lose the "pad" in the GPS patch footprint

[hw/telemetrum] / Notebook

diff --git a/Notebook b/Notebook
index ab111a417377d4b9b71b0b6bd13b307e8112c89e..07b22c7da567101c05f0b9fba2efaa5a9963b0c9 100644 (file)
--- a/Notebook
+++ b/Notebook
@@ -105,8 +105,12 @@
   Keith found gps active antennas with cable to U.FL connectors and Molex sells
   cables with U.FL to bare leads, so this should cover the bases.
 
   Keith found gps active antennas with cable to U.FL connectors and Molex sells
   cables with U.FL to bare leads, so this should cover the bases.
 

-- TelePyro doesn't need a CPU.  How about an SPI to I2C converter chip with
-  GPIO lines and an I2C ADC chip?
+- TelePyro doesn't really need a CPU.  How about an SPI to I2C converter chip 
+  with GPIO lines and an I2C ADC chip?  Cheaper and easier than a PIC?
+
+       PIC16F882 in SSOP-28 is $2.10 per, 1.41 @ 25 units
+         -- PIC16F883 is $2.12, PIC16F886 is $2.32, have better memories
+       CP2120 in QFN-20 is     $2.41 per, 2.27 @ 25 units

 
   The Silabs CP2120 has 8 gpio lines but is only available in QFN20.  The NXP
   part I discovered earlier, the SC18IS600, has 4 full gpio lines and 2 lame-o
 
   The Silabs CP2120 has 8 gpio lines but is only available in QFN20.  The NXP
   part I discovered earlier, the SC18IS600, has 4 full gpio lines and 2 lame-o


@@ -143,3 +147,76 @@
 - another way to think about all this is that I could panelize a set of boards
   all done in 2 layers, then treat that as a sub-panel I put N copies down of
   to fill up a 33each.com max panel size.
 - another way to think about all this is that I could panelize a set of boards
   all done in 2 layers, then treat that as a sub-panel I put N copies down of
   to fill up a 33each.com max panel size.

+
+2009.10.16
+- move to AT45DB161D 16-megabit SPI "DataFlash" EEPROM from Atmel?
+       AT45DB161D-SU-ND in SOIC-8 for $2.26 each
+  appears to compare favorably against $4.40 for current 128kx8 part
+  minor concern about write power, but probably red herring
+
+2010.02.08
+- looking at LiPo charger alternatives
+
+       MAX8808         DFN8, not carried by DK
+       MAX8814         DFN8, not carried by DK
+
+       LTC4095         DFN8, LTC4095EDC#TRMPBFCT-ND 2.91 2.34@100
+               950mA, resistor current set, rate limit input, suspend input,
+               NTC thermal control option, smart CHRG led with 4 states
+       LTC4065         DFN6, LTC4065EDC#TRMPBFCT-ND 2.77 2.23@100
+               750mA, resistor current set, CHRG led, enable input
+       LTC4065A        DFN6, LTC4065AEDC#TRMPBFCT-ND 2.77 2.23@100
+               750mA, resistor current set, CHRG led, supply present out
+               
+       MCP73811        SOT23-5, MCP73811T-420I/OTCT-ND 0.63@1 0.39@100
+               input selects 85 vs 450mA charge current
+
+       MCP73837        DFN10, MCP73837T-FCI/MFCT-ND 1.37@1 0.85@100
+               usb rate select, power good output, dual inputs, dual status
+
+       LX2206          DFN10, LX2206CT-ND 2.68@1 2.01@100
+               rate select, power good output... needs more passives?
+
+       LM3658          DFN10, 
+               dual input, dual rate, two status outputs .. not obvious win
+
+       MCP73855        DFN10, MCP73855T-I/MFCT-ND 1.85@1 1.18@100
+               see Microchip app note 971
+
+
+  Talking to Keith, there's no reason we couldn't use an 8-pin PIC to augment
+  a standalone LiPo charger, implementing a timer after vusb application 
+  before switching the regulator to high current, to allow the cc1111 time to
+  finish the USB bus negotiation phase.  We could also monitor various state
+  bits and multiplex signaling onto one LED.  A combo like the MCP73837 plus
+  a PIC10F206 or 220 would net under $1.50 at 100 pieces and be pretty 
+  powerful.  Since the PIC has avilable weak pull-ups on the gpio lines, the
+  open-drain state outputs from the regulator don't need resistors to be read.
+
+2011.01.17
+- v1.0 and v1.1 boards have a minor error in that the v_lipo sampling resistors
+  are on "the wrong side of the cut" if you try to use a separate pyro battery.
+  The workaround is to cut that trace and put in a jumper, which pretty much
+  requires "return to Bdale for rework".  We should fix this for a future PCB
+  revision.
+
+2011.09.12
+- chatted with Adrian some yesterday.  He likes a Bosch pressure sensor that
+  is DK 828-1005-1-ND .. i2c output, similar range to our current part but
+  smaller, around $5 at our build quantities.
+
+2011.12.10
+- the Johanson balun/filter for 70cm use with cc1111 is DK 712-1540-1-ND
+  uses less PCB area, but lower performance than the discrete approach
+
+2013.01.04
+- noodling over TM v2.0 .. baro sensor will be hard to handle on cc1111.  So,
+  how about 48-pin version of STM32L, cc110L radio, ms5607 and MMA665X accel.
+  Move to the faster lipo charger, too.
+       radio / flash on spi2, sensors on spi1, baro on spi1 alternate pins
+
+2013.05.02
+- serious stab at what should be on TeleMetrum v2 .. used cc115L section from
+  TeleGPS since I didn't have a cc110L data sheet on the plane .. hope it's
+  similar .. need to update to transceiver, not just transmitter!
+