FOX Board G20 1-wire wirings

Following is an example on how to wire a DS18B20 thermal sensor to the FOX Board G20. The resistor used to pull-up the 1-wire bus is a 4,7 KOhm.

It is possible to link more than one sensor. I tried up to five. The driver will automatically acknowledge the sensors wired.

 Note:   This example will not work using the default microSD bought from Acme after October 25, 2011 or using the R18 version available on the .
Please use the following uImage where the 1-wire bus has been moved back to J7.5 pin (PB16) as it was when I wrote this article.

Changing the 1-wire bus GPIO line

It is possible to use any GPIO line of the FOX Board because the 1-wire is not implemented in hardware but is provided by the software bit banging Linux driver called w1-gpio.c.

To select which GPIO line to use for 1-wire bus service you have to configure it by changing the board initialization code inside the Linux Kernel. The source code is board-foxg20.c and the line to change is # 215.

To get the Linux sources and compile your own Kernel image follow this article: Compiling Linux Kernel 2.6.38 for FOX Board G20 and Netus G20.

FOXG20
EUR 139.00


FOX Board G20

FOX Board G20 is a "ready-to-run" Embedded Linux System perfect to use as a solid state WEB server or as a core engine for your embedded appliances.

A fully Open Source environment is available to customize and build your own kernel image or to develop user applications using standard GNU tools. Version with Atmel AT91SAM9G20 with 256KB of FLASH memory, 64MB of RAM and up to 16GB of microSD.

FOXG20 needs some extra accessories in order to be operative:

  • a bootable microSD with Linux OS (see DEBM2G or DEBM4G products)
  • a 5 Volt DC power source (see PS5V1A product)
  • a 3V lithium battery for internal RTC circuitry (see CH23-1220 product)

An evalution kit with all the accessories you need to get started with FOX Board G20 is available on-line on this link: COMBO-2.

Please note

Currently the FOX board G20 are shipped without the daisy connector mounted on top. If you need these connector please ask.

| Product description |

DS18B20
EUR 5.00


1-wire Dallas DS18B20 thermal sensor

The Dallas/Maxim DS18B20 is a 1-wire digital thermometer:

  • Measures Temperatures from -55°C to +125°C (-67°F to +257°F)
  • ±0.5°C Accuracy from -10°C to +85°C
  • Programmable Resolution from 9 Bits to 12 Bits
  • Each Device Has a Unique 64-Bit Serial Code Stored in On-Board ROM

| How to use with the Acme boards | Product description |