SPI-POTX2
Contents
Features
- Dual Digital potentiometer
- MCP4231 Dual Digital Pot
- 7-bit: 128 Resistors (129 Steps)
- Zero Scale to Full Scale Wiper operation
- 10K
- Other resistances optional: 5K, 50K, 100K
- Power on reset to half wiper value
- SPI Interface
- SPI Serial Interface (10 MHz, modes 0,0 & 1,1)
- High-Speed Read/Writes to wiper register
- 10 MHz (max SPI speed)
- 2.7V to 5.5V
- Daisy-chain SPI connector
- Slave Select (SS) should be star connected
- 49x49mm form factor
- (4) #4-40 mounting holes
Connectors
J1, J3 - SPI connector
- MISO
- +V
- SCK
- MOSI
- SS
- GND
J2 - SPI Connector
- Matches Arduino SPI connector pinout
- MISO
- +V
- SCK
- MOSI
- SS
- GND
POT0, POT1
- GND
- B SIDE
- WIPER
- A SIDE
- +V
Driver Software
- SPI-POT-X2 GitHub Arduino Example Code
- Creates triangle wave output on both outputs
Factory Test Procedure
- Test SPI-POTX2 card on RPI_PSOC5 Test Station
Hardware Setup
[[FILE:]]
- RPI_PSOC5
- Raspberry Pi CPU Clone
- RPI-SPI8
- 8-channel SPI multiplexer
- 2x6 cable
- CE (SS)
- MOSI
- MISO
- SCK
- VCC
- GND
Run Tests
- Run puTTY
- Find COM Port in Device Manager
- 115,200 baud
- RTS/CTS flow control
- Hit ENTER to see menu
Land Boards, LLC - RPi Card Test Station 1 - Select RPP-UIO-16 Card 2 - Select RPPSOC Card 3 - Select RASPI-PLUS-GVS-CFG Card 4 - Select RASPI-GVS Card 5 - Select RASPI-PLUS-GVS Card 6 - Select RPI-I2C-HUB Card 7 - Select RPI-SPI8 Card R - Read EEPROM W - Write EEPROM B - Bounce LED across Card GPIOs T - Test Card D - Debug Card ? - Print this menu
- Select RPI-SPI8 Card by entering 7[ENTER]
7 Selected RPI-SPI8 card
Create Sawtooth Output
- Enter B[ENTER] - Create ramped output
B Blinking the RPI-SPI8 Card LEDs, please wait
- Bounces LEDs off across the LEDs
- 8 CE signals go low one at a time
- MOSI, MISO, SCK cycles one on at time
- Ramped output
Test Software
- Runs on RPI_PSOC5
- GitHub repo
- Test_RPI_SPI8.c - Bounce LED across LED-TEST-2 card
- Runs on RPI_PSOC5
- Uses RPI_SPI8
- GitHub repo
- Test_RPI_SPI8.c - Test with SPI-POTX2 card
