This is a recording dual-deploy altimeter for high power model rocketry
with integrated telemetry link.
+<a href="v0.2 SMT side"> <img src="v0.2/cimg5164-cropped.jpg"></a>
+<a href="v0.2 connector side"> <img src="v0.2/cimg5171-cropped.jpg"></a>
<a href="loadedpair.jpg"> <img src="loadedpair-thumb.jpg"></a>
<a href="rawfront.jpg"> <img src="rawfront-thumb.jpg"></a>
<a href="rawback.jpg"> <img src="rawback-thumb.jpg"></a>
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!
+simplify things by building a new altimeter with integrated RF link! And
+after gaining some experience in 2009 with a first version, we realized we
+always want GPS on board, which lead to our current second generation boards.
## Features ##
* 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
+* Barometric pressure sensor good to 45k feet MSL
* Temperature sensor
* 1-axis high-g accelerometer for motor characterization
* 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
-* Designed to fit 29mm airframe coupler tube
+* 2.5 x 1 inch board designed to fit inside 29mm airframe coupler tube
### Developer View ###
* 32k Flash
* 4k RAM
* USB 2.0
- * analog, digital, and serial I/O
+ * 6 12-bit analog inputs (11 bits with single-ended sensors)
+ * 2 channels of serial I/O
+ * digital I/O
* [Microchip 25LC1024](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en520389) CMOS serial EEPROM
* 128k x 8
* SPI interface
* Runs from on-chip flash, uses on-chip RAM, stores flight data to
serial EEPROM 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) ##
+
## Problems ##
* The CC1111F32 is a 36-pin QFN package, which necessitates reflow
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
## Artifacts ##
The hardware design current gEDA files are available from
-[git.gag.com](http://git.gag.com).
-
-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!
+[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. The 'v0.2' and 'v0.1' branches document what we're actually flying
+right now on the two 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'.
+
+For those who don't have ready access to the gEDA suite, here are pdf snapshots
+of files in more easily readable form.
+
+* These are from the v0.2 branch:
+ * [schematic](v0.2/telemetrum.pdf)
+ * [pcb artwork](v0.2/telemetrum.pcb.pdf)
+ * [bill of materials](v0.2/partslist.csv)
+* These are as of the working-v0.1 tag:
+ * [schematic](v0.1/telemetrum.pdf)
+ * [pcb artwork](v0.1/telemetrum.pcb.pdf)
+ * [bill of materials](v0.1/telemetrum.bom)
+
+We have firmware that works well enough that we now routinely allow TeleMetrum
+to control flights by firing ejection charges. We've flown v0.1 boards in
+rockets exceeding 50g acceleration, above Mach 1, and to altitudes greater
+than 12k feet AGL with great results. Keith wrote a ground station program
+called
+ao-view that logs telemetry to disk, displays current and max
+values for key parameters during flight, and even includes voice synthesis
+during the flight so that our eyes can stay on the rockets! We have post
+flight analysis software that makes it easy to extract data from the board,
+analyze it, and even generate KML files for viewing flights in GoogleEarth!
+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 ##
+
+Work is underway on a second revision of TeleMetrum with the following changes:
+
+* stretch board length by 0.25 inches
+* adjust USB connector position to be flush with edge of board
+* eliminate temperature sensor, since baro sensor is already compensated and there's a sensor on the cc1111
+* eliminate serial port connector
+* integrate SkyTraq Venus GPS receiver and patch antenna on-board
+* change debug connector to 4 pin Tyco MicroMaTch
+* add 8 pin Tyco MicroMaTch connector for companion board interface
+* use v_lipo as pyro power, eliminating the huge 1000uF capacitor and instead
+ adding ballast capacitance on the 3.3V rail to prevent brownouts
+* move all connectors, beeper, and GPS patch antenna to the "other side" of the board from the surface mount parts
+* add a rectangle of silk screen material for improved serial number labeling
+
+As of early December 2009, the layout work for v0.2 is done and we're busy
+verifying it and deciding exactly how we're going to build them. We hope to
+have first prototypes to test in time to show the new version at LCA in late
+January 2010. If it works out as well as we hope, v0.2 may be made available
+in assembled and tested form to others in the rocketry hobby who have
+expressed interest sometime in 2010.
projects / web / altusmetrum / blobdiff