Why so quiet?

Well I have actually been busy. Two of the electronic boards have gone into production and a third more complicated 4-layer board is nearing completion for the client. Unfortunately these wont be open sourced as the client has some close competition in the market. I normally try and stick to 2-layers unless I am dealing with special cases like high frequency mixed signal or like this where there simply is too much going on to even consider 2 layer (80 pin CPU with 10 multiplexers, DAC, 2 op-amps and 6 uln driver chips and two power supplies on a 100cm square board) still designing with 4-layer is also easier as you get a dedicated ground plane which is easier to shape to separate the analog and digital paths and much easier to solder as you tend not to need another ground plane on the component sides of the board.

Ahh the joys of prototyping tiny little components when your eyes are getting old!

And after my bad soldering effort!

You may also have heard we also had a bit of a shake just after my last post with a 7.8 earthquake north of Kaikoura about 80Km away, It wrecked the lab and workshop which was at peak mess at the time toppling most of my test equipment and monitors on to the floor and spewing thousands of 0805 components around like snow. My old Owon scope cracked its screen but otherwise no physical damage to anything or my house. The joys of living 2M above and 200M away from the Pacific Ocean are easily forgotten when your shaken awake at midnight and have to get to high ground in your underpants!

I am also doing a re-design of the Data Collection Terminal for another possible client. WiFi is proving to be a pain for them on their large sites and the new design will use either the RFM69 or RFM95(lora) 868Mhz modules (which have compatible footprints and are interchangeable) which should allow a single or at most 2 base units to cover the site and improve battery life. Due to the design of the mobile unit the data rate is very low and so it fits quite well with these modules where low data rates = low bandwidths = quite long ranges. I have not yet put the designs up as they are changing frequently as I experiment with different configurations, the mobile enclosure will remain however I will remove the USB and LiPo battery for 2 x NMHi AA ones which should last several weeks (without a proper enclosure the USB connector had to be cut-out and looked unprofessional) I have also changed the Keypad layout to a standard 4×4 matrix (Nicer IMHO). Oh and we are back to a 125Khz RFID but with a $2 EM4100 module (less than half the price of the chip I was using)!. So basically apart from the enclosure, barcode reader and LCD it is completely different! I was going to use a ATMega328PB to keep my arduino friends happy but the PIC18F26K40 just came out and is twice the Flash and RAM and cheaper.. decisions.. decisions..

The bare bones of the MKII Data terminal (Warts and All!)

The new keyboard overlay was far superior to the original one in every way and came to  US$610 for 100 pieces including courier to NZ which is half the price of my other supplier so shout out to Haiwen Membrane Switch Limited who i will definitely use again

Of course the usual suspects want changes to their respective systems and so everything has to be prioritised, with only one of me and vintage looming this is proving troublesome.

Finally My daughter Alex has turned 21 (today! Happy Birthday) and finally moved on to another full time job in AON in corporate Auckland, I’m going to miss her help, my wife has offered to help by doing my accounts and filing which should free up some time for me and fill the gap a bit

This entry was posted in Uncategorized. Bookmark the permalink.