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Midlands User Group 15 September 2012

Venue - Methodist Church Hall, Blackwell, Bromsgrove B60 1BL
12 people at the meeting, with some apologies.
Our new attendee was Mike Buckland
Show Details
Kenilworth St John's Hall on 9th July. Ticket price £3. 11am to 4pm
Open for members/exhibitors at 9am. STUART to be there in time to let them in.

MUG meetings are held on the third Saturday afternoon of odd numbered months.

September's meeting was noticeably different from most, in that it was virtually completely hardware orientated. We intended to share experience of Raspberry Pi machines.

Throughout, the meeting was highly animated, with everyone (including a first time visitor, Mike Buckland) taking an active part or watching the simultaneous demonstrations of these remarkable devices.

Everyone knew something about them, and six members brought along their machines. For those of us who had never seen an RP they were something of a revelation. Necessary accessories also brought along included two large monitors and a selection of keyboards, plus a substantial array of connectors, power supplies and leads, and smart phones, for attempted access to the internet. Vic had also brought a powerful Samsung laptop with an i7 processor and a big range of storage and access facilities, which was used to help some members get their RP machines running successfully.

The six proud owners were Ron Briscoe, Vic Norman, Steve Read, John Rickman, Ralph Sillett, and Doug and Ben Webb. Most RPs were clothed in various protective containers, some were quite naked, one came directly out of its original packaging and another was routed from a block of solid mahogany.

Vic and John immediately settled down to running their machines under RISC OS, and they set up connections via a hub. Members were treated to an impressive demonstration of some of the capabilities of RPs, and the way in which they could exploit the power of large high definition displays, running under both their native Linux and RISC OS. Then of course RISC OS applications were run. In the course of this it was found that several such applications would not run on a Pi, but there was insufficient time to pursue the reason(s) for this. Steve's machine was shown to have been supplied with a faulty system card - something that Vic was able to sort out.

An interesting "discovery" led to an explanation of the inability of Pis running under the same operating system to connect to each other via a hub. They seem to be clones, thus having the identical MAC address which means that only one machine is recognised on a network. However, a Pi running under Linux (and with a different MAC address) was able to talk to one running under RISC OS. Members thought that this was a strange state of affairs since the machines might well need to be used in situations in which many (say 30), in a classroom might wish to communicate with each other.

Another discovery was that RPs seem to be quite sensitive to the specifications of their power supplies. Five volts is the nominal specification, but it appears that a supply in which the output voltage drops under the RP's load to less than about 4.7 volts will not be adequate. The supply must ideally be able to maintain very close to 5.0 volts when loaded to 2 amps.

The meeting closed without a definite theme for the next one (Nov 17th) being discussed. No doubt this will be decided in adequate time.