1. 14 May, 2018 1 commit
  2. 12 May, 2018 3 commits
  3. 11 May, 2018 2 commits
  4. 10 May, 2018 2 commits
  5. 09 May, 2018 1 commit
  6. 08 May, 2018 1 commit
  7. 07 May, 2018 1 commit
  8. 05 May, 2018 1 commit
  9. 04 May, 2018 2 commits
  10. 02 May, 2018 2 commits
  11. 30 Apr, 2018 1 commit
  12. 27 Apr, 2018 2 commits
  13. 25 Apr, 2018 2 commits
    • Eric Kuzmenko's avatar
      Use the main 18650 battery for the RTC (instead of a coin-cell), include... · 1163b3eb
      Eric Kuzmenko authored
      Use the main 18650 battery for the RTC (instead of a coin-cell), include information about which battery has been narrowed down to be the best option (NCR18650BD), remove 2K EEPROM used for the board ID (MAC address) since it won't be used
      1163b3eb
    • Eric Kuzmenko's avatar
      Have the charge controller IC handle the USB-C DRP PD switch mechanism, notes... · aee37d2c
      Eric Kuzmenko authored
      Have the charge controller IC handle the USB-C DRP PD switch mechanism, notes added on what procedure is required to operate as sink/source and how to swap between these roles
      
      The mainline kernel's TCPM implementation needs to be used in conjunction with the charge controller IC's interface. For example, if the TCPC (PTN5110HQ CC controller) has the USB configured as a sink role then the TCPM (i.MX8M) would read out the CC_STATUS and POWER_STATUS registers of the CC controller IC to know this is the case, and then it (i.MX8M) would configure the charge controller IC accordingly (sink current from VBUS).
      
      Both the CC controller and charge controller's open-drain output interrupt pins are tied together, which means if either of them pull the line low then the i.MX8M needs to check both of their fault registers to determine if a fault has occured on either chip. If the INT pin wasn't pulled low due to a fault then a status update event from either chip may have triggered it, which needs to be determined, as well as the corresponding action taken. These INT pins may need to be separated if the software side is too complex, so long as there's a spare interrupt pins available.
      
      Fast swap is not supported, and is not a requirement.
      aee37d2c
  14. 24 Apr, 2018 1 commit
  15. 20 Apr, 2018 2 commits
    • Eric Kuzmenko's avatar
      Replace instances of VSYS with VBAT to remove redundancy · 0152cc9a
      Eric Kuzmenko authored
      In the case where VBAT can drop below 3.3V then it may be required to use a buck-boost in place of the existing buck converter for the 3.3V rail; may need some testing. Using the +5V rail as an input would also work but would introduce additional losses. According to several sources, when a 18650 Li-ion reaches 3.3V it is practically depleted anyway. When the feedback voltage drops below the internal reference voltage the buck converter will be in its "low dropout operation" with a duty cycle of 100%, so the output voltage should closely follow the input voltage.
      0152cc9a
    • Eric Kuzmenko's avatar
      Add USB type C circuit with DRP PD capability, should sink near 2A @ 5-6.5V and source 550mA @ 5V · 3b1b0bc8
      Eric Kuzmenko authored
      Removed the reverse current protection circuit from the last commit due to the requirement changing to only 18650 battery and USB-C being possible power sources
      
      Next thing to add is the charging circuit when the USB-C is in sink mode/role
      3b1b0bc8
  16. 19 Apr, 2018 2 commits
  17. 18 Apr, 2018 3 commits
  18. 17 Apr, 2018 1 commit
  19. 16 Apr, 2018 4 commits
    • Eric Kuzmenko's avatar
      Rename project based on the EmCraft SoM · 710f9f46
      Eric Kuzmenko authored
      710f9f46
    • Eric Kuzmenko's avatar
      Add logic level shifter for WWAN PCM interface, assign CONFIG_0 to GPIO3_IO20,... · d488a636
      Eric Kuzmenko authored
      Add logic level shifter for WWAN PCM interface, assign CONFIG_0 to GPIO3_IO20, use SAI6 for WWAN PCM since the baseband modem can be either master or slave (e.g. SIM7100 is always master)
      d488a636
    • Eric Kuzmenko's avatar
      Bring out M.2 signals to the main sheet and attach WoWWAN and RESET · 631374e7
      Eric Kuzmenko authored
      Add notes regarding the WWAN M.2's USB interface. The Emcraft SoM has NAND_CE3_B available for the DISABLE pin. Still need to select which pin will be used for CONFIG_1.
      631374e7
    • Eric Kuzmenko's avatar
      Add 1.8V<->3.3V logic level shifter (NTS0102) for the WWAN M.2 slot and... · edda2c0b
      Eric Kuzmenko authored
      Add 1.8V<->3.3V logic level shifter (NTS0102) for the WWAN M.2 slot and connect it to the i.MX8M's UART3
      
      The NTS0102 explicitly lists UART as one of its applications, and contains internal 10k pull-up resistors for the outputs. Whereas NTB/TXB0102 are push-pull outputs but aren't intended for UART applications due to the following (needs testing):
      "The subtlety here is that you need to be careful of the auto direction sense circuitry.  Works fine but there can be some gotchas."
      "If there is a signal integrity concern which is generally not the case for UARTs, series ~32 Ohm resistors on TX output pins can help.  For the exact resistor value you need to look at the V/I curve of the transmitter and pick the resistor value that matches the driver to the 50 Ohm Transmission line.  Layout for 50Ohm T-Lines and cables.  This will also cut down the risk of the EMI/EMC issues since any residual ringing is cutdown by IR drop in the terminator."
      edda2c0b
  20. 13 Apr, 2018 1 commit
    • Eric Kuzmenko's avatar
      Include HKS for baseband modem M.2 module · 16a997e2
      Eric Kuzmenko authored
      Low-pass filter included for switch ckt, rise and fall time should be nearly identical with the presence of a schottky diode. Since the M.2 spec calls out a >20Kohm resistor to GND on the ~FULL_CARD_POWER_OFF pin then then a voltage divider is formed between this resistor and the one to VBAT (min of ~2.2V, actually >2.4V).
      16a997e2
  21. 12 Apr, 2018 1 commit
  22. 11 Apr, 2018 1 commit
  23. 10 Apr, 2018 1 commit
  24. 09 Apr, 2018 2 commits