Linux – JackenHack

Quartus Prime FPGA USB-Blaster Problems On Ubuntu 18.04

January 12, 2020 by Jack Zimmermann 5 Comments

I’ve decided to learn how to program FPGA:s. So I got myself two Terasic boards, one Terasic DE10-Nano for testing out the excellent MiSTer FPGA hardware arcade/computer/console emulator and a simpler DE0-Nano for beginning to learn Verilog.

But the software used, called Intel Quartus Prime 19.1, is truly horrible. The Windows version doesn’t work with high-resolution screens when using scaling; the text is cut off on the display. So I installed it on my Linux Ubuntu 18.04 machine instead. Now the display works, but there’s a lot of other problems, like getting the dreaded error message: “USB-Blaster unable to scan device chain”. I’ve written them down here for later reference, and maybe you have the same install problems, so this might help.

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DietPi Makes Your Raspberry Pi a Lean Mean Linux Machine

April 13, 2017 by Jack Zimmermann Leave a Comment

My wild guess is that most people get a small Linux computer, like the Raspberry Pi, BeagleBone, Banana Pi or Orange Pi for a specific task. Unfortunately, most distributions are chock-full of software, with everything installed per default. But if you want to set up a lean single board computer for a specific task, you’re out of luck. Thankfully there is a Linux distribution, DietPi, that aims to fix that problem.

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NTP Server Extreme accuracy for under $200 Using SI5351C

April 13, 2017 by Jack Zimmermann 2 Comments

When you make your own NTP server, you probably spend a lot of time trying to get it as accurate and stable as possible. To get good results, you need to connect your server to a good time reference, like an atomic clock, GPS or a GPSDO to get the PPS (Pulse Per Second) to sync your server with the reference clock.

In both Linux and BSD, there is kernel support to slave the very inaccurate CPU clock crystal to the PPS signal, continually adjusting the frequency, because the crystals of computers continuously drift due to temperature and barometric pressure differences. So most of the work is to get a crappy crystal to behave. What if you just jumped over that step, so the CPU clock gets synchronized with the same lab reference that the PPS signal uses, using a SI5351C Clock Generator?

Read on to see a simple way of doing it and get an extremely accurate NTP server for under $200.

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Raspberry Pi 3 Overclocking Heatsink Cheap

December 17, 2016 by Jack Zimmermann 19 Comments

I needed a cheap heatsink for my Raspberry Pi 3 that I use as a music player/server. To maximize performance, I wanted to overclock the computer for faster searching and handling of all my music. I’ve managed to overclock my central Stratum-1 NTP server to 1350MHz without any problems, but the dinky little aluminium heatsink was way to anaemic, so I found a very cheap DIY solution to my question. With this heatsink, I can run the Raspberry Pi 3 at 1.5GHz all day at full tilt without any issues!

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Increase Pulse Width 1 PPS signal from GPSDO

January 28, 2016 by Jack Zimmermann 3 Comments

Update: You can download the Eagle PCB files for the PPS Pulse Width Extender here.
The PCB is made to fit the Hammond 1455C802BK enclosure.

I have two Stratum-1 NTP servers using Raspberry Pi 2’s as servers. But the two setups are entirely different.
My primary NTP Stratum-1 server is available at ntp.jacken.se, but it is also in the .se pool of ntp.org. ~~It’s a Raspberry Pi 2~~ I use a Raspberry Pi 3 that I have connected a U-Blox Neo-7 GPS receiver. But I’m not using the 1 PPS signal coming out of the U-Blox. I have a Trimble GPSDO that I bought from eBay. The unit has two 10 MHz lab reference outputs and one 1 PPS output. But after measuring the signal coming out from the GPSDO, I realized that the timing speed for the seconds “Tick” was only 10 µsec which is way to fast for the Raspberry Pi to pick up as an interrupt on one of the GPIO pins. So I built a pulse extender, making the pulse around 250 milliseconds instead. And now the Raspberry Pi picks up the pulse without problems. Some GPSDO units can set the pulse width by programming the unit via a serial port, but I can’t find that feature on this unit (which is poorly documented and was OEM made for some other manufacturer), so I had to do it with hardware. So how does it look when crunching the numbers on it?

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