Bluetooth has arrived!

A project log for Getting online with a 1987 Psion Organiser II

Bringing an Eighties handheld classic into 2020 with a little help from a Raspberry Pi and a Bluetooth chip.

James FosseyJames Fossey 02/28/2020 at 20:490 Comments

Finally the Psion Organiser II has joined the wireless revolution!

I purchased an HC06 chip for the princely sum of £3.85 off eBay. This chip converts the TTL signals produced by the Psion Comms Link to Bluetooth radio signals and vice versa. With a bit of crafty soldering, I wired up this HC06 chip to the Comms Link - this was actually quite easy, because I had already soldered the necessary wires to the Comms Link in an earlier part of the project - see log entry 'Back in action' from 2 Sep 2019 and the pictures in my last log.

It works better than I expected (i.e. it actually works!) Using a Linux program called 'rfcomm' (I'm guessing this means radio frequency communication) I can control a terminal session on the Pi from the Organiser wirelessly at a distance of a few metres, at the lightning-fast speed of 9600 baud. All I needed to do was 'pair' the HC06 Bluetooth chip with the Pi (this is fairly straightforward so I won't go into the details here) and then use a little 2-line script to generate a terminal session over Bluetooth, which I'll attach to the project page when I get a mo. I can even transmit/receive files to/from the Pi from/to the Psion (delete as applicable!) via the XMODEM protocol, using the 80s software built into the Comms Link chip. I find this very exciting, which says a lot about me ;)

Most pleasing of all though - my modified Comms Link with its added circuitry still just about fits inside the original Comms Link case* so that's a bonus if I ever venture out in public with the Organiser II again. Which I probably will :)

I don't plan to enhance the design any more; I'm pretty satisfied with it,  given that I'm not an engineer or anything, just someone interested in old technology with a bit of Linux knowledge and an old soldering iron. I'll hopefully put together some photos and maybe a bit of a summary when I get the time. Until then, enjoy some pictures of 1987 crashing awkwardly into 2020 in the form of my Bluetoothed Comms Link.

The added HC06 Bluetooth chip is appropriately coloured. Note the resistors - these connect to the TXD pin on the HC06 which together form a potential divider (the Psion outputs 5V, the Bluetooth chip only takes 3.3V)
Slightly blurry close-up

*though unfortunately it doesn't screw back together properly any more as I had to savagely snap off the 'tunnel' for the screw (engineers probably have a technical term) with a flathead screwdriver in order for the chip to fit. Elastic bands may be a solution.