Legal Removal Request

Post: I have added the links to the Expander Pi page for the I2C and SPI tutorials, I didn't realise that they were not already included on the product page. There are a few things you can do to check if the Expander Pi is working correctly. First, can you check that you have a fully charged CR2032 battery in the battery holder, it should be at 3V. If the battery voltage is low then this would stop the RTC from working. Try running sudo [b]i2cdetect -y 1[/b] in a command shell to check which I2C devices are available. i2cdelect will show a grid of the available i2c addresses with the used addresses appearing as numbers in the grid. The IO chip should appear on address 0x20 and the RTC is on address 0x68. If these do not appear then there is a problem with either the I2C configuration on the Raspberry Pi or the I2C port on the Expander Pi. Do you have any other I2C devices connected to the Raspberry Pi that are using addresses 0x20 or 0x68? If the pull-up resistance on the Expander Pi I2C lines drops below 5K the voltage level translator stops working and extra I2C-based expansion boards connected in parallel could drop the resistance below 5K. This is why on the Expander Pi product page we recommend only using two of our other boards alongside the Expander Pi and not using our 1 Wire board with the Expander Pi as that uses a 2.2K pull-up resistor. If i2cdetect shows both of the I2C addresses then can you try running some of the other demo scripts in the Expander Pi library folder? [b]demo-ioread.py[/b] will test the IO chip to check that it can read the input pins. [b]demo-rtcsetdate.py[/b] will test the RTC chip by setting a date and then reading it back to the screen. [b]demo-adcread.py[/b] will test the ADC chip on the SPI bus and [b]demo-dacwrite.py[/b] sets an output voltage of 1.5V on the DAC channel 1 and toggles it on and off at 1-second intervals. By running each of these scripts we can work out which parts of the Expander Pi are working. If only one part is failing then that means there is probably a fault with the Expander Pi and I will send you a replacement.