Log in

No account? Create an account


Pi time

« previous entry | next entry »
27th Jun 2012 | 22:36

Yesterday evening I finally did something with my Raspberry Pi.

I bought a few things to go with it: One is a "starter kit" which contains a holder for the RasPi and a breadboard and a few components. I thought this would be a good low-investment way to try out a bit of electronic fiddling. The other is a radio clock receiver. I'm not actually sure if it's an MSF or DCF77 receiver since the supplier seems a bit confused.

The clock receiver needed the ferrite aerial and some jumper leads soldered to the board. Ian Jackson kindly agreed to let me use his workshop and provided helpful advice. The last time I did any soldering was about 20 years ago, so I was quite pleased that I didn't make a complete hash of it. I took pictures of the bottom of the board and the top so you can judge for yourselves.

After returning home I got out the RasPi and plugged a few components into the GPIO pins. I then fired it up and started working out how to drive them. The path of least faff and greatest learning seemed to be to type in the example C driver code from the wiki. Before very long I turned on an LED. Woo!

After a bit more fiddling I got the clock receiver connected and I had a program that echoed its output signal to the LED. There's actually a tiny status LED on the receiver, so the two flash in unison. Unfortunately they aren't flashing a pulse-per-second signal: the receiver is only receiving noise, with maybe a PPS buried in there somewhere. Bums.

| Leave a comment |

Comments {2}


from: pjc50
date: 28th Jun 2012 08:44 (UTC)

Noise back-injected from the Raspi over the powerlines perhaps? Sort of thing that's quite hard to debug without a scope. If you want to lend it to me I can have a look with the office's scope?

Reply | Thread

Tony Finch

from: fanf
date: 28th Jun 2012 09:51 (UTC)

Yes, that was the suggestion from the time-nuts list too. I quess cheap-as-chips wall warts aren't designed for this kind of thing :-)

Reply | Parent | Thread