Digital Potentiometer SPI AD5290 and Nusbio

Overview

The Digital Potentiometer AD5290 is not a regular one.

1. It provides 2 supply modes
1. Single supply, Positive voltage
2. Dual supply, Positive voltage and negative voltage
   You need to provide the positive and negative voltage (pin 1 and 2)
2. In mode 1, the current can be between 20 and 30 Volts.
   In mode 2, the current +-10 to +- 15 volts
3. It is only available in MSOP-10

Datasheet

 

SPI

The AD5290  is an SPI chip which does not use MISO (The chip does not send information back).
Be care full, the SDO pin is used for daisy-chaining

The recommended wiring with Nusbio is a follow

GPIO 0 - CLOCK
GPIO 1 - MOSI
GPIO 2 - CS

VB.net Code

Wiring

5 Volts from the USB

In this wiring, we use the Single supply, positive 5 volts mode from Nusbio and therefore from the USB.

9 Volts from a battery

In this wiring, we use the Single supply, positive 9 volts mode from a battery.
Nusbio GPIO 0,1,2 should never be in contact with the 9 Volts from the battery.

SPI digital potentiometer AD5290Y 10k with some vb.net code

SPI digital potentiometer AD5290Y 10k with some vb.net  code and Nusbio

Video http://bit.ly/20PkDkl 


Source Code: https://github.com/madeintheusb/Nusbio.Samples/tree/master/VB/MadeInTheUSB.Nusbio.DigitalPot.AD5290.VB

USB to SPI for .NET

Overview

I started investigating the hardware architecture for Nusbio 2. With the new device I would like to achieve a transfer of at least 100 K byte /s and target 1 M byte/s.
(Update: 2017.04.02 with the FTDI FT4222 I achieved 100 Kbyte/S in I2C using a 32k byte EEPROM and 2.4 MebaByte/S using a NOR FLASH at 100Mhz)

I most likely will use a USB 2.0 to SPI chip and add a micro-controller like the ATiny84 to provide

• More GPIOs
• PWM
• ADC
• EEPROM storage

I may select a Full speed or High speed. High speed is faster, but more expensive and most likely does not exist in package SSOP-20, but rather LQFP-48 or QFN-48.

In this post, I will summarize my findings regarding the chips I tested. Obviously my end goal is to create a .NET compatible device.

USB to SPI performance

See blog: USB to SPI for .NET (performance)

Test Scenarios

1. Test1 - Transfert 32 K byte of data from EEPROM 25AA256 (support SPI 10MHz) to computer in C#.
2. Test2 - Transfert 128 K byte of data from EEPROM 25AA1024 (support SPI 10MHz) to computer in C#.

USB to SPI Chip

• MicroChip - MCP2210 Datasheet
  
• Evaluation board ADM00419 $15
• USB 2.0 Full speed
• SPI Bitrate 3 Mbps
• 128 byte buffer
• GPIO for select: 8
• Packages: 20-lead QFN, 20-lead SOIC, 20-lead SSOP
• Price: $1.98 for one
• .NET samples: Yes
• SPI Low Level Optimization: Most likely No

• Cypress - CY7C65211 Datasheet
  
• Evaluation board  CY8CKIT-049-42XX $4
• USB 2.0 Full speed
• Bitrate 3 Mhz
• 256 byte buffer
• GPIO for select: 5 
• Packages: 24-lead QFN
• Price: $2.61 for one
• .NET samples: No. C code.
• SPI Low Level Optimization: Most likely No
• Remark: Can be configured as UART, SPI or I2C

• FTDI - FT232H Datasheet
  
• Evaluation board  UM232H $20
• USB 2.0 High speed
• Bitrate 30 Mhz for SPI
• 64k byte buffer
• GPIO for select: 5
• Packages: 48-lead QFN
• Price: $4.25 for one
• .NET samples: Partially, Require C DLL.
• SPI Low Level Optimization: Yes
• Remark: Can be configured as UART, SPI, I2C, JTAG, FIFO, Bit banging.


• SILICON LABS - CP2130 Datasheet
  
• Evaluation board  CP2130EK $20
• USB 2.0 High speed
• 6.6 Mb/s for SPI (844Kbyte/S, Video)
• xx byte buffer
• GPIO for select: 11
• Packages: 24-lead QFN
• Price: $2.16 for one
• .NET samples:?
• SPI Low Level Optimization:?

Test Result

• MicroChip - MCP2210
• At the SPI Bitrate 3 Mhz (which cannot be increased)
• Downloading the 32k of  data in chunk of 32 pages of 64 bytes (2k)
• 4.559s 7.02 K byte/S
• Conclusion: Really bad performance.
• Cypress - CY7C65211 
• At the SPI Bitrate 3 Mhz  
• Downloading the 32k of  data in chunk of 16 pages of 64 bytes (1k)
• 12 K byte/S
• I asked on the Cypress forum for help - Page. So far no real help from the Indian support.
  
• FTDI - FT232H 
• At the SPI Bitrate 10 Mhz (Max supported by the EEPROM)
• Downloading the 32k of  data in chunk of 256 pages of 64 bytes (16k)
•  0.03s  1066.67 K byte/S
• Conclusion: Really very nice performance. and the FT232H can goes up to 30 Mhz.
• SILICON LABS - CP2130

More About The MCP2210

•  Kerry Wong, blogged a lot about the MCP2210 at http://www.kerrywong.com.
• In his post "Finicky MCP2210 Oscillator", John Davis added the following comment, which explain a lot.
  
  
  WARNING: According to our trouble ticket interactions with Microchip technical support, the MCP2210 is “throttled” internally with a mininum SPI inter-byte spacing of about 45uS REGARDLESS of SPI clock frequency (we got 12 MHz working on our board.) That limits the byte data rate to about 23KBytes/second max. However, the performance is still limited further by the fact that it is an HID device with a HID-limit 64KByte/second interface. Two USB 128 byte transactions of 3mS each with a wait in between are required for a transfer, so the effective data rate using full 60 byte packets works out to slightly less than 8KBytes/second (Verified with ‘scope.) THIS IS NOT A HIGH THROUGHPUT PART!

Technical Precisions About The Nusbio Device

What is Nusbio?

Nusbio is USB device that bring the following to a Windows machine and the Microsoft .NET Runtime:

Device

• Gpios

• 8GPIO pins
• 3 or 5 volts 
• Nusbio version based on the chip FT232RL can be changed between 3.3 and 5 volts (GPIO and VCC). In 2017 only the version based on the FT232RL will be sold.
• Nusbio version based on the chip FT231X only the VCC can be changed between 3.3 and 5 volts. The GPIO are always 3.3 volts.
• Modes: OUTPUT or INPUT PULL UP.
• Maximum current per GPIO pin default 4 mA .
  The Console application allows to switch from 4 to 16 mA.
  In 16 mA of current mode we noticed that the I2C protocol does not work.

 Powering devices connected to Nusbio

• The VCC output from Nusbio provides 5 or 3.3 volts and up to 500 mA of current as defined by the USB 2.0 standard.
• The VCC output can be used to power other devices connected to Nusbio.
• Some Nusbio version based on the FT231X have a fuse that will limit the consumption to 500 mA of current.
• The voltage can be changed depending on the version as follow:
• De-soldering the 5 volts connector and soldering the 3 volts connector.
• Or switch the jumper between 5 volts and 3 volts

• SPI Protocol

• Mode

• Clock MODE_CPOL0_CPHA0 supported and tested
• The other 3 modes have been implemented but not tested.

• Tested Devices

• MCP3008 - 8 DAC
• MAX7219 - 7-Segment Driver
• 25AA256 - 32k EEPROM
• 25AA1024 - 128k EEPROM
• MCP23S08 - 8 Gpio Expander 
• OLED drivers
• SD1306
• SH1106
• SPI Compatible Devices
• 74HC595 - Shift register
• APA102 RGB LED

• SPI Slave

• Number of devices on an SPI bus. Since Nusbio comes with 8 gpios, we can control 5 (8-3 (clock, miso, mosi)) SPI devices on the same bus.

• Transfert Speed

• When data in and data out communication is needed (MOSI and MISO) the maximum transfer rate is around 15 k byte/s with no optimization.
• With specific optimization for EEPROM downloading in batch of 128 pages of 64 bytes, the transfer rate can go up to 28 k byte/s.
• Generally speaking when only data out communication is needed (no MISO) the transfer rate can go up to 20 k byte/s by using the class GpioSequence rather than the class SPIEngine. The class GpioSequence offers a way to optimize the bit banging.
• Transfer speed vary depending on the SPI device and the Windows PC.
• Nusbio and the C# class SPIEngine can transfer in one USB operation multiple SPI buffer (Select + Data + UnSelect + Select + Data + UnSelect).
• Some SPI device like the OLED driver SH1106 or SSD1306, required on top of the Select pin (CS) another pin named D/C (Data or Command). Nusbio and the C# class SPIEngine can transfer in one USB operation multiple SPI buffer (Select + D/C + Data + UnSelect + Select + D/C + Data + UnSelect. (See our source code on GitHub).

• I2C Protocol

• Tested Devices:
• 24LC256 32k EEPROM
• MCP2308 - 8 Gpio Expander 
• MCP9808 - Temperature sensor
• MCP4725 - 12Bit DAC 
• HT16K33 - Matrix Driver 
• Adafruit I2C LED Matrix devices
• Transfer Speed 
• The tests were performed by downloading 32k from the I2C EEPROM 24LC256 . 
• Transfer speed around 7.5K byte/s. 
• Transfer speed vary depending on the device and the Windows PC.

• SPI and I2C Protocol Combined

  With Nusbio it is possible to control SPI and I2C devices from the same configuration. For example
  
  
  
  • GPIO 0,1,2 would be reserved for SPI BUS: CLOCK, MOSI and MISO
  • GPIO 3,4,5 would be used as SELECT for 3 SPI Devices
  • GPIO 6,7 would be used as SDA and SCK for the I2C bus, allow to control up to 127 devices
  
  

• UART

  Nusbio can also play the role of an UART (FTDI cable, FTDI Friend) to upload data into an micro-controller like an Adafruit Trinket or Diavolino.
  The .NET library MadeInTheUSB.Lib.dll does not support this mode. The Arduino IDE will support Nusbio to upload code into an micro-controller with no UART.
  

  Videos

  • Nusbio - Nusbio As a FTDI Cable Adapter - PART I 
  • Nusbio - Nusbio As a FTDI Cable Adapter - PART II 

•  Library/Assembly

  • The MadeInTheUSB.Nusbio.Lib .NET assembly give access to the Nusbio device to any .NET language.
  • The MadeInTheUSB.Nusbio.Components assembly contains classes for specific components including the one used in the Nusbio's extensions.
  • Github Source
  
  

• Internal EEPROM

  Nusbio can store up to 32 bytes of data into the Description field. Though the Description property is a .NET string, the EEPROM only support ASCII string.

• Unique Serial Number

  Each Nusbio device is initialized with a unique Serial Number. See property SerialNumber.

Chip

Nusbio is based on the FTDI FT231X chip (Datasheet) or the FT232RL.
In 2017 only the FT232RL chip is used.

SPI EEPROM 25AA256 C++ Class For Arduino

Somehow I could not find a class for the SPI EEPROM 25AA256.

I created one. See Source on Github.

First test report reading the 32Kb in 215ms which means ~ 152Kb/s at 10 Mhz.

How to plug and control an Liquid Crystal Display (LCD) into a Windows machine (C#)

How to plug and control an Liquid Crystal Display (LCD) into a Windows machine

Do you wonder why you can do some neat things with a Raspberry PI and Linux and hardware, but not with your PC and Windows.

With Nusbio, you can talk to other devices from a Windows machine using any .NET languages.

In this blog I show different i2c LCDs (Liquid Crystal Display).

A regular LCD requires a lot of wires. An i2c LCD requires only 4 wires (GND, 5V, DATA LINE and CLOCK LINE). The first i2c chip supported is the PCF8574. Other chip should easy to support.

LCD 16 columns 2 rows

$26 USA Shipping Included: Nusbio Board + Liquid Crystal Display 16x2

LCD 20 columns 4 rows

Videos

Short

Nusbio - i2c 20x4 LCD Controlled With Some C# Code - Part I 

Nusbio - i2c 20x4 LCD Controlled With Some C# Code - Part II

Source Code

Demo

Library

How to plug and control an Liquid Crystal Display (LCD) into a Windows machine

Do you wonder why you can do some neat things with a Raspberry PI and Linux and hardware, but not with your PC and Windows.

With Nusbio, you can talk to other devices from a Windows machine using any .NET languages.

In this blog I show different i2c LCDs (Liquid Crystal Display).

A regular LCD requires a lot of wires. An i2c LCD requires only 4 wires (GND, 5V, DATA LINE and CLOCK LINE). The first i2c chip supported is the PCF8574. Other chip should easy to support.

LCD 16 columns 2 rows

$26 USA Shipping Included: Nusbio Board + Liquid Crystal Display 16x2

LCD 20 columns 4 rows

Videos

Short

Nusbio - i2c 20x4 LCD Controlled With Some C# Code - Part I 

Nusbio - i2c 20x4 LCD Controlled With Some C# Code - Part II

Source Code

Demo

Library