This page contains the details on the new SCuM Eval Boards |
SCuM
GPIO headers
Dimensions smaller than 40 mm x 50 mm (not sure about lower limit yet)
Standoffs
SCuM
All SCuM pads have either a pin header or a via to be used as a testpoint nearby with the exception of aLOAD, aSCANIN, and aSCSEL whose testpoints can be found in the bottom right corner of the board near the antenna section right at the corresponding level shifter.
Development region
8 rows of 4 connected pads
Mounting holes for standoffs
Pins
Two different boards for Teensy and nRF
Teensy 3.6 (names as referenced here: https://github.com/PisterLab/scum-test-code/blob/master/scm_v3c/teensy_uC_programmer/teensy_uC_programmer.ino https://github.com/PisterLab/scum-test-code/blob/master/scm_v3c/teensy_uC_programmer/teensy_uC_programmer.ino).
GND
Vin
asc_source_select (VBAT for SCuM/3.3V for Teensy)
aPHI (VBAT/3.3V)
aPHIb (VBAT/3.3V)
aLOAD (VBAT/3.3V)
aSCANIN (VBAT/3.3V)
aSCANOUT (VBAT/3.3V)
clock_out (VBAT/3.3V)
hReset (VBAT/3.3V)
sReset (VBAT/3.3V)
GPIO0 (VDDIO)
GPIO1 (VDDIO)
GPIO2 (VDDIO)
GPIO3 (VDDIO)
RsRx (VDDIO)
RsTx (VDDIO)
clkPin (3WB) (VBAT/3.3V)
enablePin (3WB) (VBAT/3.3V)
dataPin (3WB) (VBAT/3.3V)
nRF
To be completed once pins for programming are finalized
Remaining GPIO pins not used for Teensy/nRF
Antenna
IMU
ICM-20948
SPI
ADO
GPIO12
SCLK
GPIO14
SDI
GPIO13
I2C
SDA
GPIO13
SCL
GPIO14
SDO
GPIO12
Chip Select
GPIO15
Jumper to use pullup resistors
J10
Voltage Domains
Vin pin
3.3V
Can take input from Teensy, nRF, or another source
USB-UART based 3.3V
VBAT
1.5V
External Pin
DC-DC converter from Vin to set VBAT to 1.5V
VDDIO
External Pin
Vin
VBAT
1.8V
VDDD
External Pin
VBAT
DC-DC converter from Vin to set VDDD to 1.0V
UART
USB
Teensy/nRF
Size
Teensy
1.543 in x 2.738 in
nRF
Store project on PisterLab GitHub https://github.com/PisterLab/scum-dev-board
Earlier PCB’s are on Box. Files can be viewed using Altium Viewer without downloading anything https://www.altium.com/viewer/
Components:
Schematic:
Layout:
Remove resistors on IMU (the two resistors are only put there is we are trying to configure the board into I2C mode, but we are using the default SPI mode for which the resistors should not be connected)
Easy way to tie GPIO 1 to GPIO 8 and a way to tie GPIO1 to GPIO9 with pin header. This is useful for lighthouse localization.
There is a discrepancy between the bond diagram for ALWAYSON_LDO_OUT for https://github.com/PisterLab/scum-dev-board/blob/quikpak_ll/qfn_info/bigBoard_bond_diagram.pdf and https://github.com/PisterLab/scum-dev-board/blob/master/scum3c_devboard_large/Images/scum3C%20Large%20Board%20bond%20diagram.png. Both boards have this discrepancy and should be modified to match the first link.
Add the missing SCuM pins to schematic (mark as no connections) just for bookkeeping
Currently SDO pin on IMU is connected to GPIO12 and SDI pin on IMU is connected to GPIO13. It would be nice to have SDO pin on IMU connected to GPIO13 instead and SDI pin of IMU connected to GPIO12. This is to match the hardware configuration with the code Brian wrote before to maintain as much consistency between boards as possible so code can be reused across all of them.
Request from DB: “it would be nice to have plated vias on as many of the SCuM pins as possible so we can fully wirebond and then thread a 30 AWG wire in if we need to splice something on“
Pin layout: https://docs.google.com/drawings/d/1l1O0RtISmslJsic9txYNfCFIynfG-745T3hjRpNIH5w/edit?usp=sharing
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Pin layout: https://docs.google.com/drawings/d/1-NSjz1xg-1bFSp3lY8e1M7UuoZM1Tlf1_K2JZVS5FTk/edit?usp=sharing
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Small board
Don’t put R1 and R2 on the board since we don’t want to configure IMU into I2C mode
Big board
For first iteration on board, don’t put R5 and R6 since we don’t want IMU in I2C mode
Don’t put C1 and L4 since we don’t want to use the chip antenna (at least not yet). Additionally the chip antenna shouldn’t be added.
The through hole antenna will be solder on after the surface mount components (Austin will do this)
We moved to through hole USB port. This should still be soldered on with the solder paste and then I (Austin) can solder the final connections.
The USB port has a new capacitor on it that doesn’t have a label…. I believe 0.1uF should be fine to put there