Difference between revisions of "RASPI-PLUS-GVS"

Latest revision as of 15:07, 24 January 2020

3.3V/5V Sensor Conn Card for Raspberry Pi A+/B+

Board Design This board is modeled on the Arduino Sensor Shields, also known as GVS shields. Arduino Sensor Shields bring out the pins of the Arduino to GVS (set of Ground, Voltage and Signal) pins.

Unfortunately, the Raspberry Pi can't work with the same GVS cards as the Arduino since the Raspberry Pi has 3.3V I/O.

The RASPI-PLUS-GVS card allows the Raspberry Pi to communicate with the same 5V sensors by performing voltage translation from the 3.3V of the Raspberry Pi to 5V.

Features

3.3V to 5V bidirectional voltage translators on Raspberry Pi GPIO lines
(7) 5V GPIO lines on GVS connectors
(2) 5V SPI interfaces (5 lines which can be )
(1) 5V UART interface
(1) 5V I2C interface
GPIO_4 enables/disables the voltage translators
(9) 3.3V GPIO interfaces
Optional Power Supply which can power the GVS connectors
Raspberry Pi Model A+/B+ card form factor

Voltage Translators

The RASPI-PLUS-GVS board uses Texas Instrument TXS0108 voltage translators.

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.

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.

Power Supply

The RASPI-PLUS-GVS offers flexible power supply options. The 5V for the GVS Connnectors and translators can come either from the Raspberry Pi or from the 5V power supply.

A three pin header and jumpers are used to select the voltage source(s).

Installing a jumper from pins 2 to 3 allow the Raspberry Pi to power the GVC connectors and voltage translators.

Installing a jumper from 3 to 4 powers the GVS connections from the 5V power supply.

Resettable Fuses

The board has two Resettable Fuses. One of the fuses connects to the 5V lines to/from the Raspberry Pi. The other fuse is on the output of the on-board regulator. The 3.3V has no fuses.

Connectors

Raspberry Pi B Plus GPIO Connector Bplus-gpio-edited.png

J1 - 5V I2C bus

GND
5V
SDA
SCL

J2 - 5V UART I/F

GND
5V
TX
Rx

J3 - 5V IO_18 GVS

GND
5V
GPIO_18

J4 - 5V IO_17 GVS

GND
5V
GPIO_17

J5 - 5V IO_27 GVS

GND
5V
GPIO_27

J6 - 5V IO_23 GVS

GND
5V
GPIO_23

J7 - 5V IO_22 GVS

GND
5V
GPIO_22

J8 - 5V IO_24 GVS

GND
5V
GPIO_24

J9 - 5V IO_25 GVS

GND
5V
GPIO_25

J10 - 5V SPI0 (Serial Peripheral Interface)

GND
5V
MOSI
MISO
SCK
CE0

J11 - 5V SPI1 (Serial Peripheral Interface)

GND
5V
MOSI
MISO
SCK
CE1

J12 - 3.3V IO_5 GVS

GND
5V
GPIO_5

J13 - 3.3V IO_6 GVS

GND
5V
GPIO_6

J14 - 3.3V IO_13 GVS

GND
5V
GPIO_13

J15 - 3.3V IO_19 GVS

GND
5V
GPIO_19

J16 - 3.3V IO_26 GVS

GND
5V
GPIO_26

J17 - 3.3V IO_21 GVS

GND
5V
GPIO_21

J18 - 3.3V IO_12 GVS

GND
5V
GPIO_12

J19 - 3.3V IO_16 GVS

GND
5V
GPIO_16

J20 - 3.3V IO_20 GVS

GND
5V
GPIO_20

2.1mm DC Power Jack - 7-9 VDC

Shell - Ground
Center - Power (7-9 VDC)

J21 - Power Select Jumper(s)

1-2 = Power 5V GVS from regulator
2-3 = Power 5V GVS from Raspberry Pi

Board Layout

RASPI-PLUS-GVS Factory Acceptance Test

Connect LED-Test or LED-TEST-2 card to GPS lines (all except UART lines)
Load test software from GitHub
Enter

cd ~/RasPi/RasPi-Plus-GVS
sudo python ./blinkLEDs.py

LED Order

	blinkLED(J12)
	blinkLED(J13)
	blinkLED(J14)
	blinkLED(J15)
	blinkLED(J16)
	blinkLED(J17)
	blinkLED(J18)
	blinkLED(J19)
	blinkLED(J20)
	blinkLED(J3)
	blinkLED(J4)
	blinkLED(J5)
	blinkLED(J6)
	blinkLED(J7)
	blinkLED(J8)
	blinkLED(J9)
	blinkLED(J1_3)
	blinkLED(J1_4)
	blinkLED(J2_3)
	blinkLED(J2_4)
	blinkLED(J10_3)
	blinkLED(J10_4)
	blinkLED(J10_5)
	blinkLED(J10_6)
	blinkLED(J11_6)

Drivers/Example Code

Github repo - Driver code

Assembly Sheet

RASPI-PLUS-GVS Assembly Sheet

@@ Line 14: / Line 14: @@
 The RASPI-PLUS-GVS card allows the Raspberry Pi to communicate with the same 5V sensors by performing voltage translation from the 3.3V of the Raspberry Pi to 5V.
-RasPi-Plus-GVS-DC-CCA-02x640.jpg
+== Features ==
-Features
+* 3.3V to 5V bidirectional voltage translators on Raspberry Pi GPIO lines
-.3V to 5V bidirectional voltage translators on Raspberry Pi GPIO lines
+* (7) 5V GPIO lines on GVS connectors
-(7) 5V GPIO lines on GVS connectors
+* (2) 5V SPI interfaces (5 lines which can be )
-(2) 5V SPI interfaces (5 lines which can be )
+* (1) 5V UART interface
-(1) 5V UART interface
+* (1) 5V I2C interface
-(1) 5V I2C interface
+* GPIO_4 enables/disables the voltage translators
-GPIO_4 enables/disables the voltage translators
+* (9) 3.3V GPIO interfaces
-(9) 3.3V GPIO interfaces
+* Optional Power Supply which can power the GVS connectors
-Optional Power Supply which can power the GVS connectors
+* Raspberry Pi Model A+/B+ card form factor
-Raspberry Pi Model A+/B+ card form factor
-Voltage Translators
-The RASPI-PLUS-GVS board uses Texas Instrument TXS0108 voltage translators.
-Voltage Translators Features
+=== Voltage Translators ===
-No Direction-Control Signal Needed
-Max Data Rates
+The RASPI-PLUS-GVS board uses Texas Instrument [http://www.ti.com/lit/ds/symlink/txs0108e.pdf TXS0108] voltage translators.
-Mbps (Push Pull)
-Mbps (Open Drain)
+=== Voltage Translators Features ===
-.2 V to 3.6 V on A Port and 1.65 V to 5.5 V on
-B Port (VCCA ≤ VCCB)
+* No Direction-Control Signal Needed
-No Power-Supply Sequencing Required –
+* Max Data Rates
-Either VCCA or VCCB Can Be Ramped First
+** 60 Mbps (Push Pull)
-Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
+* 2 Mbps (Open Drain)
-ESD Protection Exceeds JESD 22 (A Port)
+* 1.2 V to 3.6 V on A Port and 1.65 V to 5.5 V on
--V Human-Body Model (A114-B)
+* B Port (VCCA ≤ VCCB)
--V Machine Model (A115-A)
+* No Power-Supply Sequencing Required –
--V Charged-Device Model (C101)
+* Either VCCA or VCCB Can Be Ramped First
-IEC 61000-4-2 ESD (B Port)
+* Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
-±6-kV Air-Gap Discharge
+* ESD Protection Exceeds JESD 22 (A Port)
-±8-kV Contact Discharge
+** 2000-V Human-Body Model (A114-B)
-Voltage Translators Architecture
+** 150-V Machine Model (A115-A)
-Datasheet
+** 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 ====
+[http://www.ti.com/lit/ds/symlink/txs0108e.pdf 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
+[[File: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.
@@ Line 59: / Line 63: @@
 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.
-Power Supply
+== Power Supply ==
 The RASPI-PLUS-GVS offers flexible power supply options. The 5V for the GVS Connnectors and translators can come either from the Raspberry Pi or from the 5V power supply.
@@ Line 68: / Line 73: @@
 Installing a jumper from 3 to 4 powers the GVS connections from the 5V power supply.
-Resettable Fuses
+== Resettable Fuses ==
 The board has two Resettable Fuses. One of the fuses connects to the 5V lines to/from the Raspberry Pi. The other fuse is on the output of the on-board regulator. The 3.3V has no fuses.
-Connectors
+== Connectors ==
 Raspberry Pi B Plus GPIO Connector
 Bplus-gpio-edited.png
-J1 - 5V I2C bus
+=== J1 - 5V I2C bus ===
-GND
-V
+# GND
-SDA
+# 5V
-SCL
+# SDA
-J2 - 5V UART I/F
+# SCL
-GND
-V
+=== J2 - 5V UART I/F ===
-TX
-Rx
+# GND
-J3 - 5V IO_18 GVS
+# 5V
-GND
+# TX
-V
+# Rx
-GPIO_18
-J4 - 5V IO_17 GVS
+=== J3 - 5V IO_18 GVS ===
-GND
-V
+# GND
-GPIO_17
+# 5V
-J5 - 5V IO_27 GVS
+# GPIO_18
-GND
-V
+=== J4 - 5V IO_17 GVS ===
-GPIO_27
-J6 - 5V IO_23 GVS
+# GND
-GND
+# 5V
-V
+# GPIO_17
-GPIO_23
-J7 - 5V IO_22 GVS
+=== J5 - 5V IO_27 GVS ===
-GND
-V
+# GND
-GPIO_22
+# 5V
-J8 - 5V IO_24 GVS
+# GPIO_27
-GND
-V
+=== J6 - 5V IO_23 GVS ===
-GPIO_24
-J9 - 5V IO_25 GVS
+# GND
-GND
+# 5V
-V
+# GPIO_23
-GPIO_25
-J10 - 5V SPI0 (Serial Peripheral Interface)
+=== J7 - 5V IO_22 GVS ===
-GND
-V
+# GND
-MOSI
+# 5V
-MISO
+# GPIO_22
-SCK
-CE0
+=== J8 - 5V IO_24 GVS ===
-J11 - 5V SPI1 (Serial Peripheral Interface)
-GND
-V
-MOSI
-MISO
-SCK
-CE1
-J12 - 3.3V IO_5 GVS
-GND
-.3V
-GPIO_5
-J13 - 3.3V IO_6 GVS
-GND
-.3V
-GPIO_6
-J14 - 3.3V IO_13 GVS
-GND
-.3V
-GPIO_13
-J15 - 3.3V IO_19 GVS
-GND
-.3V
-GPIO_19
-J16 - 3.3V IO_26 GVS
-GND
-.3V
-GPIO_26
-J17 - 3.3V IO_21 GVS
-GND
-.3V
-GPIO_21
-J18 - 3.3V IO_12 GVS
-GND
-.3V
-GPIO_12
-J19 - 3.3V IO_16 GVS
-GND
-.3V
-GPIO_16
-J20 - 3.3V IO_20 GVS
-GND
-.3V
-GPIO_20
-.1mm DC Power Jack - 7-9 VDC
-Shell - Ground
-Center - Power (7-9 VDC)
-J21 - Power Select Jumper(s)
--2 = Power 5V GVS from regulator
--3 = Power 5V GVS from Raspberry Pi
-Board Layout
-RasPi-Plus-GVS-X2-PWB-bw.png
-RASPI-PLUS-GVS Assembly Sheet
+# GND
-RasPi-Plus-GVS Configuration Sheet
+# 5V
+# GPIO_24
-RASPI-PLUS-GVS Factory Acceptance Test
+=== J9 - 5V IO_25 GVS ===
-Connect LED-Test or LED-TEST-2 card to GPS lines (all except UART lines)
-Load test software from GitHub
+# GND
-Enter
+# 5V
+# GPIO_25
+=== J10 - 5V SPI0 (Serial Peripheral Interface) ===
+# GND
+# 5V
+# MOSI
+# MISO
+# SCK
+# CE0
+=== J11 - 5V SPI1 (Serial Peripheral Interface) ===
+# GND
+# 5V
+# MOSI
+# MISO
+# SCK
+# CE1
+=== J12 - 3.3V IO_5 GVS ===
+# GND
+# 5V
+# GPIO_5
+=== J13 - 3.3V IO_6 GVS ===
+# GND
+# 5V
+# GPIO_6
+=== J14 - 3.3V IO_13 GVS ===
+# GND
+# 5V
+# GPIO_13
+=== J15 - 3.3V IO_19 GVS ===
+# GND
+# 5V
+# GPIO_19
+=== J16 - 3.3V IO_26 GVS ===
+# GND
+# 5V
+# GPIO_26
+=== J17 - 3.3V IO_21 GVS ===
+# GND
+# 5V
+# GPIO_21
+=== J18 - 3.3V IO_12 GVS ===
+# GND
+# 5V
+# GPIO_12
+=== J19 - 3.3V IO_16 GVS ===
+# GND
+# 5V
+# GPIO_16
+=== J20 - 3.3V IO_20 GVS ===
+# GND
+# 5V
+# GPIO_20
+=== 2.1mm DC Power Jack - 7-9 VDC ===
+* Shell - Ground
+* Center - Power (7-9 VDC)
+=== J21 - Power Select Jumper(s) ===
+* 1-2 = Power 5V GVS from regulator
+* 2-3 = Power 5V GVS from Raspberry Pi
+== Board Layout ==
+[[File:RasPi-Plus-GVS-X2-PWB-bw.png]]
+== RASPI-PLUS-GVS Factory Acceptance Test ==
+* Connect LED-Test or LED-TEST-2 card to GPS lines (all except UART lines)
+* Load test software from GitHub
+* Enter
+<pre>
 cd ~/RasPi/RasPi-Plus-GVS
 sudo python ./blinkLEDs.py
-LED Order
+</pre>
+* LED Order
+<pre>
 	blinkLED(J12)
 	blinkLED(J13)
@@ Line 208: / Line 261: @@
 	blinkLED(J10_6)
 	blinkLED(J11_6)
+</pre>
-== Why did you make it? ==
-One of the things which you discover early on when you try to hook up external devices is that the Raspberry Pi runs at 3.3V on the I/O pins. Unfortunately, most of the parts that you want to connect to your Pi run at 5V. The way people solve that problem is to buy a prototyping card and a voltage translation breakout card and then wire the signals up by hand. That's a lot of work and not very flexible for making changes. It's also not a very stable solution. It would be much easier if that wiring was done on the a card which connects up to the Pi.
-== What makes it special? ==
-This hat takes all of the I/O lines from the Raspberry Pi and brings them out to GVS (Ground/Voltage/Signal) connectors. GPIO lines get their own connectors with their own power and ground. Signals that are part of a function like I2C, UART, and SPI signals get put together onto connectors but still get power and ground on those connectors. If, for instance, you want to connect up to a 5V LCD which runs SPI you would just wire it to one of the two SPI connectors.
-== Schematic ==
-* [http://land-boards.com/RasPi-Plus-GVS/Raspi-Plus-GVS_Rev_X2_Schematic.pdf RASPI-PLUS-GVS Schematic]
 == Drivers/Example Code ==