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. 2011.10.27 - looks like DK 644-1056-1-ND may be a good 32mhz rock choice for the cc1120 2011.06.11 - thinking about what a second-generation TeleMetrum might be like - board width sized to fit inside 38mm coupler .. say, 32mm wide - ARM cpu w/USB interface - STM32L151RBT6 DK 497-11193-ND 4.81 @ q100 - 32Mhz Cortex M3 - 128kx8 flash, 16kx8 RAM, 4kx8 EEPROM - 64-LQFP with 51 i/o pins (48 or 100 pin variants) - 20 x 12b ADC, 2 x 12b DAC - 2 spi, 2 i2c, 3 usart, usb - 1.8 or 3.3V, very low power - needs 1-24 Mhz crystal - cc1120 transceiver - SPI target with improved performance over cc1111 - QFN-32 - 50mA typical power drain TX in 70cm band, 22mA receive - wants 32 Mhz crystal - maybe with a switched amplifier and preamp? - can be used with the CC1190 on the 900mhz band (not useful) - more than 2 pyro channels - 10 screws are 25.86mm wide - 12 screws are 30.94mm wide - a better plan would be to put two screw strips back to back aligned with the major axis of the board, so that wires come out either side instead of to the rear? - definitely want to support use of separate pyro battery, need to think about the best way to do that. - GPS can we get high dynamic firmware from Skytraq, or do we need to change to a different vendor? - baro MS5607 .. I2C or SPI, 10 to 1200 mbar, 1uA, DFN-8'ish - accel 1-axis high-G for motor characterization MMA6556KWR2 .. SPI, 1 axis, +-120g, 7mA max, QFN-16 3-axis medium-G for orientation .. all are I2C or SPI Bosch BMA250 16g, 8hz-1khz, 32lsb/g 3.07 q100 ST LIS331HH 24g, 50hz-1khz, 3mg/digit 4.89 q100 Analog ADXL345 16g, 6.25hz-3.2khz, 32lsb/g 5.88 q100 - 3-axis gyro ST L3G3250A 2000dps, analog out (not really available?) ST L3G4200D 2000dps, I2C or SPI, 1 ADC + mux ITG-3200 2000dps, I2C only, 3 ADCs ITG-3050 2000dps, I2C only, 3 ADCs, with low noise and better sensitivity than the 3200? Invensense also has an IMU-3000 that is like the above gyro parts but can have a 3-axis accel as i2c slave and will do the navigation computing. $12 vs $10 each. The MPU-6000/6050 is the holy grail, 3-axis gyro and accel on one chip that outputs nav solutions... but it's not shipping yet. 2011.06.30 - keithp points out that in the STM32L151 family, only the 100 pin versions expose the second SPI port. STM32L151VBT6 is DK 497-11195-ND, $5.38 @ q100 - 32Mhz Cortex M3 - 128kx8 flash, 16kx8 RAM, 4kx8 EEPROM - 100-LQFP (14x14mm) with 83 i/o pins (48 or 64 pin variants) - 24 x 12b ADC, 2 x 12b DAC - 2 spi, 2 i2c, 3 usart, usb - 1.8 or 3.3V, very low power 2011.11.23 - decisions based on IRC conversation with keithp + GPS on usart3 PC10/11 doesn't conflict with the serial bootloader - pick either usart1 or usart2 on PD5/6 or PA9/10 for bootloader - flash and companion can share an SPI, sensors need dedicated SPI - use 3 screws for v_pyro, either jumper to tie to v_lipo or attach separate battery .. plan to ship boards with the jumper installed - 2 screws for power switch - 6 pyro channels, 2 screws per channel = 12 screws - 2-pin 2mm box connector for primary lipo - same lipo charger as on lipocharger, set for 500ma charge rate - include a screw attached to ground, easy attach for magnetic switch - that makes 18 screws, use two 9's back to back - silicon q100 $ - STM32L151VBT6 Cortex-M3 SOC 5.39 - CC1120 digital radio spi2 6.60 - W25Q64BVZEIG 64Mbit flash spi2 2.06 - sensors - Freescale MMA6556KWR2 120g 1-axis accel spi1 5.00 - Bosch BMA250 16g 3-axis accel spi1 3.07 - Meas Spec MS5607 baro sensor spi1 6.35 - ITG-3200 2000 deg/sec 3-axis gyro i2c1 8.00 - SkyTraq Venus 638 GPS usart3 10.00 - companion port spi2 i2c2 bootloader intf usart1 usart2 To Do - tweak up the paste mask dimensions and so forth on BMA250.py, which is sort of crude at the moment .. see page 68 of the BMA250 data sheet 2011.11.29 - Eleazar Zuniga says in email of 28 Nov 2011 that we should be able to use any of the pin or SMT patches other than the 35mm ones, as long as we have ground plane under the patch itself that's as large as the patch or bigger. I'm not sure I believe that, but adding an 0402 site to ground for a tuning cap ala what the chip antenna docs call for might be a reasonable thing to try? pinned versions GP.1575.12.4.A.02 12x12x4 mm, pin plus adhesive gain towards zenith -0.5 dBic GP.1575.15.4.B.02 15x15x4 mm, pin plus adhesive 1.0 dBic at zenith GP.1575.18.2.A.02 18x18x2 mm, pin plus adhesive gain towards zenith -0.5 dBic GP.1575.18.4.A.02 18x18x4 mm, pin plus adhesive gain towards zenith +3.5 dBic $4.13 at q100 *** 50% the mass of 25mm GP.1575.25.2.A.02 25x25x2 mm, pin plus adhesive +2.0 dBic gain at zenith GP.1575.25.4.A.02 25x25x4 mm, pin plus adhesive gain towards zenith +3.5 dBic $4.05 at q100 surface-mount versions SGP.1575.12.4.A.02 12x12x4.5 mm -2.0 dBic at zenith, 4dB axial ratio, 6Mhz bandwidth SGP.1575.15.4.A.02 15x15x4.5 mm +1.0 dBic at zenith, 3dB axial ratio, 6Mhz bandwidth SGP.1575.18.4.C.02 18x18x4.5 mm +1.0 dBic at zenith, 4dB axial ratio, 5Mhz bandwidth $4.94 at q100 SGP.1575.25.4.C.02 25x25x4.5 mm +2.0 dBic at zenith, 3dB axial ratio, 5Mhz bandwidth By comparison the data on the chip antenna from Pulse Engineering we're trying out on TeleTerra is: W3011A required PCB surface around around 6x8 mm on a board edge +1.0 dBic peak $1.28 at q100 From all of this, GP.1575.18.4.A.02 would seem to be the clear winner. It has 2.5 dB more gain than the chip antenna at the expense of a bit more mass. However, if the chip antenna performance is "adequate", it saves surface area, mass, and BOM cost. 2011.12.01 - traded email with Invensense, their US distributor is cdiweb.com, they have ITG-3200 in stock for $10 each and $8 in q100, and they have the new IMU-6000 gyro+accel part for $15 each or $13 at q100. http://www.cdiweb.com/Manufacturers/invensense http://www.cdiweb.com/ProductDetail/ITG3200/405256 http://www.cdiweb.com/ProductDetail/MPU6000/420595 2012.02.06 - so where are we... - silicon q100 $ - STM32L151VBT6 Cortex-M3 SOC 5.39 - CC1120 digital radio spi2 6.60 - W25Q64BVZEIG 64Mbit flash spi2 2.06 - sensors - Freescale MMA6556KWR2 120g 1-axis accel spi1 5.00 - Meas Spec MS5607 baro sensor spi1 6.35 - IMU-6000 gyro+accel 13.00 - SkyTraq Venus 638 GPS usart3 10.00 - Honeywell HMC5883L magnetic sensor - companion port spi2 i2c2 bootloader intf usart1 usart2