Difference between revisions of "RASPI-PLUS-GVS-CFG"

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Line 80: Line 80:
 
[[File:Bplus-gpio-edited.png]]
 
[[File:Bplus-gpio-edited.png]]
  
I2C bus
+
==== I2C bus ====
GND
+
 
3.3V
+
# GND
SDA
+
# 3.3V
SCL
+
# SDA
UART I/F
+
# SCL
GND
+
 
3.3V
+
==== UART I/F ====
TxD
+
 
RxD
+
# GND
IO_4 GVS
+
# 3.3V
GND
+
# TxD
3.3V
+
# RxD
GPIO_4
+
 
IO_18 GVS
+
==== IO_4 GVS ====
GND
+
 
3.3V
+
# GND
GPIO_18
+
# 3.3V
IO_17 GVS
+
# GPIO_4
GND
+
 
3.3V
+
==== IO_18 GVS ====
GPIO_17
+
 
IO_27 GVS
+
# GND
GND
+
# 3.3V
3.3V
+
# GPIO_18
GPIO_27
+
 
IO_23 GVS
+
==== IO_17 GVS ====
 +
 
 +
# GND
 +
# 3.3V
 +
# GPIO_17
 +
 
 +
==== IO_27 GVS ====
 +
 
 +
# GND
 +
# 3.3V
 +
# GPIO_27
 +
 
 +
==== IO_23 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_23
 
GPIO_23
IO_22 GVS
+
 
 +
==== IO_22 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_22
 
GPIO_22
IO_24 GVS
+
 
 +
==== IO_24 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_24
 
GPIO_24
IO_25 GVS
+
 
 +
==== IO_25 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_25
 
GPIO_25
SPI0 (Serial Peripheral Interface)
+
==== SPI0 (Serial Peripheral Interface) ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
Line 129: Line 149:
 
SCK
 
SCK
 
CE0
 
CE0
SPI1 (Serial Peripheral Interface)
+
 
 +
==== SPI1 (Serial Peripheral Interface) ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
Line 136: Line 158:
 
SCK
 
SCK
 
CE1
 
CE1
IO_5 GVS
+
 
 +
==== IO_5 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_5
 
GPIO_5
IO_6 GVS
+
 
 +
==== IO_6 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_6
 
GPIO_6
IO_12 GVS
+
 
 +
==== IO_12 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_12
 
GPIO_12
IO_13 GVS
+
 
 +
==== IO_13 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_13
 
GPIO_13
IO_19 GVS
+
 
 +
==== IO_19 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_19
 
GPIO_19
IO_16 GVS
+
 
 +
==== IO_16 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_16
 
GPIO_16
IO_26 GVS
+
 
 +
==== IO_26 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_26
 
GPIO_26
IO_20 GVS
+
 
 +
==== IO_20 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_20
 
GPIO_20
IO_21 GVS
+
 
 +
==== IO_21 GVS ====
 +
 
 
GND
 
GND
 
3.3V
 
3.3V
 
GPIO_21
 
GPIO_21
J22 - EEPROM Address/Write Enable Header - Rev X2 Hat
+
 
 +
==== J22 - EEPROM Address/Write Enable Header - Rev X2 Hat ====
 +
 
 
Write Enable - Install header to allow writes to EEPROM
 
Write Enable - Install header to allow writes to EEPROM
 
Remove header to protect EEPROM contents from accidental writes
 
Remove header to protect EEPROM contents from accidental writes
J22 - EEPROM Address/Write Enable Header - Rev X1 Hat
+
 
 +
==== J22 - EEPROM Address/Write Enable Header - Rev X1 Hat ====
 +
 
 
RasPi-GVS-Plus-CFG-adrsel-we.png
 
RasPi-GVS-Plus-CFG-adrsel-we.png
  
Line 182: Line 226:
 
5-6 = A1 - installed = 0
 
5-6 = A1 - installed = 0
 
7-8 = A2 - installed = 0
 
7-8 = A2 - installed = 0
J23 - Voltage translator, 3V side
+
 
 +
==== J23 - Voltage translator, 3V side ====
 +
 
 
V3-1 = Bit 1
 
V3-1 = Bit 1
 
V3-2 = Bit 2
 
V3-2 = Bit 2
Line 191: Line 237:
 
V3-7 = Bit 7
 
V3-7 = Bit 7
 
V3-8 = Bit 8
 
V3-8 = Bit 8
5V Connectors
+
 
 +
=== 5V Connectors ===
 +
 
 
The following are 5V connectors.
 
The following are 5V connectors.
  

Revision as of 14:08, 24 January 2020

Tindie-mediums.png

RasPi-Plus-GVS-Cfg-X2-CCA-640px.jpg

Features

  • All Raspberry Pi I/O lines
  • 8-bit bidirectional 3.3V to 5V level translator
  • Configuration EEPROM
  • Fuses on power

Raspberry Pi I/O lines

  • All of the Raspberry Pi Model B+ I/O connections are brought to GVS connectors. This is:
    • (17) GPIO lines on GVS connectors
    • (2) SPI interfaces
    • (1) UART interface
    • (1) I2C interface

Level translators

  • The BBB-GVS board use an 8-bit wide Texas Instrument TXS0108 voltage translator to convert up to 8 of the 3.3V I/O lines to 5V I/O levels.

Voltage Translators Features

  • No Direction-Control Signal Needed
  • Max Data Rates
    • 60 Mbps (Push Pull)
    • 2 Mbps (Open Drain)
  • 1.2 V to 3.6 V on A Port and 1.65 V to 5.5 V on
  • B Port (VCCA ≤ VCCB)
  • No Power-Supply Sequencing Required –
    • Either VCCA or VCCB Can Be Ramped First
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22 (A Port)
    • 2000-V Human-Body Model (A114-B)
    • 150-V Machine Model (A115-A)
    • 1000-V Charged-Device Model (C101)
  • IEC 61000-4-2 ESD (B Port)
    • ±6-kV Air-Gap Discharge
    • ±8-kV Contact Discharge

Voltage Translators Architecture

Datasheet

The TXS0108E can be used in level-translation applications for interfacing devices or systems operating at different interface voltages with one another. The TXS0108E is ideal for use in applications where an open-drain driver is connected to the data I/Os. The TXS0108E can also be used in applications where a push-pull driver is connected to the data I/Os, but the TXB0104 might be a better option for such push-pull applications. The TXS0108E device is a semi-buffered auto-direction-sensing voltage translator design is optimized for translation applications (e.g. MMC Card Interfaces) that require the system to start out in a low-speed open-drain mode and then switch to a higher speed push-pull mode.

TXS0108Arch.PNG

To address these application requirements, a semi-buffered architecture design is used and is illustrated above (see Figure 1). Edge-rate accelerator circuitry (for both the high-to-low and low-to-high edges), a High-Ron n-channel pass-gate transistor (on the order of 300 Ω to 500 Ω) and pull-up resistors (to provide DC-bias and drive capabilities) are included to realize this solution. A direction-control signal (to control the direction of data flow from A to B or from B to A) is not needed. The resulting implementation supports both low-speed open-drain operation as well as high-speed push-pull operation.

When transmitting data from A to B ports, during a rising edge the One-Shot (OS3) turns on the PMOS transistor (P2) for a short-duration and this speeds up the low-to-high transition. Similarly, during a falling edge, when transmitting data from A to B, the One-Shot (OS4) turns on NMOS transistor (N2) for a short-duration and this speeds up the high-to-low transition. The B-port edge-rate accelerator consists of one-shots OS3 and OS4, Transistors P2 and N2 and serves to rapidly force the B port high or low when a corresponding transition is detected on the A port.

When transmitting data from B to A ports, during a rising edge the One-Shot (OS1) turns on the PMOS transistor (P1) for a short-duration and this speeds up the low-to-high transition. Similarly, during a falling edge, when transmitting data from B to A, the One-Shot (OS2) turns on NMOS transistor (N1) for a short-duration and this speeds up the high-to-low transition. The A-port edge-rate accelerator consists of one-shots OS1 and OS2, Transistors P1 and N1 components and form the edge-rate accelerator and serves to rapidly force the A port high or low when a corresponding transition is detected on the B port.

Fuses

  • The board has Resettable fuses on the 3.3V and 5V from the Raspberry Pi.
  • These fuses protect your Raspberry Pi from overloads.
  • These fuses are 1/2 Amp PTC fuses.
  • PTC fuses have certain advantages (they are self healing) and disadvantages (they are not like a wire fuse which acts like a switch).
  • If you trust your wiring you may choose to solder a wire over the fuse.
    • Care should be taken when doing so.

Configuration EEPROM

3.3V Connectors

The following are all 3.3VDC connections.

Raspberry Pi B Plus GPIO Connector

  • J8 on the Pi.

File:Bplus-gpio-edited.png

I2C bus

  1. GND
  2. 3.3V
  3. SDA
  4. SCL

UART I/F

  1. GND
  2. 3.3V
  3. TxD
  4. RxD

IO_4 GVS

  1. GND
  2. 3.3V
  3. GPIO_4

IO_18 GVS

  1. GND
  2. 3.3V
  3. GPIO_18

IO_17 GVS

  1. GND
  2. 3.3V
  3. GPIO_17

IO_27 GVS

  1. GND
  2. 3.3V
  3. GPIO_27

IO_23 GVS

GND 3.3V GPIO_23

IO_22 GVS

GND 3.3V GPIO_22

IO_24 GVS

GND 3.3V GPIO_24

IO_25 GVS

GND 3.3V GPIO_25

SPI0 (Serial Peripheral Interface)

GND 3.3V MOSI MISO SCK CE0

SPI1 (Serial Peripheral Interface)

GND 3.3V MOSI MISO SCK CE1

IO_5 GVS

GND 3.3V GPIO_5

IO_6 GVS

GND 3.3V GPIO_6

IO_12 GVS

GND 3.3V GPIO_12

IO_13 GVS

GND 3.3V GPIO_13

IO_19 GVS

GND 3.3V GPIO_19

IO_16 GVS

GND 3.3V GPIO_16

IO_26 GVS

GND 3.3V GPIO_26

IO_20 GVS

GND 3.3V GPIO_20

IO_21 GVS

GND 3.3V GPIO_21

J22 - EEPROM Address/Write Enable Header - Rev X2 Hat

Write Enable - Install header to allow writes to EEPROM Remove header to protect EEPROM contents from accidental writes

J22 - EEPROM Address/Write Enable Header - Rev X1 Hat

RasPi-GVS-Plus-CFG-adrsel-we.png

1-2 = Write Enable - install to allow writes 3-4 = A0 - installed = 0 5-6 = A1 - installed = 0 7-8 = A2 - installed = 0

J23 - Voltage translator, 3V side

V3-1 = Bit 1 V3-2 = Bit 2 V3-3 = Bit 3 V3-4 = Bit 4 V3-5 = Bit 5 V3-6 = Bit 6 V3-7 = Bit 7 V3-8 = Bit 8

5V Connectors

The following are 5V connectors.

V5-1 - GVS connector, 5V side Ground +5V Bit1 V5-2 - GVS connector, 5V side Ground +5V Bit2 V5-3 - GVS connector, 5V side Ground +5V Bit3 V5-4 - GVS connector, 5V side Ground +5V Bit4 V5-5 - GVS connector, 5V side Ground +5V Bit5 V5-6 - GVS connector, 5V side Ground +5V Bit6 V5-7 - GVS connector, 5V side Ground +5V Bit7 V5-8 - GVS connector, 5V side Ground +5V Bit8 Layout - Rev X2 Kickstarter Edition

RasPi-Plus-GVS-CFG-X2-mechs.png

Layout - Rev X1 Prototype Edition - Not available on Kickstarter

RasPi-GVS-Plus-CFG-mechs.png

Assembly Sheet RasPi-Plus-GVS-Cfg Configuration Sheet - Rev X2 Design Validation Testing - Rev X1 Board RASPI-PLUS-GVS-CFG DVT

Factory Acceptance Tests (FAT) Hardware FAT requires the following:

Raspberry Pi Model B+ or equivalent (RasPi) Power supply for Raspberry Pi (5V at 1 Amp min) with Micro USB connector Monitor, Keyboard or Ethernet cable and laptop running puTTY Test Software loaded onto RasPi (1) LED-Test card + side of LEDs to V5-2 thru 8 - side of LEDs to GND at +5V side Jumpers (female-to-female) Daisy-chain cables 8-pin, 1-2, 3-4, 5-6, 7-8 @ IO6-IO21 (2) 4-pin, 1 open, 2 open, 3-4 @ J1, J2 Single female to female @ SPI1-IO5 6 pin, 1 open, 2 open, 3-4, 5-6 @ SPI0 (3) 8-pin female-female jumper cables 1 jumper +3.3V side to IO4-IO25 2 (to LED-Test card) Unit Under Test (UUT) RPP-GVS-CFG-X2-fastTest-640px.jpg

Preliminary Install UUT onto RasPi Install Cables Power up card Log into RasPi GVS Connector - Daisy-chain Tests On RasPi console: pi raspberry

cd ~/RasPi/RasPi-Plus-GVS-Cfg/ sudo python fastTests.py

Result should be Daisy test passed LEDs should cycle I2C cd ~/RasPi/RasPi-Plus-GVS-Cfg/eeprom/ sudo ./eep2flash.sh -w -t=24c32 -f=eepcfg.eep sudo ./eep2flash.sh -r -t=24c32 -f=myeep.eep rm stuff.eep ./eepdump myeep.eep stuff.eep more stuff.eep | grep vendor

Verify:

  1. ---------- Dump generated by eepdump handling format version 0x01 ----------
  2. --Header--
  3. signature=0x69502d52
  4. version=0x01
  5. reserved=0
  6. numatoms=2
  7. eeplen=117
  8. ----------


  1. Start of atom #0 of type 0x0001 and length 57
  2. Vendor info

product_uuid 3ea7c89f-353e-4633-bd6c-2572996f277b product_id 0x0004 product_ver 0x0001 vendor "land-boards.com" # length=15 product "RASPI-PLUS-GVS-CFG" # length=18

  1. End of atom. CRC16=0x437a


  1. Start of atom #1 of type 0x0002 and length 32
  2. GPIO map info

gpio_drive 0 gpio_slew 0 gpio_hysteresis 0 back_power 0

  1. GPIO FUNCTION PULL
  2. ---- -------- ----
  3. End of atom. CRC16=0x6eed

Combined copy/paste cd ~/RasPi/RasPi-Plus-GVS-Cfg/eeprom/ sudo ./eep2flash.sh -w -t=24c32 -f=eepcfg.eep sudo ./eep2flash.sh -r -t=24c32 -f=myeep.eep rm stuff.eep ./eepdump myeep.eep stuff.eep diff stuff.eep eepcomp.eep cd ~/RasPi/RasPi-Plus-GVS-Cfg/ sudo python fastTests.py== Schematic ==

RasPi-GVS-Plus-CFG_Rev_X3_Schematic.pdf Schematic

Drivers/Example Code

Assembly Sheet