From 415edfec216fb96e224120de746155cc652a4c1b Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Sat, 6 Feb 2010 12:57:12 -0700 Subject: [PATCH] more restructuring --- TeleMetrum/index.mdwn | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/TeleMetrum/index.mdwn b/TeleMetrum/index.mdwn index 93550e3..a98fcac 100644 --- a/TeleMetrum/index.mdwn +++ b/TeleMetrum/index.mdwn @@ -98,8 +98,11 @@ always want GPS on board, which lead to our current second generation boards. * [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) temperature sensor instead of using cc1111 on-chip sensor -* used 1000uF electrolytic capacitor charged to 5V for pyro charges +* [Microchip MCP9700A](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en027103) discrete temperature sensor + * eliminated in v0.2 to free GPIO line for companion interface +* used 1000uF electrolytic capacitor charged to 5V for pyro supply +* two LEDs instead of one attached to CPU + * eliminated second LED to free GPIO line for companion interface ## [Production History](production) ## @@ -114,18 +117,21 @@ always want GPS on board, which lead to our current second generation boards. 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 - to pull chip select on the memory. The second is that the igniter sense - circuits each need a second resistor to complete the voltage divider so our - 3.3V CPU ADC can read the 5V ejection voltage. This is fixed by changing - two resistor values, and tacking two additional resistors onto the board - with jumpers to ground. +* 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. ## Artifacts ## -- 2.47.2