From 8cfe0a4f3d081f25611edc85ba3e19ed357b10c3 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Mon, 26 Dec 2011 15:35:08 -0700 Subject: [PATCH] add a history of TeleMetrum page and link it from the index --- TeleMetrum/history.mdwn | 115 ++++++++++++++++++++++++++++++++++++++++ TeleMetrum/index.mdwn | 100 +--------------------------------- 2 files changed, 116 insertions(+), 99 deletions(-) create mode 100644 TeleMetrum/history.mdwn diff --git a/TeleMetrum/history.mdwn b/TeleMetrum/history.mdwn new file mode 100644 index 0000000..d14f2de --- /dev/null +++ b/TeleMetrum/history.mdwn @@ -0,0 +1,115 @@ +# TeleMetrum History + +## v0.1 ## + +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. + +The schematics and PCB artwork for this version as of the working-v0.1 tag +are available here are pdf copies for easy reference: + + * [schematic](v0.1/telemetrum.pdf) + * [pcb artwork](v0.1/telemetrum.pcb.pdf) + * [bill of materials](v0.1/telemetrum.bom) + +## 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) + +## 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 +* updated reset circuit to improve reliability at temperature extremes +* 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) + +## v1.1 ## + + + + +For those who don't have ready access to the gEDA suite, here are pdf snapshots +of the files for Production PCB version 1.1 in more easily readable form. + +* [schematic](v1.1/telemetrum.pdf) +* [pcb artwork](v1.1/telemetrum.pcb.pdf) +* [bill of materials](v1.1/partslist.csv) + +## v1.2 ## + +Our current production version. diff --git a/TeleMetrum/index.mdwn b/TeleMetrum/index.mdwn index 31c6694..bac3334 100644 --- a/TeleMetrum/index.mdwn +++ b/TeleMetrum/index.mdwn @@ -139,103 +139,5 @@ will be posted here when they're available to order. be attached during operation, and also that the battery will only charge effectively from USB when the board is turned off. -## History ## +## [History of TeleMetrum](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 -* updated reset circuit to improve reliability at temperature extremes -* 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. - -The schematics and PCB artwork for this version as of the working-v0.1 tag -are available here are pdf copies for easy reference: - - * [schematic](v0.1/telemetrum.pdf) - * [pcb artwork](v0.1/telemetrum.pcb.pdf) - * [bill of materials](v0.1/telemetrum.bom) -- 2.39.5