Hardware complete and tested

A project log for Data Collection Terminal

General purpose low cost handheld terminal with screen/kbd, wifi, barcode and RFID reader for industrial or commercial (or any other) use

BozBoz 04/28/2015 at 00:590 Comments

The final version of the hardware using the new RFID card is now working. Circuit and PCB are available on the EasyEDA site

Last minute changes include using filter glass to enhance the performance of the bar-code scanner, I tried both samples of commercial filter glass ($4 a piece!) but the red transparent films used for hobby and crafts you get off eBay seem to do just as good a job (I cannot measure the filter but I guess it hits that 625nm sweet spot for the CCD just as sweet. I have also updated the MPU to the PIC32MX250 as there are some USB boot loaders already available for this.

The RC522 RFID chip already has some public domain C++ libraries and seems easy to use (though a bit complex for what I need) with the move to 13Mhz I can now program the SSID, password and encryption keys directly into the RFID tags so security is as good as it gets and much better than I actually require due to other factors.

First unit is still a collection of drivers and test procedures which I will eventually put on git hub (I don't really use git-hub properly. one day I will get around to learning it but for now its a place to throw releases when I think I've hit a milestone)

Pictures below.

First picture showing the unit with the RFID card fitted. The ESP-01 module is right at the bottom and under the main PCB, bar-code reader is about 1cm from antenna but does not seem to affect performance.

Second picture (above) is with the RFID removed exposing the guts of the unit. ESP-01 module can be seen flush with top of case (PCB is screwed to top of case with LCD mounted on the back)

Last picture

I am getting some cases cut in black ABS, the grey is so 1980's in most peoples opinion! The window is actually more orange but it filters some of the flash colour.

Note all the parts work and have been tested individually, the next step is finish off programming and to get 30 boards assembled and into the hands of my hopefully eager users!