RF2500 in more detail

I got myself a macro lens for my EOS350D for taking photos of electronics, so here the RF2500 is in more detail.

Ordering RF2500's from Alibaba

With the success of the 43oh.com guys in ordering from Alibaba, I thought I'd like to organize some - Tim from MindKits said he'd buy some as well (20 - go there soon if you want some). They are pretty tiny, but solderable. They are designed so you can put header pins in them and solder them onto boards as modules or fit a plastic cap over them of some kind if you want to stand it upright. Once I get my MezzoMill, I'll print a board out that will let me use them more easily, but for now I will just solder wires into them and stick them in a breadboard :-)

My intention is to write drivers for the RaspberryPi for them and also for the MSP430.

I am expecting I'll need to use the BusPirate I ordered from SeeedStudio (to support Dangerous Prototypes, the only reason I didn't order from MindKits who get it via SparkFun don't pay DP a bean for it) to debug my SPI work.

Buying from China on eBay

With good stories from other people, I decided to try my hand at purchasing some items on eBay that I wanted in my kit - and first to arrive is the 16x2 backlist LCD based on the Hitachi HD44780. It took around a month to get them here (New Zealand) from China, a little longer than they said, but it was Chinese New Year in between so I did expect that. They were certainly not the cheapest of the ones on there, but many didn't ship here, so they were ruled out.

They were well packed with plenty of bubble wrap and arrived undamaged.

I soldered one of them up with header pins and attached them to my bread board, which immediately pushed the not soldered well enough ones back out again.

So on the second go I was successful with all but the final pin which I was worried about the soldering anyway - I am using a very fine tip on my Hakko and am very pleased with its performance.

Wiring it all up, figuring out how the LCD backlight is turned on and skipping the trimpot all made for a nice experience. I used the sample Arduino sketch just to check the device out to ensure it was working as expected - I didn't want to go through the same with the MSP430 Launchpad as I haven't put headers on my board yet.

Works exactly as advertised and i'd recommend the seller for people looking for these LCD devices.

Radio

I dislike the Arduino platform for one main reason - its focus on for loops with delays. I understand that the Atmel chips can work primarily on interrupts and in lower power, but the MSP430 Launchpad from TI is really focused on low power. Its not a board for beginner programmers (though EasyMSP may help that). Why low power? I know not every board wants or needs this, but radio in my opinion is where it is at - building something and then having it having no connectivity is just plain weird. Every single project I think of, I want to have it being monitored. I have yet to find the perfect radio kit - I think I'll want a sensor net of RF2500's (as they are cheap boards - around $US2) - they have a range of 30-50 metres and something like an RFM22B ($US13, SPI) or Doji ($NZ30, UART) board for longer range. And there is always RFID for ultra short ranges (<20cm).

PCB really need to be easy

So although we managed to get the circuit working, as soon as we stuffed it inside the mouse it short circuited and parts started failing, which is what I expected unfortunately. So we decided to try and get a perf board and went to Jaycar and got a selection of two different types - one with the copper all along and one with the copper in various patterns. Unfortunately, with this mouse case it really showed up one of the things that continues to frustrate me - which is that it really needed its own PCB.

I'm not at all experienced in PCB layout or manufacture, and one of the reasons I have stayed away for so long is the mess. Chemical processes using etching at home are just plain nasty, and all the processes people seem to be going through to get around this still seem messy and nasty.

So over the xmas period, I found there was a Kickstarter project called MezzoMill - a CNC machine that a guy (David) has put a huge amount of effort into making a really good method for just printing from Eagle. The Kickstarter failed unfortunately, which is pretty sad, but I talked to David directly and he said ok to build a MezzoMill for me and shipping it out here. This, I am totally buzzed about - more so than the 3d printer (Replicator) that I ordered from MakerBot.

Time will see if its just another folly, but hopefully not!