Linker kit Base Shield for Raspberry Pi with ADC Interface

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Revision as of 16:15, 29 July 2013 by Jingfeng (talk | contribs) (Tutorial)
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Description

This is a Linker kit base shield for Raspberry Pi with ADC interface. All the Linker kit modules can be plugged onto Raspberry Pi through this base shield. Moreover, this shield has an on-board ADC chip so that analog output modules can be used on Raspberry Pi. The ADC chip used is MCP3004. It talks to Raspberry Pi using SPI interface.

P24-1.jpg


Specification

There are 8 4-pin 2.54mm spacing housing on the base shield:

  • JP1: A0, A1, VCC, GND.
  • JP2: A2, A3, VCC, GND.
  • JP3: SCL, SDA, VCC, GND.
  • JP4: RXD, TXD, VCC, GND.
  • JP5: P17, P18, VCC, GND.
  • JP6: P27, P22, VCC, GND.
  • JP7: P23, P24, VCC, GND.
  • JP8: P24, P4, VCC, GND.

These connectors cover Analog, I2C, and GPIO.

Install Base Shield on Raspberry Pi

P24-3.jpg

Schematics

Tutorial

RPI ADC base shield 教程 中文版

The ADC chip used on this base shield is MCP3004 (10 bit resolution, 4 channels, SPI interface). In the following, we are going to cover how to use Python to read the ADC output:

As we use SPI communication, we need to enable SPI module in kernel. To do that, we can edit the blacklist of kernel, and enable spi:

sudo vi /etc/modprobe.d/raspi-blacklist.conf Locate the line begins with "blacklist spi-bcm2708" and change it to "#blacklist spi-bcm2708".

After this, we can check the module by "lsmod", and observe the following content:

Module Size Used by spi_bcm2708 4421 0