A good way to expand Telecom Design system is to use I2C to connect external devices. As an example I had to add an extra Analog to Digital converter. I’m using a MCP3021Ax device. This I2C chip just return a 10bits value each time you send a READ at the expected address. This post contains the TD1204 code to configure I2C and get the data back
The new version of kernel now activate the device-tree standard, it means that instead of having all module activated by default with some stopped by a blacklist system, now, all are disable and activated only when described in a device tree.
Device tree details the system architecture and dependencies following configuration files. The device tree can be owned by the shield itself in an attached eprom.
As a consequence, now, i2c / spi are not activated by default. So if you need to activate it on startup. For this, edit /boot/config.txt and add line at the end like :
dtparam=i2c_arm=on # for i2c 1 dtparam=i2c_vc=on # for i2c 0 dtparam=spi=on dtparam=i2s=on dtparam=i2c_arm=on,i2c_vc=on
Some new hacking on Raspberry PI, the objective is to get a TC74A5 3.3VAT temperature sensor working with a RPI. This sensor is a digital sensor type 2 wires I2C operating at 3.3V with a precision of 2°C.
Read next to get details