54 SERVO 10.2017
Part 1 also reviewed the I2C protocol, and developed flowcharts and a Verilog state machine (i2c_interface.v). Part 2 showed how to integrate the interface module with
a top level design, create a clocking structure and pinout, and
how to implement the test design in the Xilinx Vivado® tools.
Here in Part 3, I will show how the final bitstream can be
downloaded to the ARTY board and the Xilinx hardware
debugger used to observe the data results coming from the
PMOD sensors. The resulting temperature values are compared
against ambient conditions.
Testing the Design
To program the compiled design (bitstream) into the ARTY
board, connect a USB cable (standard-A plug to micro-B plug) to
a laptop with the Vivado cable drivers installed and attached to
the ARTY board micro USB connector. Ensure that the PMOD
sensor is plugged into the top row of pins (numbered 1-6) on the
PMOD JA connector.
Programming and working with the ARTY board does not
require a separate Xilinx programming cable, and power is
supplied to the board via the USB cable. Figure 2 shows how
In Part 1 of this three-part
series, I discussed the creation
of an I2C interface for a Silicon
Labs PMOD sensor combining
an Si1145 proximity/UV/ambient
light sensor with an Si7020
humidity/temperature sensor as
shown in Figure 1.
Interfacing an FPGA
with the Digilent Arty™ Board
Part 3 By Steven Howell
Figure 1. Silicon Labs’ PMOD sensor (Si7020 / Si1145).
Figure 2. Digilent ARTY evaluation board with SiLabs PMOD sensor attached
(broadcast I2C reset transaction on scope).