Yearly archives: 2016


Hello World for EPICS

As a new user to EPICS — an open-source, distributed, control system normally used to control large-scale particle accelerators — I wanted a nice soft introduction to the first steps of installation and implementation.  I was looking for an EPICS equivalent to the “Hello World” code normally used as the […]


Easy EPICS implementation with Docker

Many times I want a throw-away implementation of a system I am working on.  Something that allows me to quickly develop an idea, try a theory, or make a quick test of some code.  A good solution to problems like this is to use Docker to launch a container that […]


A user-friendly software stack

In a previous post, I considered how to make the set-up of a RaspberryPi–Arduino EPICS system more user-friendly.  Well, after a long, Java-based, digression that ended in a several-thousand lines-of-code deadend, I have ended up with a working solution. Click here. Web-based applications Without going into the details of the […]


Making the software stack user-friendly

In a bunch of previous posts over the last 6 weeks or so, I have built up an open-source software stack for controlling Arduino-based gadgets.  This was based on the use of serial communications to send/receive command-response queries to the Arduino via an EPICS IOC installed on a Raspberry Pi.  […]


Altering the FPGA clock frequency of the Mojo

The Spartan 6 FPGA that comes with the Mojo uses a default clock frequency of 50 MHz.  While this is sufficient for almost all tasks, there are times when it might be necessary to increase that.  For example, I have a particular use-case that requires a 14-bit PWM signal to […]


Follow-up to LED characterisation

In a previous post I outlined a preliminary plan for how to configure an FPGA to characterise the response of a photoresistor to illumination by an LED whose brightness was controlled via the duty cycle of a PWM signal.  In that post I wrote that the required behaviour suggested a […]


Characterising system response with an FPGA

Due to a need to add an FPGA to the control stack that I have been developing (please see the previous 4 or 5 blog entries), I have started to plan the implementation of a PID feedback loop on the Spartan 6 Xilinx FPGA that comes with the Mojo development […]