71 * [Atmel AT45DB081D](http://www.atmel.com/dyn/products/product_card.asp?part_id=3819) DataFlash memory
75 * other parts in this Atmel DataFlash series can optionally be used
76 * [SkyTraq](http://www.skytraq.com.tw/) Venus634FLPx GPS receiver
77 * on-board [Taoglas AP.17A.01](http://www.taoglas.com/antennas/GPS_Antennas/Internal_GPS_-_Active_Patch_Modules/)
78 single-stage active patch antenna
79 * U.FL connector with 3.3V DC can be re-purposed for optional external amplified antennas
80 * async serial interface
81 * [Freescale MP3H6115A](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MP3H6115A6U) pressure sensor
82 * [Freescale MMA2202EG](http://www.freescale.com/webapp/search.partparamdetail.framework?PART_NUMBER=MMA2202EG) 50g accelerometer. Can use 40-200g variants!
84 * Written mostly in C with some 8051 assembler
85 * Runs from on-chip flash, uses on-chip RAM, stores flight data to
87 * USB serial emulation for "console" interface
89 * [gEDA](http://www.gpleda.org/) for schematic capture and PCB layout
90 * [SDCC](http://sdcc.sourceforge.net/) compiler and source debugger
92 * The hardware is licensed under the [TAPR](http://www.tapr.org) [Open Hardware License](http://www.tapr.org/ohl.html)
93 * The software is licensed [GPL version 2](http://www.gnu.org/licenses/old-licenses/gpl-2.0.html)
95 ## [Production History](../production) ##
97 ## [Flight Logs](flightlogs) ##
101 There is a single manual for TeleMetrum and all other Altus Metrum products,
102 which is available in [html](../AltOS/doc/altusmetrum.html) and
103 [pdf](../AltOS/doc/altusmetrum.pdf) formats.
105 The hardware design current gEDA files are available from
106 [git.gag.com](http://git.gag.com) in the project
107 [hw/telemetrum](http://git.gag.com/?p=hw/telemetrum;a=summary).
109 Work on the next version proceeds on the master branch, with occasional
110 temporary branches created when Bdale is making some major / speculative
111 change. The 'v0.2' and 'v0.1' branches document what we're actually flying
112 right now on the two respective PCB revisions. The 'ground' branch has a
113 cut-down schematic used to generate the BOM for partially loading v0.1 boards
114 to used on the ground. We call the on-the-ground
115 version '[TeleDongle](../TeleDongle)', and newer versions have their own PCB
118 For those who don't have ready access to the gEDA suite, here are pdf snapshots
119 of the files for Production PCB version 1.0 in more easily readable form.
121 * [schematic](v1.0/telemetrum.pdf)
122 * [pcb artwork](v1.0/telemetrum.pcb.pdf)
123 * [bill of materials](v1.0/partslist.csv)
125 We consider our [AltOS](../AltOS) firmware completely reliable, and routinely
126 fly TeleMetrum with no backup. Rockets with TeleMetrum boards
127 have exceeded 50g acceleration, been well above Mach 1, and reached altitudes
128 greater than 25k feet AGL with great results. Keith's second generation
129 ground station program called altosui works on Windows, Mac, and Linux systems
130 and logs telemetry to disk, displays current and max values for key parameters
131 during flight, and even includes voice synthesis during the flight so that
132 our eyes can stay on the rockets! After flight, altosui can extract the
133 complete flight log from TeleMetrum, can display plots of the data from either
134 the telemetry received by radio or the onboard flight log, can output a kml
135 file for use with [Google Earth](http://earth.google.com), and can also
136 output all the flight data as a csv file for easy import to spreadsheet
137 programs or other analysis tools allowing you to perform whatever
138 custom analysis you can envision! More details on the software,
139 including full source code and pre-built packages
140 can be found on the [AltOS](../AltOS) page on this site.
144 TeleMetrum v1.0 meets all of our expectations. We anticipate another
145 production run of boards soon, which will include minor design tweeks mostly
146 to work around component availability issues.
150 * The CC1111F32 is a 36-pin QFN package, which necessitates reflow
151 soldering. Since we needed to reflow solder anyway, and because TI used
152 them in their reference design, we went a little crazy and used 0402
153 passive parts everywhere. That means working under a microscope to
154 place parts! Without an inspection microscope, loading and testing these
155 boards might be impossible.
157 * The addition of on-board GPS in v0.2 means that the total power consumption
158 can exceed the rate at which we draw power from the USB interface,
159 particularly when the GPS is in cold start mode. This means a battery must
160 be attached during operation, and also that the battery will only charge
161 effectively from USB when the board is turned off.
167 These are photos of our second version, which included the integrated Venus
168 GPS receiver, but with a passive patch antenna that turned out to have
169 disappointing performance due to our many PCB geometry constraints. It also
170 used a voltage regulator with less capacity which we felt was marginal for
171 supporting the companion boards we have planned:
173 <a href="v0.2/cimg5164-cropped.jpg"> <img src="v0.2/cimg5164-thumb.jpg"></a>
174 <a href="v0.2/cimg5171-cropped.jpg"> <img src="v0.2/cimg5171-thumb.jpg"></a>
176 Other than cleaning up the silkscreen, the differences between v0.2 and our
177 current v1.0 boards were really quite small:
179 * 100ma LDO regulator instead of the current 150ma part
181 * different value for C36 reset capacitor
183 The schematics and PCB artwork for this version are on the v0.2 branch in
184 our git repository, here are pdf copies for easy reference:
186 * [schematic](v0.2/telemetrum.pdf)
187 * [pcb artwork](v0.2/telemetrum.pcb.pdf)
188 * [bill of materials](v0.2/partslist.csv)
192 And this is a photo of our original board with serial port for off-board GPS,
193 without the big off-board 1000uF cap from the original ejection circuit:
195 <a href="v0.1/loadedpair.jpg"> <img src="v0.1/loadedpair-thumb.jpg"></a>
197 The differences between v0.1 and later boards were substantial:
199 * 2.5 x 1 inch board with all parts mounted on one side
200 * 4-pin PicoBlade serial port connector for attachment of external GPS module
201 * USB connector projected approximately 3mm over the edge of the board
202 * Debug connector used 4 IC socket pins on 100 mil centers
203 * no companion board interface
204 * 50ma LDO regulator on early boards, later boards used a 100ma part
205 * [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM instead of DataFlash
208 * [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) discrete temperature sensor
209 * used 1000uF electrolytic capacitor charged to 5V for pyro supply
210 * two LEDs instead of one attached to CPU
212 The elimination of the discrete temperature sensor and second LED were
213 necessary to support the companion board interface added in v0.2.
215 The v0.1 artwork had three issues, two of which required physical rework
216 on each board. All of these issues were fixed in v0.2.
218 * The USB connector footprint was placed wrong, so that the
219 connector hung out over the edge of the board instead of being
221 * We needed chip select on the SPI memory. To fix that, we gave up the
222 ability to put the accelerometer into self-test mode and used that
223 GPIO line to pull chip select on the memory, which required two
224 cuts and two jumpers.
225 * The igniter sense circuits each needed a second resistor to
226 complete the voltage divider so our 3.3V CPU ADC could read the
227 5V ejection voltage. This was fixed by changing two resistor
228 values, and tacking two additional resistors onto the board
229 with jumpers to ground.
231 The schematics and PCB artwork for this version as of the working-v0.1 tag
232 are available here are pdf copies for easy reference:
234 * [schematic](v0.1/telemetrum.pdf)
235 * [pcb artwork](v0.1/telemetrum.pcb.pdf)
236 * [bill of materials](v0.1/telemetrum.bom)