Version 0.1 bugs and things to improve

✔ 5V enable line is shorted to groundplane. Should be cut on both sides. Leave floating on uC side and bridge to Battery input pin on boost converter.

✔ The 3.3V linear regulator does not work with 3.7V battery input! One possible solution for this board would be to connect it to 5V output. Next versions should use a LiIon-to-3.3V IC or adapt the power subsystem of the swisscube.

✔ There is no accessible GND, 3.3V and 5V pin. Should be added in next version!

✔ Resolve uncommon resistor values with serial or parallel combinations (e.g. 21.5k to 20k + 1.5k) for easier bills of materials.

✔ Space the pins with equal distances, so you dont have to cut the headers too often.

✔ label SBW pins with TST and RST

✔ Recommendation for MSP430: Crystal capacitances' ground connection should be closely together and eventually put a guard ring around it (if NC pins are next to XIN and XOUT pins).

Recommendation in Compass datasheet: ✔ Stencil Design and Solder Paste: A 4 mil stencil and 100% paste coverage is recommended for the electrical contact pads.

✔ The silk layer of v0.1 has wrong (too uncommon) resistor values at the output loop of the 5V booster. They should be replaced by 270k and 68k as in the newest v0.1 Eagle file.

✔ The Energia libraries do not support UCB1 serial output. Connect the I2C lines to the pins of UCB0 output.

It would be better to operate the H-bridges in In1/In2-mode → tie the phase pin to ground instead of VDD.

-Heat pad transistors must have a mosfet stage before the power transistor, as it will draw too much power. As well, its base was not connected to anything.

✔ The footprint of the 5V boost converter did not exist in stencil → change package layers!

Version 0.4 bugs and things to improve

- Caps around crystal and resistors next to it are 0402 instead of 0603. –> check all with the BOM export tool

- Flash memory SST25VF064C is obsolete - use equivalent SST26VF064B

Version 0.5 bugs and things to improve

- Add dedicated ultrasonic pins in next version with 5V supply and resistive dividers at input.

✔ change the FLASH_CS pin to 5.5 to release an input capture pin

✔ release motor pins to make input capture pins accessible. - use pin 8.2 for input caputre. - use pin 10.3 for input capture.

✔ Dont supply the current sensing amplifiers with a GPIO pin, but keep them supplied constantly (or turn off V-ref simultanously). vref can be maximum (V+) +0.3V

- make sure all vias are covered with “green colour” , especially below LoRa module.

- !!! Only the pins with TAx.X support PWM and input capture. treat them accordingly (and connect to motor enable) or use port mapping for these!!!

✔ Revisit the location of the 10uF polarized caps.

✔ Change RX0/TX0 on header

Version 0.6 bugs and things to improve

✔ Draw “forward” direction of IMU on silkscreen

✔ H-bridges: Bypass VCC 12 - Device supply to GND with a 0.1-μF (minimum) ceramic capacitor and increase Vm cap to 10uF. (drv8835).

✔ PWM for h-bridges: P8.0 and 8.1 can not be used for PWM (CCR0 never a good idea…) Either change h-bridge mode to IN/IN (gnd) or change enable pins.

✔ Power headers: also transform GND pins to SMD to adjust height to VDD

✔ Lightning sensor interrupt: should have CCR to measure frequency in calibration mode.

✔ BNO055 Input caps: verify values and separate 100nF and 10nF.

- Add ESD protection for I2C, (SPI, UART and supply).

- Add SPI resistors if needed

✔ Silk screen AGND A1 is wrong

(✔) replace tantalum caps by ceramic

Version 1.0 bugs and things to improve

-Flash: (s25fl127s) RESET# has an internal pull-up resistor and should be left unconnected in the host system if not used.

- find a solution for spikes on current measurement analog input.

EPS v0.2 bugs and things to improve

- wrong footprint of MSP430G… ! verify size. also: not very available. eventually change for a similar device.

- 920k precision resistor does not exist as 603. change to 100k + 820k in series (2x).

- footprint for 100mH too small

EPS v0.5 bugs and things to improve

- Resistive dividers for 3.3V boost missing

- Temperature resistive divider for solar charge missing

- Assembly note: do not solder the current sense resistor going from SC_out to V_bat before testing both circuits individually, to avoid excess current drawn from solar charger.

EPS v2.0 bugs and things to improve

- label stat1 and stat2 inverted. heater top labels missing.

- use 3.3Vref of BQ as pull-up rail for stat1 and stat2

- supply INA213 from GPIO of msp430 to be able to turn it off when not used.

weather strip v2 bugs and things to improve

✔ more clearance between SCL and GND pins at BNO055

- add test pins for logic analyzer on I2C line

✔ uv sensor: use a 1.25Vref instead of GND for comaprison.

✔ uv sensor footprint was correct in v1, NOT in this verison

✔ BMP180 is obsolete. change footprint to BMP280

weather strip v3 bugs and things to improve

✔ pin INN of lightning sensor is not connected to GND on fabricated board. Already corrected in Eagle.

✔ pin VCC of BMP280 is not connected to 3V3. Already corrected in Eagle for v3.1

  • orb/pcb.txt
  • Last modified: 6 years ago
  • by raffael